Prevention of Reinforcement Corrosion in Concrete by Sodium … · 2019. 7. 30. · Prevention of...
Transcript of Prevention of Reinforcement Corrosion in Concrete by Sodium … · 2019. 7. 30. · Prevention of...
Research ArticlePrevention of Reinforcement Corrosion in Concrete by SodiumLauryl Sulphate Electrochemical and Gravimetric Investigations
Binsi M Paulson1 Thomas K Joby 1 Vinod P Raphael 2 and K S Shaju 2
1Research Division Dept of Chemistry St Thomasrsquo College (Autonomous) Thrissur Kerala 680001 India2Dept of Chemistry Government Engineering College Thrissur Kerala 680009 India
Correspondence should be addressed toThomas K Joby drjobythomaskgmailcom
Received 24 August 2018 Revised 27 October 2018 Accepted 13 November 2018 Published 2 December 2018
Academic Editor Ramazan Solmaz
Copyright copy 2018 BinsiM Paulson et alThis is an open access article distributed under theCreativeCommonsAttribution Licensewhich permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited
Prolonged corrosion inhibition response of sodium lauryl sulphate (SLS) on steel reinforcement in contaminated concrete wasinvestigated by gravimetric method and electrochemical techniques such as potentiodynamic polarization and electrochemicalimpedance spectroscopy Using half cell potential measurements probability of steel reinforcement corrosion was monitored fora period of 480 days FT-IR spectroscopic analysis of the corroded products deposited on the steel reinforcement revealed themechanism of corrosion inhibition Modification in the surface morphology of steel specimens in the concrete was examined byoptical microscopy During the period of investigation (480 days) SLS showed appreciable corrosion inhibition efficiency on thesteel reinforcement in concrete
1 Introduction
Reinforced concrete structures are developed to ensure thestrength and existence throughout their lifetime But thedeterioration and collapse of reinforced concrete structureare a major issue in construction field [1ndash3] CO
2from
the air and chloride ions from the sea atmosphere enterinto the concrete and make the concrete interstitial solutionmore aggressive than before [4ndash8] Depassivation of the steelreinforcement occurs locally in the presence of chlorideions leading to pitting corrosion [9ndash12] Passivation of steelreinforcement takes place due to the alkaline compoundspresent in the concrete The cost of replacing deterioratedconcrete structures may affect the GDP (Gross DomesticProduct) of a country To find out an effective and economicmethod to combat the steel reinforcement corrosion inconcrete has been attracted by the researchers and engineersfor the last two decades
Addition of the corrosion inhibitors to the concretemixture is the most practical way tominimize steel reinforce-ment corrosion in contaminated concrete [13ndash16] In idealsituations corrosion inhibitors will not affect the propertiesof the concrete Some of the previous researchers havebeen established that inhibitor molecules generally affect the
kinetics of electrochemical process of corrosion of steel [17ndash19] The mechanism of corrosion inhibition by the addedcompounds may include lowering of the rate of diffusionof chloride ion enhancing the threshold value of chlorideion and lowering the rate of anodic and cathodic process ofcorrosion [20ndash22] Corrosion inhibitors can be added to thefresh concrete as an admixture during concrete casting stepor can be applied on the concrete surface
Commercially available corrosion inhibitors may containeither organic or inorganic compounds like sodium nitritesodium monofluorophosphate aminoethanols and so forth[23ndash27] Nowadays use of nitrites is not recommendeddue to its toxicity The efficacies of organic inhibitors aresometimes questionable at elevated chloride concentrationsResearchers scientists and engineers are always in searchof potent economic and environmental-friendly admixturesto combat steel reinforcement corrosion in concrete Somerecently invented green inhibitors like silver nanoparticledoped palm oil leaf extracts [28] and naturally obtainedWelan gum and Neem gum [29] have predominant concretecorrosion inhibition efficiency
Present investigation was conducted to check the cor-rosion preventing capacity of SLS on steel reinforcement
HindawiInternational Journal of CorrosionVolume 2018 Article ID 9471694 10 pageshttpsdoiorg10115520189471694
2 International Journal of Corrosion
SS mesh
ElectrochemicalWorkstation
Rebar
Wet sponge
SCE
Figure 1 Three-electrode circuitry for electrochemical studies
in contaminated concrete [30 31] Preliminary examina-tions were done by measuring the electrode potentials ofsteel reinforcements (against SCE) dipped in concrete poresolution contaminated with 35 NaCl containing variousconcentrations of SLS After this examination we decidedto investigate the corrosion response of steel reinforcementin concrete specimen containing 25 of SLS by weight ofcement
2 Experimental
21 Materials Sodium lauryl sulphate and sodium chloride(gt999 ) were procured from Merck Millipore Portlandcement (Indiana Cements Grade 53) used for making con-crete specimens was purchased from the market
22 Preparation of Concrete Test Specimens Concrete blockscontaining steel reinforcement used for the experiment weremade of Portland cement coarse aggregate fine aggregate(sand) and water Each rectangular block having dimensionof 200x80x80mm was prepared by mixing water and cementin the ratio 05The ratio between cement fine aggregate andcoarse aggregate was 1153 which will exactly mimic M-20grade concrete SLS was added to the concrete mixture by25 wt of cement and two test specimens were casted Inthis work we designate the concrete specimen without SLSas SAMPLE 1 and with SLS as SAMPLE 2 The approximatecomposition of steel rod was estimated by EDAXmethod 01 P 062 Mn 0021 Si 004 S and rest Fe Steel rebarswere cut (22 cm) and immersed in 2M HCl for 10 minutesfor removing the rust washed with distilled water degreasedwith acetone dried weighed and used as the reinforcementin concrete After a period of 24 h the test specimens wereremoved from themould and cured for 30 days for the properhydration and setting of the cement
23 Treatment of Test Specimens After the curing periodfive sides of the test specimens were coated with epoxyresin and one open reservoir (100x40x20mm) was built onthe remaining side with polypropylene and silicon adhesive
25mL 35NaCl was added to the reservoir of the specimensand kept for 2 days This will ensure the complete diffusionof NaCl throughout the specimen This process was repeatedthree times during 30-60 days
24 Electrochemical Investigations
(i) Potentiodynamic Polarization Studies Figure 1 shows theschematic diagram of the test specimen and the experi-mental setup for electrochemical studies Three-electrodecell assembly consisting of steel reinforcement present inconcrete as working electrode concrete specimen coveredwith a stainless steel mesh as counter electrode and saturatedcalomel electrode (SCE) as reference electrode were used forthe electrochemical studies [32] For good electrical contacta wet sponge was used on the concrete surface between SCEand concrete surface
After curing and treatment of test specimens with NaClpolarization studies were performed three times during aperiod of 480 days in 160 daysrsquo interval Steel reinforcement inthe concrete was scanned for a potential range of +250 to -250mV having a scan rate of 1mVs Tafel curves were analyzedto get the slopes which are extrapolated to get the corrosioncurrent densities The corrosion inhibition efficiency of SLSwas determined using the following equation
120578pol =119868corr minus 119868
1015840
corr119868corr
X100 (1)
where Icorr and I1015840corr are corrosion current densities of steelreinforcement in test specimens in the absence and presenceof SLS respectively Experiments were repeated with theduplicate concrete block and the average values were taken
(ii) Electrochemical Impedance Spectroscopic (EIS) Studies EISexperiments were carried out at constant potential in thefrequency range of 1 KHz to 100 mHz with excitation signalof 10mV amplitude Analysis of the Nyquist curves using theequivalent circuit gave the charge transfer resistance (Rct)
International Journal of Corrosion 3
Table 1 Tafel data of steel reinforcement in concrete in the presence and absence of SLS for different periods
Time System Icorr ba -bc -Ecorr 120578pol (day) (120583Acm2) (mVdec) (mVdec) (mV)160 SAMPLE 1 161 496 159 651
SAMPLE 2 18 430 232 573 89320 SAMPLE 1 139 489 156 662
SAMPLE 2 41 469 229 520 71480 SAMPLE 1 107 373 215 551
SAMPLE 2 21 341 230 561 80
Using Rct values corrosion inhibition efficacy of SLS wasdetermined using the following equation
120578EIS =R1015840ct minus Rct
RctX100 (2)
where R1015840ct and Rct are the charge transfer resistance ofworking electrode with and without SLS respectively Polar-ization and EIS analyses were done using Ivium CompactStatelectrochemical work station (IviumSoft)
(iii) Half Cell Potential Measurements For understanding thecorrosion response of steel reinforcement in concrete halfcell potential measurements were carried out using saturatedcalomel electrode (SCE) and high impedance voltmeter (HPE2378A) In this electrochemical cell steel reinforcementand SCE were acted as anode and cathode respectively Thepotential of the steel rebar was obtained by deducting the cellpotential from the standard electrode potential of saturatedcalomel electrode Sixteen readings were taken with a regularinterval of 1 reading per month during 480 days
25 Gravimetric Method Before casting the concrete blockseach steel rebar was pickled with 2M HCl for 10 minuteswashed with water degreased with acetone dried andweighed The surface areas of all reinforcements were thesame (105cm2) After 480 days concrete blocks were brokenand the steel reinforcementswere taken outside pickled using2M HCl for 15 minutes to remove the adhered rust washedwith water dried and weighed From the weight loss of thesteel specimens approximate corrosion inhibition efficiencyof SLS was calculated by the following equation
120578 = 1199080 minus 1199081199080
times 100 (3)
where w0and w are the weight loss of steel rebars of SAMPLE
1 and SAMPLE 2
26 Spectroscopic Studies Fourier Transform Infrared (FT-IR) spectroscopic study of corroded product on the steelreinforcement was conducted using KBr pellet method Thespectrum was recorded in the range of 400-4000cmminus1 usingShimadzu IR Affinity-1 model FT-IR spectrophotometer
27 Microscopic Surface Analysis After 480 days of elec-trochemical investigation the steel specimens were taken
outside from the concrete and analyzed using a high-resolution optical microscope (Leica Stereo Microscope NoS8ACO) This study mainly aims to understand the surfacemodifications that occurred for steel specimen during theperiod of investigation
3 Results and Discussions
31 Potentiodynamic Polarization Studies The inhibition effi-cacy of SLS and site of corrosion inhibition on steel rein-forcement in the contaminated concrete wasmonitored usingpotentiodynamic polarization studies Analysis of polariza-tion curve gave Tafel slopes current densities and percentageof inhibition efficiency which are given in Table 1 Fromthe data it is understandable that the steel reinforcementin the concrete containing SLS was less corroded than rein-forcement in the SAMPLE 1 During 480 days three sets ofmeasurements were taken in 160 daysrsquo interval It was noticedthat SLS exhibited 89 corrosion inhibition efficiency on160th day of study On 320th and 480th days of investigationinhibition efficiency changed to 71 and 80 respectivelyFrom these results it can be assured that SLS can act asan efficient admixture which resists the steel reinforcementcorrosion in the contaminated concrete structures for a longtime SLS mainly acted on cathodic sites of corrosion up to23 rd period of investigation since the cathodic slopes of theTafel lines altered appreciably (Figure 2) But the corrosioninhibition response of SLS was changed into mixed type(affecting both anodic and cathodic sites) towards the end ofstudy
The gradation in the inhibition efficiency of SLS can beexplained with the help of following hypothesis The entireperiod of investigation can be divided into three stages firststage (0-160 days) second stage (161-320 days) and third stage(321-480 days) In the first stage SLS molecules adjacent tothe steel rebar make coordinate bonds with ferrous ions andprevent chloride ions and water molecules diffusing towardsthe steel surface considerably Thus during this period SLSprotects well the corrosion of reinforcement Towards theend of second stage (320 days) it was observed that the rateof corrosion slightly increased Since the rate of diffusion ofchloride ion is greater than that of SLS higher percentage ofchloride ions can be expected near the steel surface than thatof first stage The porous nature of the hydrated ferric oxidehelps to enter water molecules chloride and oxygen moretowards the steel surface Thus SLS showed less corrosion
4 International Journal of Corrosion
Sample 1
160 days320 days480 days
minus03minus05 minus04minus06 minus02minus08 minus07
Potential (V)
minus25
minus20
minus15
minus10
minus05
00
05
10
15
log
curr
ent d
ensit
y(Ac
m
)
(a)
Sample 2
160 days320 days480 days
minus07 minus06 minus05 minus04 minus03 minus02minus08
Potential(V)
minus35
minus30
minus25
minus20
minus15
minus10
minus05
00
05
10
log
curr
ent d
ensit
y(Ac
m
)
(b)
Figure 2 Tafel curves of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480 days
Table 2 EIS parameters of steel reinforcement in concrete in the presence and absence of inhibitor for different periods
Time Sample W Rs Cdl Rct 120578(day) (Ohmsqrt(Hz) (Ωcm2) (120583Fcmminus2) (Ωcm2)160 SAMPLE 1 274 785 110 119
SAMPLE 2 502 975 109 931 872320 SAMPLE 1 352 157 885 147
SAMPLE 2 927 459 42 665 78480 SAMPLE 1 323 223 273 243
SAMPLE 2 158 574 096 173 86
protection efficacy at this stage In the third stage (480 days)the rate of corrosion was seemed to decrease again (but not asthat much of first stage) During the end of this stage it can bebelieved thatmore andmore SLSmoleculesmigrated towardsthe steel surface from the bulk and make more coordinatebonds with ferrous ions and protect steel surface This led tohigher corrosion protection efficiency of SLS than in secondstage
32 EIS Measurements The corrosion response of steel rein-forcement in concrete in the presence and absence of SLS wasmonitored using electrochemical impedance spectroscopyand the corresponding Nyquist plots are represented inFigure 3 The corrosion behaviour of steel reinforcement wassignificantly differed in the presence and absence of inhibitorThe equivalent circuit fitted for EIS measurements (Figure 4)consists of solution resistance (Rs) which is connected inseries to double layer capacitance (C
1) and this combination
is connected in parallel to a series combination of Warburgresistance (W) and charge transfer resistance (Rct) [33 34]The EIS parameters of the test specimens are given in Table 2Impedance data show that addition of SLS leads to the
decrease in double-layer capacitance and increase of chargetransfer resistance This is due to the adsorption of SLSmolecules on the steel rebar SLS exhibited 872 corrosioninhibition efficiency on 160th day of investigation Inhibitionefficiencies changed to 78 and 86 respectively on the 320th
and 480th days of study
33 Half Cell Potential Measurements The probability ofcorrosion of steel reinforcement in concrete was visualizedwith the help of half cell potential measurements It wasestablished by the previous researchers that tendency ofcorrosion increases as the potential of the steel reinforcementchanges to more anodic side Half cell potentials (Vs SCE)of steel reinforcements in concrete blocks during 480 dayswere measured at a time interval of 30 days and are givenin Table 3 The half cell potential values are compared withthe help of a line graph and are represented in Figure 5Data show that the steel reinforcement in concrete block(SAMPLE 1) exhibited high anodic potential values which isa clear reflection of high corrosion rate in the contaminatedconcrete Half cell potentials of steel specimen in SAMPLE 2were less negative (more cathodic) than SAMPLE 1 during the
International Journal of Corrosion 5
2
3
1
2 3
1
1 160 days
Sample 1
Sample 2
2 320 days3 480 days
1 160 days2 320 days3 480 days
00
05
10
15
20
25
30
minusZ
(o
hm cG
2)
15 20 25 3010Z
(ohm cG2)
0
5
10
15
20
25
30
35
40
minusZ
(o
hm cG
2)
60 180 100 120 140 160 180 200 22040Z
(ohm cG2)
(a)
2 3
3
1
21
Sample 1
Sample 2
1 160 days2 320 days3 480 days
1 160 days2 320 days3 480 days
12 14 16 18 20 22 24 26 28 301010log(frequency)Hz
0
200
400
600
800
1000
10lo
gZo
hm
0
200
400
600
800
1000
10lo
gZo
hm
60 180 100 120 140 160 180 2004010log(frequency)Hz
(b)
Figure 3 Nyquist plots and Bode plots of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480days
Rs
W
Cdl
Rct
Figure 4 Equivalent circuit fitted for EIS measurements of steelreinforcement in contaminated concrete
period of investigation These results show that SLS is actingas a good corrosion inhibitor on steel reinforcement throughthe period of investigation
34 Gravimetric Analysis Gravimetric analysis of steel rein-forcement in SAMPLE 1 and SAMPLE 2 was done forexamining the percentage of weight loss and the approximate
corrosion inhibition efficacy of SLS After the period ofinvestigation steel specimens were taken outside from theconcrete block pickled with HCl dried and weighed Steelreinforcements of SAMPLE 1 and SAMPLE 2 displayedweight losses of 24 and 36 respectively Thus the inter-vention of SLS on the steel rebar in concrete contaminatedwith NaCl was well established Approximate value of corro-sion inhibition efficiency of SLS determined by gravimetricstudies was 86
35 FT-IR Analysis IR spectral studies of the corroded prod-uct gave an idea about the nature of interaction of SLS on steelreinforcement Surface deposits were removed and subjectedto spectral analysis Various compounds such as ferrous andferric hydroxides hydrated ferric oxide and ferrous chloridemay be deposited on the steel reinforcement A broad signalobserved at 3375 cmminus1 in the spectrum of corroded productof SAMPLE 1 was due to ndashOH stretching frequency of ferroushydroxide or hydrated ferric oxide (or both) [35] In the IRspectrum of corroded product of SAMPLE 2 it was noticed
6 International Journal of Corrosion
Table3Halfcellp
otentia
l(mV)o
fsteelreinforcem
entinconcretein
thep
resencea
ndabsenceo
fSLS
for4
80days
Day
3060
90120
150
180
210
240
270
300
330
360
390
420
450
480
SAMPL
E1
-607
-588
-580
-555
-560
-554
-567
-578
-611
-592
-625
-628
-589
-602
-597
-600
SAMPL
E2
-416
-463
-420
-423
-514
-457
-497
-473
-440
-416
-499
-516
-535
-399
-397
-389
International Journal of Corrosion 7
Sample 1Sample 2
100 200 300 400 5000Days
minus650
minus600
minus550
minus500
minus450
minus400
Hal
f cel
l pot
entia
l
Figure 5 Variation of half cell potentials of steel reinforcement in contaminated concrete in the absence (SAMPLE 1) and presence (SAMPLE2) of SLS during 480 days
Corrosion product on steel rebar (sample 1)
3000 2000 1000 04000
3375
4411471
638
1619
868
1350
-1Wavenumber (cG )
minus50
0
50
100
150
200
250
300
350
400
T
rans
mitt
ance
(a)
3349
2895
28022347
16331420
1104955
789
2922
2821
16521466
1244
1067984
826
Corrosion product on steel (Sample 2)
4000 25003500 50020003000 10001500Wavenumber cG-1
minus10
0
10
20
30
40
50
60
70
80
90
100
110
T
rans
mitt
ance
SLS
2376
(b)
Figure 6 IR spectrum of oxide film deposited on the steel reinforcement in (a) SAMPLE 1 and (b) SAMPLE 2 and spectrum of SLS
that the peak due to ndashOH frequency shifted to 3349 cmminus1This may be due to the interaction of SLS with the ferrous orferric hydroxide The IR spectrum of sodium lauryl sulphatecontains peaks at 2922 and 2821 cmminus1 which can assignedto the stretching frequencies of various C-H This peak wasvisible at 2895 cmminus1 in the spectrum of surface productof SAMPLE 2 steel specimen In the IR spectrum of SLStwo IR regions corresponding to symmetric and asymmetricstretching frequency of sulphate group appeared at 826-1240cmminus1 and 1240-1466cmminus1 respectively These peaks wereshifted to 789-1104cmminus1 and 1104-1420cmminus1 in the spectrumof corroded product of SAMPLE 2 This is clear indication ofthe interaction of SLS through the sulphate end A weak peakcorresponding to the C-C stretching frequency of carbon
skeleton displayed at 964cmminus1 in the IR spectrum of SLSwas shifted to 955cmminus1 Two intense peaks at 2821cmminus1and 2922cmminus1 corresponding to symmetric and asymmetricstretching frequencies of CH
2groups of SLS also shifted to
2802cmminus1 and 2895cmminus1 in the FT-IR spectrum of surfacedeposits of steel in SAMLE 2 Figure 6 represents thespectrum of SLS and the IR spectrum of oxide film depositedon the steel reinforcement in SAMPLE 1and SAMPLE 2
36 Microscopic Surface Analysis Micrographs of bare steelrebar and steel reinforcements of SAMPLE 1 and SAMPLE 2after the investigation period are given in Figure 7 Surface ofsteel rebar in SAMPLE 1 contained large amount of hydratedferric oxide It is evident that enhanced corrosion of the
8 International Journal of Corrosion
(a) (b)
(c)
Figure 7 Optical micrographs of steel reinforcements (a) bare (b) in SAMPLE 1 and (c) in SAMPLE 2
steel rebar occurred due to the continuous contact of thecontaminated concrete pore solution It was noticed that thesurface of steel reinforcement in SAMPLE 2 contains littleor no oxide Thus the ability of SLS to prevent the steelreinforcement corrosion in contaminated concrete was onceagain proven by this analysis
37 Mechanism of Inhibition Sodium lauryl sulphate is asurfactant molecule and can performwell on the steel surfaceto decrease the rate of anodic and cathodic processes ofcorrosion [36 37] It can be assumed that SLS moleculespresent in concrete pore solution slowly migrate towards thesteel surface andmake coordinate bondswith the ferrous ionson the surface through the polar end Since SLS has a longhydrophobic chain pointing away from the steel surface itcan repel watermolecules and chloride ions diffusing towardsthe surface This process is really beneficial to control theelectrochemical process of corrosion In other words SLSefficiently resists the conversion of ferrous ions into hydratedferric oxide (rust) The overall mechanism of the inhibitionand the structure of SLS are represented in Figure 8
4 Conclusion
Investigations revealed that sodium lauryl sulphate has been apotent corrosion inhibitor for the steel reinforcement in con-taminated concrete for a long time Electrochemical studiesproved that the corrosion inhibition efficacy of SLS did notalter appreciably SLS generally affect the cathodic and anodicprocess of corrosion According to gravimetric studies SLSdisplayed 86 of corrosion inhibition efficiency on steelreinforcement in contaminated concrete These results arein good agreement with the electrochemical investigationresults FT-IR and microscopic surface analysis proved theinteraction of SLS on steel reinforcement
Data Availability
No data were used to support this study
Conflicts of Interest
The authors declare that they have no conflicts of interest
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
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Polymer ScienceInternational Journal of
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Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
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Hindawiwwwhindawicom Volume 2018
Na
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ria
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Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
2 International Journal of Corrosion
SS mesh
ElectrochemicalWorkstation
Rebar
Wet sponge
SCE
Figure 1 Three-electrode circuitry for electrochemical studies
in contaminated concrete [30 31] Preliminary examina-tions were done by measuring the electrode potentials ofsteel reinforcements (against SCE) dipped in concrete poresolution contaminated with 35 NaCl containing variousconcentrations of SLS After this examination we decidedto investigate the corrosion response of steel reinforcementin concrete specimen containing 25 of SLS by weight ofcement
2 Experimental
21 Materials Sodium lauryl sulphate and sodium chloride(gt999 ) were procured from Merck Millipore Portlandcement (Indiana Cements Grade 53) used for making con-crete specimens was purchased from the market
22 Preparation of Concrete Test Specimens Concrete blockscontaining steel reinforcement used for the experiment weremade of Portland cement coarse aggregate fine aggregate(sand) and water Each rectangular block having dimensionof 200x80x80mm was prepared by mixing water and cementin the ratio 05The ratio between cement fine aggregate andcoarse aggregate was 1153 which will exactly mimic M-20grade concrete SLS was added to the concrete mixture by25 wt of cement and two test specimens were casted Inthis work we designate the concrete specimen without SLSas SAMPLE 1 and with SLS as SAMPLE 2 The approximatecomposition of steel rod was estimated by EDAXmethod 01 P 062 Mn 0021 Si 004 S and rest Fe Steel rebarswere cut (22 cm) and immersed in 2M HCl for 10 minutesfor removing the rust washed with distilled water degreasedwith acetone dried weighed and used as the reinforcementin concrete After a period of 24 h the test specimens wereremoved from themould and cured for 30 days for the properhydration and setting of the cement
23 Treatment of Test Specimens After the curing periodfive sides of the test specimens were coated with epoxyresin and one open reservoir (100x40x20mm) was built onthe remaining side with polypropylene and silicon adhesive
25mL 35NaCl was added to the reservoir of the specimensand kept for 2 days This will ensure the complete diffusionof NaCl throughout the specimen This process was repeatedthree times during 30-60 days
24 Electrochemical Investigations
(i) Potentiodynamic Polarization Studies Figure 1 shows theschematic diagram of the test specimen and the experi-mental setup for electrochemical studies Three-electrodecell assembly consisting of steel reinforcement present inconcrete as working electrode concrete specimen coveredwith a stainless steel mesh as counter electrode and saturatedcalomel electrode (SCE) as reference electrode were used forthe electrochemical studies [32] For good electrical contacta wet sponge was used on the concrete surface between SCEand concrete surface
After curing and treatment of test specimens with NaClpolarization studies were performed three times during aperiod of 480 days in 160 daysrsquo interval Steel reinforcement inthe concrete was scanned for a potential range of +250 to -250mV having a scan rate of 1mVs Tafel curves were analyzedto get the slopes which are extrapolated to get the corrosioncurrent densities The corrosion inhibition efficiency of SLSwas determined using the following equation
120578pol =119868corr minus 119868
1015840
corr119868corr
X100 (1)
where Icorr and I1015840corr are corrosion current densities of steelreinforcement in test specimens in the absence and presenceof SLS respectively Experiments were repeated with theduplicate concrete block and the average values were taken
(ii) Electrochemical Impedance Spectroscopic (EIS) Studies EISexperiments were carried out at constant potential in thefrequency range of 1 KHz to 100 mHz with excitation signalof 10mV amplitude Analysis of the Nyquist curves using theequivalent circuit gave the charge transfer resistance (Rct)
International Journal of Corrosion 3
Table 1 Tafel data of steel reinforcement in concrete in the presence and absence of SLS for different periods
Time System Icorr ba -bc -Ecorr 120578pol (day) (120583Acm2) (mVdec) (mVdec) (mV)160 SAMPLE 1 161 496 159 651
SAMPLE 2 18 430 232 573 89320 SAMPLE 1 139 489 156 662
SAMPLE 2 41 469 229 520 71480 SAMPLE 1 107 373 215 551
SAMPLE 2 21 341 230 561 80
Using Rct values corrosion inhibition efficacy of SLS wasdetermined using the following equation
120578EIS =R1015840ct minus Rct
RctX100 (2)
where R1015840ct and Rct are the charge transfer resistance ofworking electrode with and without SLS respectively Polar-ization and EIS analyses were done using Ivium CompactStatelectrochemical work station (IviumSoft)
(iii) Half Cell Potential Measurements For understanding thecorrosion response of steel reinforcement in concrete halfcell potential measurements were carried out using saturatedcalomel electrode (SCE) and high impedance voltmeter (HPE2378A) In this electrochemical cell steel reinforcementand SCE were acted as anode and cathode respectively Thepotential of the steel rebar was obtained by deducting the cellpotential from the standard electrode potential of saturatedcalomel electrode Sixteen readings were taken with a regularinterval of 1 reading per month during 480 days
25 Gravimetric Method Before casting the concrete blockseach steel rebar was pickled with 2M HCl for 10 minuteswashed with water degreased with acetone dried andweighed The surface areas of all reinforcements were thesame (105cm2) After 480 days concrete blocks were brokenand the steel reinforcementswere taken outside pickled using2M HCl for 15 minutes to remove the adhered rust washedwith water dried and weighed From the weight loss of thesteel specimens approximate corrosion inhibition efficiencyof SLS was calculated by the following equation
120578 = 1199080 minus 1199081199080
times 100 (3)
where w0and w are the weight loss of steel rebars of SAMPLE
1 and SAMPLE 2
26 Spectroscopic Studies Fourier Transform Infrared (FT-IR) spectroscopic study of corroded product on the steelreinforcement was conducted using KBr pellet method Thespectrum was recorded in the range of 400-4000cmminus1 usingShimadzu IR Affinity-1 model FT-IR spectrophotometer
27 Microscopic Surface Analysis After 480 days of elec-trochemical investigation the steel specimens were taken
outside from the concrete and analyzed using a high-resolution optical microscope (Leica Stereo Microscope NoS8ACO) This study mainly aims to understand the surfacemodifications that occurred for steel specimen during theperiod of investigation
3 Results and Discussions
31 Potentiodynamic Polarization Studies The inhibition effi-cacy of SLS and site of corrosion inhibition on steel rein-forcement in the contaminated concrete wasmonitored usingpotentiodynamic polarization studies Analysis of polariza-tion curve gave Tafel slopes current densities and percentageof inhibition efficiency which are given in Table 1 Fromthe data it is understandable that the steel reinforcementin the concrete containing SLS was less corroded than rein-forcement in the SAMPLE 1 During 480 days three sets ofmeasurements were taken in 160 daysrsquo interval It was noticedthat SLS exhibited 89 corrosion inhibition efficiency on160th day of study On 320th and 480th days of investigationinhibition efficiency changed to 71 and 80 respectivelyFrom these results it can be assured that SLS can act asan efficient admixture which resists the steel reinforcementcorrosion in the contaminated concrete structures for a longtime SLS mainly acted on cathodic sites of corrosion up to23 rd period of investigation since the cathodic slopes of theTafel lines altered appreciably (Figure 2) But the corrosioninhibition response of SLS was changed into mixed type(affecting both anodic and cathodic sites) towards the end ofstudy
The gradation in the inhibition efficiency of SLS can beexplained with the help of following hypothesis The entireperiod of investigation can be divided into three stages firststage (0-160 days) second stage (161-320 days) and third stage(321-480 days) In the first stage SLS molecules adjacent tothe steel rebar make coordinate bonds with ferrous ions andprevent chloride ions and water molecules diffusing towardsthe steel surface considerably Thus during this period SLSprotects well the corrosion of reinforcement Towards theend of second stage (320 days) it was observed that the rateof corrosion slightly increased Since the rate of diffusion ofchloride ion is greater than that of SLS higher percentage ofchloride ions can be expected near the steel surface than thatof first stage The porous nature of the hydrated ferric oxidehelps to enter water molecules chloride and oxygen moretowards the steel surface Thus SLS showed less corrosion
4 International Journal of Corrosion
Sample 1
160 days320 days480 days
minus03minus05 minus04minus06 minus02minus08 minus07
Potential (V)
minus25
minus20
minus15
minus10
minus05
00
05
10
15
log
curr
ent d
ensit
y(Ac
m
)
(a)
Sample 2
160 days320 days480 days
minus07 minus06 minus05 minus04 minus03 minus02minus08
Potential(V)
minus35
minus30
minus25
minus20
minus15
minus10
minus05
00
05
10
log
curr
ent d
ensit
y(Ac
m
)
(b)
Figure 2 Tafel curves of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480 days
Table 2 EIS parameters of steel reinforcement in concrete in the presence and absence of inhibitor for different periods
Time Sample W Rs Cdl Rct 120578(day) (Ohmsqrt(Hz) (Ωcm2) (120583Fcmminus2) (Ωcm2)160 SAMPLE 1 274 785 110 119
SAMPLE 2 502 975 109 931 872320 SAMPLE 1 352 157 885 147
SAMPLE 2 927 459 42 665 78480 SAMPLE 1 323 223 273 243
SAMPLE 2 158 574 096 173 86
protection efficacy at this stage In the third stage (480 days)the rate of corrosion was seemed to decrease again (but not asthat much of first stage) During the end of this stage it can bebelieved thatmore andmore SLSmoleculesmigrated towardsthe steel surface from the bulk and make more coordinatebonds with ferrous ions and protect steel surface This led tohigher corrosion protection efficiency of SLS than in secondstage
32 EIS Measurements The corrosion response of steel rein-forcement in concrete in the presence and absence of SLS wasmonitored using electrochemical impedance spectroscopyand the corresponding Nyquist plots are represented inFigure 3 The corrosion behaviour of steel reinforcement wassignificantly differed in the presence and absence of inhibitorThe equivalent circuit fitted for EIS measurements (Figure 4)consists of solution resistance (Rs) which is connected inseries to double layer capacitance (C
1) and this combination
is connected in parallel to a series combination of Warburgresistance (W) and charge transfer resistance (Rct) [33 34]The EIS parameters of the test specimens are given in Table 2Impedance data show that addition of SLS leads to the
decrease in double-layer capacitance and increase of chargetransfer resistance This is due to the adsorption of SLSmolecules on the steel rebar SLS exhibited 872 corrosioninhibition efficiency on 160th day of investigation Inhibitionefficiencies changed to 78 and 86 respectively on the 320th
and 480th days of study
33 Half Cell Potential Measurements The probability ofcorrosion of steel reinforcement in concrete was visualizedwith the help of half cell potential measurements It wasestablished by the previous researchers that tendency ofcorrosion increases as the potential of the steel reinforcementchanges to more anodic side Half cell potentials (Vs SCE)of steel reinforcements in concrete blocks during 480 dayswere measured at a time interval of 30 days and are givenin Table 3 The half cell potential values are compared withthe help of a line graph and are represented in Figure 5Data show that the steel reinforcement in concrete block(SAMPLE 1) exhibited high anodic potential values which isa clear reflection of high corrosion rate in the contaminatedconcrete Half cell potentials of steel specimen in SAMPLE 2were less negative (more cathodic) than SAMPLE 1 during the
International Journal of Corrosion 5
2
3
1
2 3
1
1 160 days
Sample 1
Sample 2
2 320 days3 480 days
1 160 days2 320 days3 480 days
00
05
10
15
20
25
30
minusZ
(o
hm cG
2)
15 20 25 3010Z
(ohm cG2)
0
5
10
15
20
25
30
35
40
minusZ
(o
hm cG
2)
60 180 100 120 140 160 180 200 22040Z
(ohm cG2)
(a)
2 3
3
1
21
Sample 1
Sample 2
1 160 days2 320 days3 480 days
1 160 days2 320 days3 480 days
12 14 16 18 20 22 24 26 28 301010log(frequency)Hz
0
200
400
600
800
1000
10lo
gZo
hm
0
200
400
600
800
1000
10lo
gZo
hm
60 180 100 120 140 160 180 2004010log(frequency)Hz
(b)
Figure 3 Nyquist plots and Bode plots of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480days
Rs
W
Cdl
Rct
Figure 4 Equivalent circuit fitted for EIS measurements of steelreinforcement in contaminated concrete
period of investigation These results show that SLS is actingas a good corrosion inhibitor on steel reinforcement throughthe period of investigation
34 Gravimetric Analysis Gravimetric analysis of steel rein-forcement in SAMPLE 1 and SAMPLE 2 was done forexamining the percentage of weight loss and the approximate
corrosion inhibition efficacy of SLS After the period ofinvestigation steel specimens were taken outside from theconcrete block pickled with HCl dried and weighed Steelreinforcements of SAMPLE 1 and SAMPLE 2 displayedweight losses of 24 and 36 respectively Thus the inter-vention of SLS on the steel rebar in concrete contaminatedwith NaCl was well established Approximate value of corro-sion inhibition efficiency of SLS determined by gravimetricstudies was 86
35 FT-IR Analysis IR spectral studies of the corroded prod-uct gave an idea about the nature of interaction of SLS on steelreinforcement Surface deposits were removed and subjectedto spectral analysis Various compounds such as ferrous andferric hydroxides hydrated ferric oxide and ferrous chloridemay be deposited on the steel reinforcement A broad signalobserved at 3375 cmminus1 in the spectrum of corroded productof SAMPLE 1 was due to ndashOH stretching frequency of ferroushydroxide or hydrated ferric oxide (or both) [35] In the IRspectrum of corroded product of SAMPLE 2 it was noticed
6 International Journal of Corrosion
Table3Halfcellp
otentia
l(mV)o
fsteelreinforcem
entinconcretein
thep
resencea
ndabsenceo
fSLS
for4
80days
Day
3060
90120
150
180
210
240
270
300
330
360
390
420
450
480
SAMPL
E1
-607
-588
-580
-555
-560
-554
-567
-578
-611
-592
-625
-628
-589
-602
-597
-600
SAMPL
E2
-416
-463
-420
-423
-514
-457
-497
-473
-440
-416
-499
-516
-535
-399
-397
-389
International Journal of Corrosion 7
Sample 1Sample 2
100 200 300 400 5000Days
minus650
minus600
minus550
minus500
minus450
minus400
Hal
f cel
l pot
entia
l
Figure 5 Variation of half cell potentials of steel reinforcement in contaminated concrete in the absence (SAMPLE 1) and presence (SAMPLE2) of SLS during 480 days
Corrosion product on steel rebar (sample 1)
3000 2000 1000 04000
3375
4411471
638
1619
868
1350
-1Wavenumber (cG )
minus50
0
50
100
150
200
250
300
350
400
T
rans
mitt
ance
(a)
3349
2895
28022347
16331420
1104955
789
2922
2821
16521466
1244
1067984
826
Corrosion product on steel (Sample 2)
4000 25003500 50020003000 10001500Wavenumber cG-1
minus10
0
10
20
30
40
50
60
70
80
90
100
110
T
rans
mitt
ance
SLS
2376
(b)
Figure 6 IR spectrum of oxide film deposited on the steel reinforcement in (a) SAMPLE 1 and (b) SAMPLE 2 and spectrum of SLS
that the peak due to ndashOH frequency shifted to 3349 cmminus1This may be due to the interaction of SLS with the ferrous orferric hydroxide The IR spectrum of sodium lauryl sulphatecontains peaks at 2922 and 2821 cmminus1 which can assignedto the stretching frequencies of various C-H This peak wasvisible at 2895 cmminus1 in the spectrum of surface productof SAMPLE 2 steel specimen In the IR spectrum of SLStwo IR regions corresponding to symmetric and asymmetricstretching frequency of sulphate group appeared at 826-1240cmminus1 and 1240-1466cmminus1 respectively These peaks wereshifted to 789-1104cmminus1 and 1104-1420cmminus1 in the spectrumof corroded product of SAMPLE 2 This is clear indication ofthe interaction of SLS through the sulphate end A weak peakcorresponding to the C-C stretching frequency of carbon
skeleton displayed at 964cmminus1 in the IR spectrum of SLSwas shifted to 955cmminus1 Two intense peaks at 2821cmminus1and 2922cmminus1 corresponding to symmetric and asymmetricstretching frequencies of CH
2groups of SLS also shifted to
2802cmminus1 and 2895cmminus1 in the FT-IR spectrum of surfacedeposits of steel in SAMLE 2 Figure 6 represents thespectrum of SLS and the IR spectrum of oxide film depositedon the steel reinforcement in SAMPLE 1and SAMPLE 2
36 Microscopic Surface Analysis Micrographs of bare steelrebar and steel reinforcements of SAMPLE 1 and SAMPLE 2after the investigation period are given in Figure 7 Surface ofsteel rebar in SAMPLE 1 contained large amount of hydratedferric oxide It is evident that enhanced corrosion of the
8 International Journal of Corrosion
(a) (b)
(c)
Figure 7 Optical micrographs of steel reinforcements (a) bare (b) in SAMPLE 1 and (c) in SAMPLE 2
steel rebar occurred due to the continuous contact of thecontaminated concrete pore solution It was noticed that thesurface of steel reinforcement in SAMPLE 2 contains littleor no oxide Thus the ability of SLS to prevent the steelreinforcement corrosion in contaminated concrete was onceagain proven by this analysis
37 Mechanism of Inhibition Sodium lauryl sulphate is asurfactant molecule and can performwell on the steel surfaceto decrease the rate of anodic and cathodic processes ofcorrosion [36 37] It can be assumed that SLS moleculespresent in concrete pore solution slowly migrate towards thesteel surface andmake coordinate bondswith the ferrous ionson the surface through the polar end Since SLS has a longhydrophobic chain pointing away from the steel surface itcan repel watermolecules and chloride ions diffusing towardsthe surface This process is really beneficial to control theelectrochemical process of corrosion In other words SLSefficiently resists the conversion of ferrous ions into hydratedferric oxide (rust) The overall mechanism of the inhibitionand the structure of SLS are represented in Figure 8
4 Conclusion
Investigations revealed that sodium lauryl sulphate has been apotent corrosion inhibitor for the steel reinforcement in con-taminated concrete for a long time Electrochemical studiesproved that the corrosion inhibition efficacy of SLS did notalter appreciably SLS generally affect the cathodic and anodicprocess of corrosion According to gravimetric studies SLSdisplayed 86 of corrosion inhibition efficiency on steelreinforcement in contaminated concrete These results arein good agreement with the electrochemical investigationresults FT-IR and microscopic surface analysis proved theinteraction of SLS on steel reinforcement
Data Availability
No data were used to support this study
Conflicts of Interest
The authors declare that they have no conflicts of interest
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
International Journal of Corrosion 3
Table 1 Tafel data of steel reinforcement in concrete in the presence and absence of SLS for different periods
Time System Icorr ba -bc -Ecorr 120578pol (day) (120583Acm2) (mVdec) (mVdec) (mV)160 SAMPLE 1 161 496 159 651
SAMPLE 2 18 430 232 573 89320 SAMPLE 1 139 489 156 662
SAMPLE 2 41 469 229 520 71480 SAMPLE 1 107 373 215 551
SAMPLE 2 21 341 230 561 80
Using Rct values corrosion inhibition efficacy of SLS wasdetermined using the following equation
120578EIS =R1015840ct minus Rct
RctX100 (2)
where R1015840ct and Rct are the charge transfer resistance ofworking electrode with and without SLS respectively Polar-ization and EIS analyses were done using Ivium CompactStatelectrochemical work station (IviumSoft)
(iii) Half Cell Potential Measurements For understanding thecorrosion response of steel reinforcement in concrete halfcell potential measurements were carried out using saturatedcalomel electrode (SCE) and high impedance voltmeter (HPE2378A) In this electrochemical cell steel reinforcementand SCE were acted as anode and cathode respectively Thepotential of the steel rebar was obtained by deducting the cellpotential from the standard electrode potential of saturatedcalomel electrode Sixteen readings were taken with a regularinterval of 1 reading per month during 480 days
25 Gravimetric Method Before casting the concrete blockseach steel rebar was pickled with 2M HCl for 10 minuteswashed with water degreased with acetone dried andweighed The surface areas of all reinforcements were thesame (105cm2) After 480 days concrete blocks were brokenand the steel reinforcementswere taken outside pickled using2M HCl for 15 minutes to remove the adhered rust washedwith water dried and weighed From the weight loss of thesteel specimens approximate corrosion inhibition efficiencyof SLS was calculated by the following equation
120578 = 1199080 minus 1199081199080
times 100 (3)
where w0and w are the weight loss of steel rebars of SAMPLE
1 and SAMPLE 2
26 Spectroscopic Studies Fourier Transform Infrared (FT-IR) spectroscopic study of corroded product on the steelreinforcement was conducted using KBr pellet method Thespectrum was recorded in the range of 400-4000cmminus1 usingShimadzu IR Affinity-1 model FT-IR spectrophotometer
27 Microscopic Surface Analysis After 480 days of elec-trochemical investigation the steel specimens were taken
outside from the concrete and analyzed using a high-resolution optical microscope (Leica Stereo Microscope NoS8ACO) This study mainly aims to understand the surfacemodifications that occurred for steel specimen during theperiod of investigation
3 Results and Discussions
31 Potentiodynamic Polarization Studies The inhibition effi-cacy of SLS and site of corrosion inhibition on steel rein-forcement in the contaminated concrete wasmonitored usingpotentiodynamic polarization studies Analysis of polariza-tion curve gave Tafel slopes current densities and percentageof inhibition efficiency which are given in Table 1 Fromthe data it is understandable that the steel reinforcementin the concrete containing SLS was less corroded than rein-forcement in the SAMPLE 1 During 480 days three sets ofmeasurements were taken in 160 daysrsquo interval It was noticedthat SLS exhibited 89 corrosion inhibition efficiency on160th day of study On 320th and 480th days of investigationinhibition efficiency changed to 71 and 80 respectivelyFrom these results it can be assured that SLS can act asan efficient admixture which resists the steel reinforcementcorrosion in the contaminated concrete structures for a longtime SLS mainly acted on cathodic sites of corrosion up to23 rd period of investigation since the cathodic slopes of theTafel lines altered appreciably (Figure 2) But the corrosioninhibition response of SLS was changed into mixed type(affecting both anodic and cathodic sites) towards the end ofstudy
The gradation in the inhibition efficiency of SLS can beexplained with the help of following hypothesis The entireperiod of investigation can be divided into three stages firststage (0-160 days) second stage (161-320 days) and third stage(321-480 days) In the first stage SLS molecules adjacent tothe steel rebar make coordinate bonds with ferrous ions andprevent chloride ions and water molecules diffusing towardsthe steel surface considerably Thus during this period SLSprotects well the corrosion of reinforcement Towards theend of second stage (320 days) it was observed that the rateof corrosion slightly increased Since the rate of diffusion ofchloride ion is greater than that of SLS higher percentage ofchloride ions can be expected near the steel surface than thatof first stage The porous nature of the hydrated ferric oxidehelps to enter water molecules chloride and oxygen moretowards the steel surface Thus SLS showed less corrosion
4 International Journal of Corrosion
Sample 1
160 days320 days480 days
minus03minus05 minus04minus06 minus02minus08 minus07
Potential (V)
minus25
minus20
minus15
minus10
minus05
00
05
10
15
log
curr
ent d
ensit
y(Ac
m
)
(a)
Sample 2
160 days320 days480 days
minus07 minus06 minus05 minus04 minus03 minus02minus08
Potential(V)
minus35
minus30
minus25
minus20
minus15
minus10
minus05
00
05
10
log
curr
ent d
ensit
y(Ac
m
)
(b)
Figure 2 Tafel curves of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480 days
Table 2 EIS parameters of steel reinforcement in concrete in the presence and absence of inhibitor for different periods
Time Sample W Rs Cdl Rct 120578(day) (Ohmsqrt(Hz) (Ωcm2) (120583Fcmminus2) (Ωcm2)160 SAMPLE 1 274 785 110 119
SAMPLE 2 502 975 109 931 872320 SAMPLE 1 352 157 885 147
SAMPLE 2 927 459 42 665 78480 SAMPLE 1 323 223 273 243
SAMPLE 2 158 574 096 173 86
protection efficacy at this stage In the third stage (480 days)the rate of corrosion was seemed to decrease again (but not asthat much of first stage) During the end of this stage it can bebelieved thatmore andmore SLSmoleculesmigrated towardsthe steel surface from the bulk and make more coordinatebonds with ferrous ions and protect steel surface This led tohigher corrosion protection efficiency of SLS than in secondstage
32 EIS Measurements The corrosion response of steel rein-forcement in concrete in the presence and absence of SLS wasmonitored using electrochemical impedance spectroscopyand the corresponding Nyquist plots are represented inFigure 3 The corrosion behaviour of steel reinforcement wassignificantly differed in the presence and absence of inhibitorThe equivalent circuit fitted for EIS measurements (Figure 4)consists of solution resistance (Rs) which is connected inseries to double layer capacitance (C
1) and this combination
is connected in parallel to a series combination of Warburgresistance (W) and charge transfer resistance (Rct) [33 34]The EIS parameters of the test specimens are given in Table 2Impedance data show that addition of SLS leads to the
decrease in double-layer capacitance and increase of chargetransfer resistance This is due to the adsorption of SLSmolecules on the steel rebar SLS exhibited 872 corrosioninhibition efficiency on 160th day of investigation Inhibitionefficiencies changed to 78 and 86 respectively on the 320th
and 480th days of study
33 Half Cell Potential Measurements The probability ofcorrosion of steel reinforcement in concrete was visualizedwith the help of half cell potential measurements It wasestablished by the previous researchers that tendency ofcorrosion increases as the potential of the steel reinforcementchanges to more anodic side Half cell potentials (Vs SCE)of steel reinforcements in concrete blocks during 480 dayswere measured at a time interval of 30 days and are givenin Table 3 The half cell potential values are compared withthe help of a line graph and are represented in Figure 5Data show that the steel reinforcement in concrete block(SAMPLE 1) exhibited high anodic potential values which isa clear reflection of high corrosion rate in the contaminatedconcrete Half cell potentials of steel specimen in SAMPLE 2were less negative (more cathodic) than SAMPLE 1 during the
International Journal of Corrosion 5
2
3
1
2 3
1
1 160 days
Sample 1
Sample 2
2 320 days3 480 days
1 160 days2 320 days3 480 days
00
05
10
15
20
25
30
minusZ
(o
hm cG
2)
15 20 25 3010Z
(ohm cG2)
0
5
10
15
20
25
30
35
40
minusZ
(o
hm cG
2)
60 180 100 120 140 160 180 200 22040Z
(ohm cG2)
(a)
2 3
3
1
21
Sample 1
Sample 2
1 160 days2 320 days3 480 days
1 160 days2 320 days3 480 days
12 14 16 18 20 22 24 26 28 301010log(frequency)Hz
0
200
400
600
800
1000
10lo
gZo
hm
0
200
400
600
800
1000
10lo
gZo
hm
60 180 100 120 140 160 180 2004010log(frequency)Hz
(b)
Figure 3 Nyquist plots and Bode plots of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480days
Rs
W
Cdl
Rct
Figure 4 Equivalent circuit fitted for EIS measurements of steelreinforcement in contaminated concrete
period of investigation These results show that SLS is actingas a good corrosion inhibitor on steel reinforcement throughthe period of investigation
34 Gravimetric Analysis Gravimetric analysis of steel rein-forcement in SAMPLE 1 and SAMPLE 2 was done forexamining the percentage of weight loss and the approximate
corrosion inhibition efficacy of SLS After the period ofinvestigation steel specimens were taken outside from theconcrete block pickled with HCl dried and weighed Steelreinforcements of SAMPLE 1 and SAMPLE 2 displayedweight losses of 24 and 36 respectively Thus the inter-vention of SLS on the steel rebar in concrete contaminatedwith NaCl was well established Approximate value of corro-sion inhibition efficiency of SLS determined by gravimetricstudies was 86
35 FT-IR Analysis IR spectral studies of the corroded prod-uct gave an idea about the nature of interaction of SLS on steelreinforcement Surface deposits were removed and subjectedto spectral analysis Various compounds such as ferrous andferric hydroxides hydrated ferric oxide and ferrous chloridemay be deposited on the steel reinforcement A broad signalobserved at 3375 cmminus1 in the spectrum of corroded productof SAMPLE 1 was due to ndashOH stretching frequency of ferroushydroxide or hydrated ferric oxide (or both) [35] In the IRspectrum of corroded product of SAMPLE 2 it was noticed
6 International Journal of Corrosion
Table3Halfcellp
otentia
l(mV)o
fsteelreinforcem
entinconcretein
thep
resencea
ndabsenceo
fSLS
for4
80days
Day
3060
90120
150
180
210
240
270
300
330
360
390
420
450
480
SAMPL
E1
-607
-588
-580
-555
-560
-554
-567
-578
-611
-592
-625
-628
-589
-602
-597
-600
SAMPL
E2
-416
-463
-420
-423
-514
-457
-497
-473
-440
-416
-499
-516
-535
-399
-397
-389
International Journal of Corrosion 7
Sample 1Sample 2
100 200 300 400 5000Days
minus650
minus600
minus550
minus500
minus450
minus400
Hal
f cel
l pot
entia
l
Figure 5 Variation of half cell potentials of steel reinforcement in contaminated concrete in the absence (SAMPLE 1) and presence (SAMPLE2) of SLS during 480 days
Corrosion product on steel rebar (sample 1)
3000 2000 1000 04000
3375
4411471
638
1619
868
1350
-1Wavenumber (cG )
minus50
0
50
100
150
200
250
300
350
400
T
rans
mitt
ance
(a)
3349
2895
28022347
16331420
1104955
789
2922
2821
16521466
1244
1067984
826
Corrosion product on steel (Sample 2)
4000 25003500 50020003000 10001500Wavenumber cG-1
minus10
0
10
20
30
40
50
60
70
80
90
100
110
T
rans
mitt
ance
SLS
2376
(b)
Figure 6 IR spectrum of oxide film deposited on the steel reinforcement in (a) SAMPLE 1 and (b) SAMPLE 2 and spectrum of SLS
that the peak due to ndashOH frequency shifted to 3349 cmminus1This may be due to the interaction of SLS with the ferrous orferric hydroxide The IR spectrum of sodium lauryl sulphatecontains peaks at 2922 and 2821 cmminus1 which can assignedto the stretching frequencies of various C-H This peak wasvisible at 2895 cmminus1 in the spectrum of surface productof SAMPLE 2 steel specimen In the IR spectrum of SLStwo IR regions corresponding to symmetric and asymmetricstretching frequency of sulphate group appeared at 826-1240cmminus1 and 1240-1466cmminus1 respectively These peaks wereshifted to 789-1104cmminus1 and 1104-1420cmminus1 in the spectrumof corroded product of SAMPLE 2 This is clear indication ofthe interaction of SLS through the sulphate end A weak peakcorresponding to the C-C stretching frequency of carbon
skeleton displayed at 964cmminus1 in the IR spectrum of SLSwas shifted to 955cmminus1 Two intense peaks at 2821cmminus1and 2922cmminus1 corresponding to symmetric and asymmetricstretching frequencies of CH
2groups of SLS also shifted to
2802cmminus1 and 2895cmminus1 in the FT-IR spectrum of surfacedeposits of steel in SAMLE 2 Figure 6 represents thespectrum of SLS and the IR spectrum of oxide film depositedon the steel reinforcement in SAMPLE 1and SAMPLE 2
36 Microscopic Surface Analysis Micrographs of bare steelrebar and steel reinforcements of SAMPLE 1 and SAMPLE 2after the investigation period are given in Figure 7 Surface ofsteel rebar in SAMPLE 1 contained large amount of hydratedferric oxide It is evident that enhanced corrosion of the
8 International Journal of Corrosion
(a) (b)
(c)
Figure 7 Optical micrographs of steel reinforcements (a) bare (b) in SAMPLE 1 and (c) in SAMPLE 2
steel rebar occurred due to the continuous contact of thecontaminated concrete pore solution It was noticed that thesurface of steel reinforcement in SAMPLE 2 contains littleor no oxide Thus the ability of SLS to prevent the steelreinforcement corrosion in contaminated concrete was onceagain proven by this analysis
37 Mechanism of Inhibition Sodium lauryl sulphate is asurfactant molecule and can performwell on the steel surfaceto decrease the rate of anodic and cathodic processes ofcorrosion [36 37] It can be assumed that SLS moleculespresent in concrete pore solution slowly migrate towards thesteel surface andmake coordinate bondswith the ferrous ionson the surface through the polar end Since SLS has a longhydrophobic chain pointing away from the steel surface itcan repel watermolecules and chloride ions diffusing towardsthe surface This process is really beneficial to control theelectrochemical process of corrosion In other words SLSefficiently resists the conversion of ferrous ions into hydratedferric oxide (rust) The overall mechanism of the inhibitionand the structure of SLS are represented in Figure 8
4 Conclusion
Investigations revealed that sodium lauryl sulphate has been apotent corrosion inhibitor for the steel reinforcement in con-taminated concrete for a long time Electrochemical studiesproved that the corrosion inhibition efficacy of SLS did notalter appreciably SLS generally affect the cathodic and anodicprocess of corrosion According to gravimetric studies SLSdisplayed 86 of corrosion inhibition efficiency on steelreinforcement in contaminated concrete These results arein good agreement with the electrochemical investigationresults FT-IR and microscopic surface analysis proved theinteraction of SLS on steel reinforcement
Data Availability
No data were used to support this study
Conflicts of Interest
The authors declare that they have no conflicts of interest
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
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Analytical ChemistryInternational Journal of
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Submit your manuscripts atwwwhindawicom
4 International Journal of Corrosion
Sample 1
160 days320 days480 days
minus03minus05 minus04minus06 minus02minus08 minus07
Potential (V)
minus25
minus20
minus15
minus10
minus05
00
05
10
15
log
curr
ent d
ensit
y(Ac
m
)
(a)
Sample 2
160 days320 days480 days
minus07 minus06 minus05 minus04 minus03 minus02minus08
Potential(V)
minus35
minus30
minus25
minus20
minus15
minus10
minus05
00
05
10
log
curr
ent d
ensit
y(Ac
m
)
(b)
Figure 2 Tafel curves of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480 days
Table 2 EIS parameters of steel reinforcement in concrete in the presence and absence of inhibitor for different periods
Time Sample W Rs Cdl Rct 120578(day) (Ohmsqrt(Hz) (Ωcm2) (120583Fcmminus2) (Ωcm2)160 SAMPLE 1 274 785 110 119
SAMPLE 2 502 975 109 931 872320 SAMPLE 1 352 157 885 147
SAMPLE 2 927 459 42 665 78480 SAMPLE 1 323 223 273 243
SAMPLE 2 158 574 096 173 86
protection efficacy at this stage In the third stage (480 days)the rate of corrosion was seemed to decrease again (but not asthat much of first stage) During the end of this stage it can bebelieved thatmore andmore SLSmoleculesmigrated towardsthe steel surface from the bulk and make more coordinatebonds with ferrous ions and protect steel surface This led tohigher corrosion protection efficiency of SLS than in secondstage
32 EIS Measurements The corrosion response of steel rein-forcement in concrete in the presence and absence of SLS wasmonitored using electrochemical impedance spectroscopyand the corresponding Nyquist plots are represented inFigure 3 The corrosion behaviour of steel reinforcement wassignificantly differed in the presence and absence of inhibitorThe equivalent circuit fitted for EIS measurements (Figure 4)consists of solution resistance (Rs) which is connected inseries to double layer capacitance (C
1) and this combination
is connected in parallel to a series combination of Warburgresistance (W) and charge transfer resistance (Rct) [33 34]The EIS parameters of the test specimens are given in Table 2Impedance data show that addition of SLS leads to the
decrease in double-layer capacitance and increase of chargetransfer resistance This is due to the adsorption of SLSmolecules on the steel rebar SLS exhibited 872 corrosioninhibition efficiency on 160th day of investigation Inhibitionefficiencies changed to 78 and 86 respectively on the 320th
and 480th days of study
33 Half Cell Potential Measurements The probability ofcorrosion of steel reinforcement in concrete was visualizedwith the help of half cell potential measurements It wasestablished by the previous researchers that tendency ofcorrosion increases as the potential of the steel reinforcementchanges to more anodic side Half cell potentials (Vs SCE)of steel reinforcements in concrete blocks during 480 dayswere measured at a time interval of 30 days and are givenin Table 3 The half cell potential values are compared withthe help of a line graph and are represented in Figure 5Data show that the steel reinforcement in concrete block(SAMPLE 1) exhibited high anodic potential values which isa clear reflection of high corrosion rate in the contaminatedconcrete Half cell potentials of steel specimen in SAMPLE 2were less negative (more cathodic) than SAMPLE 1 during the
International Journal of Corrosion 5
2
3
1
2 3
1
1 160 days
Sample 1
Sample 2
2 320 days3 480 days
1 160 days2 320 days3 480 days
00
05
10
15
20
25
30
minusZ
(o
hm cG
2)
15 20 25 3010Z
(ohm cG2)
0
5
10
15
20
25
30
35
40
minusZ
(o
hm cG
2)
60 180 100 120 140 160 180 200 22040Z
(ohm cG2)
(a)
2 3
3
1
21
Sample 1
Sample 2
1 160 days2 320 days3 480 days
1 160 days2 320 days3 480 days
12 14 16 18 20 22 24 26 28 301010log(frequency)Hz
0
200
400
600
800
1000
10lo
gZo
hm
0
200
400
600
800
1000
10lo
gZo
hm
60 180 100 120 140 160 180 2004010log(frequency)Hz
(b)
Figure 3 Nyquist plots and Bode plots of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480days
Rs
W
Cdl
Rct
Figure 4 Equivalent circuit fitted for EIS measurements of steelreinforcement in contaminated concrete
period of investigation These results show that SLS is actingas a good corrosion inhibitor on steel reinforcement throughthe period of investigation
34 Gravimetric Analysis Gravimetric analysis of steel rein-forcement in SAMPLE 1 and SAMPLE 2 was done forexamining the percentage of weight loss and the approximate
corrosion inhibition efficacy of SLS After the period ofinvestigation steel specimens were taken outside from theconcrete block pickled with HCl dried and weighed Steelreinforcements of SAMPLE 1 and SAMPLE 2 displayedweight losses of 24 and 36 respectively Thus the inter-vention of SLS on the steel rebar in concrete contaminatedwith NaCl was well established Approximate value of corro-sion inhibition efficiency of SLS determined by gravimetricstudies was 86
35 FT-IR Analysis IR spectral studies of the corroded prod-uct gave an idea about the nature of interaction of SLS on steelreinforcement Surface deposits were removed and subjectedto spectral analysis Various compounds such as ferrous andferric hydroxides hydrated ferric oxide and ferrous chloridemay be deposited on the steel reinforcement A broad signalobserved at 3375 cmminus1 in the spectrum of corroded productof SAMPLE 1 was due to ndashOH stretching frequency of ferroushydroxide or hydrated ferric oxide (or both) [35] In the IRspectrum of corroded product of SAMPLE 2 it was noticed
6 International Journal of Corrosion
Table3Halfcellp
otentia
l(mV)o
fsteelreinforcem
entinconcretein
thep
resencea
ndabsenceo
fSLS
for4
80days
Day
3060
90120
150
180
210
240
270
300
330
360
390
420
450
480
SAMPL
E1
-607
-588
-580
-555
-560
-554
-567
-578
-611
-592
-625
-628
-589
-602
-597
-600
SAMPL
E2
-416
-463
-420
-423
-514
-457
-497
-473
-440
-416
-499
-516
-535
-399
-397
-389
International Journal of Corrosion 7
Sample 1Sample 2
100 200 300 400 5000Days
minus650
minus600
minus550
minus500
minus450
minus400
Hal
f cel
l pot
entia
l
Figure 5 Variation of half cell potentials of steel reinforcement in contaminated concrete in the absence (SAMPLE 1) and presence (SAMPLE2) of SLS during 480 days
Corrosion product on steel rebar (sample 1)
3000 2000 1000 04000
3375
4411471
638
1619
868
1350
-1Wavenumber (cG )
minus50
0
50
100
150
200
250
300
350
400
T
rans
mitt
ance
(a)
3349
2895
28022347
16331420
1104955
789
2922
2821
16521466
1244
1067984
826
Corrosion product on steel (Sample 2)
4000 25003500 50020003000 10001500Wavenumber cG-1
minus10
0
10
20
30
40
50
60
70
80
90
100
110
T
rans
mitt
ance
SLS
2376
(b)
Figure 6 IR spectrum of oxide film deposited on the steel reinforcement in (a) SAMPLE 1 and (b) SAMPLE 2 and spectrum of SLS
that the peak due to ndashOH frequency shifted to 3349 cmminus1This may be due to the interaction of SLS with the ferrous orferric hydroxide The IR spectrum of sodium lauryl sulphatecontains peaks at 2922 and 2821 cmminus1 which can assignedto the stretching frequencies of various C-H This peak wasvisible at 2895 cmminus1 in the spectrum of surface productof SAMPLE 2 steel specimen In the IR spectrum of SLStwo IR regions corresponding to symmetric and asymmetricstretching frequency of sulphate group appeared at 826-1240cmminus1 and 1240-1466cmminus1 respectively These peaks wereshifted to 789-1104cmminus1 and 1104-1420cmminus1 in the spectrumof corroded product of SAMPLE 2 This is clear indication ofthe interaction of SLS through the sulphate end A weak peakcorresponding to the C-C stretching frequency of carbon
skeleton displayed at 964cmminus1 in the IR spectrum of SLSwas shifted to 955cmminus1 Two intense peaks at 2821cmminus1and 2922cmminus1 corresponding to symmetric and asymmetricstretching frequencies of CH
2groups of SLS also shifted to
2802cmminus1 and 2895cmminus1 in the FT-IR spectrum of surfacedeposits of steel in SAMLE 2 Figure 6 represents thespectrum of SLS and the IR spectrum of oxide film depositedon the steel reinforcement in SAMPLE 1and SAMPLE 2
36 Microscopic Surface Analysis Micrographs of bare steelrebar and steel reinforcements of SAMPLE 1 and SAMPLE 2after the investigation period are given in Figure 7 Surface ofsteel rebar in SAMPLE 1 contained large amount of hydratedferric oxide It is evident that enhanced corrosion of the
8 International Journal of Corrosion
(a) (b)
(c)
Figure 7 Optical micrographs of steel reinforcements (a) bare (b) in SAMPLE 1 and (c) in SAMPLE 2
steel rebar occurred due to the continuous contact of thecontaminated concrete pore solution It was noticed that thesurface of steel reinforcement in SAMPLE 2 contains littleor no oxide Thus the ability of SLS to prevent the steelreinforcement corrosion in contaminated concrete was onceagain proven by this analysis
37 Mechanism of Inhibition Sodium lauryl sulphate is asurfactant molecule and can performwell on the steel surfaceto decrease the rate of anodic and cathodic processes ofcorrosion [36 37] It can be assumed that SLS moleculespresent in concrete pore solution slowly migrate towards thesteel surface andmake coordinate bondswith the ferrous ionson the surface through the polar end Since SLS has a longhydrophobic chain pointing away from the steel surface itcan repel watermolecules and chloride ions diffusing towardsthe surface This process is really beneficial to control theelectrochemical process of corrosion In other words SLSefficiently resists the conversion of ferrous ions into hydratedferric oxide (rust) The overall mechanism of the inhibitionand the structure of SLS are represented in Figure 8
4 Conclusion
Investigations revealed that sodium lauryl sulphate has been apotent corrosion inhibitor for the steel reinforcement in con-taminated concrete for a long time Electrochemical studiesproved that the corrosion inhibition efficacy of SLS did notalter appreciably SLS generally affect the cathodic and anodicprocess of corrosion According to gravimetric studies SLSdisplayed 86 of corrosion inhibition efficiency on steelreinforcement in contaminated concrete These results arein good agreement with the electrochemical investigationresults FT-IR and microscopic surface analysis proved theinteraction of SLS on steel reinforcement
Data Availability
No data were used to support this study
Conflicts of Interest
The authors declare that they have no conflicts of interest
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
International Journal of Corrosion 5
2
3
1
2 3
1
1 160 days
Sample 1
Sample 2
2 320 days3 480 days
1 160 days2 320 days3 480 days
00
05
10
15
20
25
30
minusZ
(o
hm cG
2)
15 20 25 3010Z
(ohm cG2)
0
5
10
15
20
25
30
35
40
minusZ
(o
hm cG
2)
60 180 100 120 140 160 180 200 22040Z
(ohm cG2)
(a)
2 3
3
1
21
Sample 1
Sample 2
1 160 days2 320 days3 480 days
1 160 days2 320 days3 480 days
12 14 16 18 20 22 24 26 28 301010log(frequency)Hz
0
200
400
600
800
1000
10lo
gZo
hm
0
200
400
600
800
1000
10lo
gZo
hm
60 180 100 120 140 160 180 2004010log(frequency)Hz
(b)
Figure 3 Nyquist plots and Bode plots of steel reinforcement in concrete (a) in the absence and (b) presence of SLS for 160 320 and 480days
Rs
W
Cdl
Rct
Figure 4 Equivalent circuit fitted for EIS measurements of steelreinforcement in contaminated concrete
period of investigation These results show that SLS is actingas a good corrosion inhibitor on steel reinforcement throughthe period of investigation
34 Gravimetric Analysis Gravimetric analysis of steel rein-forcement in SAMPLE 1 and SAMPLE 2 was done forexamining the percentage of weight loss and the approximate
corrosion inhibition efficacy of SLS After the period ofinvestigation steel specimens were taken outside from theconcrete block pickled with HCl dried and weighed Steelreinforcements of SAMPLE 1 and SAMPLE 2 displayedweight losses of 24 and 36 respectively Thus the inter-vention of SLS on the steel rebar in concrete contaminatedwith NaCl was well established Approximate value of corro-sion inhibition efficiency of SLS determined by gravimetricstudies was 86
35 FT-IR Analysis IR spectral studies of the corroded prod-uct gave an idea about the nature of interaction of SLS on steelreinforcement Surface deposits were removed and subjectedto spectral analysis Various compounds such as ferrous andferric hydroxides hydrated ferric oxide and ferrous chloridemay be deposited on the steel reinforcement A broad signalobserved at 3375 cmminus1 in the spectrum of corroded productof SAMPLE 1 was due to ndashOH stretching frequency of ferroushydroxide or hydrated ferric oxide (or both) [35] In the IRspectrum of corroded product of SAMPLE 2 it was noticed
6 International Journal of Corrosion
Table3Halfcellp
otentia
l(mV)o
fsteelreinforcem
entinconcretein
thep
resencea
ndabsenceo
fSLS
for4
80days
Day
3060
90120
150
180
210
240
270
300
330
360
390
420
450
480
SAMPL
E1
-607
-588
-580
-555
-560
-554
-567
-578
-611
-592
-625
-628
-589
-602
-597
-600
SAMPL
E2
-416
-463
-420
-423
-514
-457
-497
-473
-440
-416
-499
-516
-535
-399
-397
-389
International Journal of Corrosion 7
Sample 1Sample 2
100 200 300 400 5000Days
minus650
minus600
minus550
minus500
minus450
minus400
Hal
f cel
l pot
entia
l
Figure 5 Variation of half cell potentials of steel reinforcement in contaminated concrete in the absence (SAMPLE 1) and presence (SAMPLE2) of SLS during 480 days
Corrosion product on steel rebar (sample 1)
3000 2000 1000 04000
3375
4411471
638
1619
868
1350
-1Wavenumber (cG )
minus50
0
50
100
150
200
250
300
350
400
T
rans
mitt
ance
(a)
3349
2895
28022347
16331420
1104955
789
2922
2821
16521466
1244
1067984
826
Corrosion product on steel (Sample 2)
4000 25003500 50020003000 10001500Wavenumber cG-1
minus10
0
10
20
30
40
50
60
70
80
90
100
110
T
rans
mitt
ance
SLS
2376
(b)
Figure 6 IR spectrum of oxide film deposited on the steel reinforcement in (a) SAMPLE 1 and (b) SAMPLE 2 and spectrum of SLS
that the peak due to ndashOH frequency shifted to 3349 cmminus1This may be due to the interaction of SLS with the ferrous orferric hydroxide The IR spectrum of sodium lauryl sulphatecontains peaks at 2922 and 2821 cmminus1 which can assignedto the stretching frequencies of various C-H This peak wasvisible at 2895 cmminus1 in the spectrum of surface productof SAMPLE 2 steel specimen In the IR spectrum of SLStwo IR regions corresponding to symmetric and asymmetricstretching frequency of sulphate group appeared at 826-1240cmminus1 and 1240-1466cmminus1 respectively These peaks wereshifted to 789-1104cmminus1 and 1104-1420cmminus1 in the spectrumof corroded product of SAMPLE 2 This is clear indication ofthe interaction of SLS through the sulphate end A weak peakcorresponding to the C-C stretching frequency of carbon
skeleton displayed at 964cmminus1 in the IR spectrum of SLSwas shifted to 955cmminus1 Two intense peaks at 2821cmminus1and 2922cmminus1 corresponding to symmetric and asymmetricstretching frequencies of CH
2groups of SLS also shifted to
2802cmminus1 and 2895cmminus1 in the FT-IR spectrum of surfacedeposits of steel in SAMLE 2 Figure 6 represents thespectrum of SLS and the IR spectrum of oxide film depositedon the steel reinforcement in SAMPLE 1and SAMPLE 2
36 Microscopic Surface Analysis Micrographs of bare steelrebar and steel reinforcements of SAMPLE 1 and SAMPLE 2after the investigation period are given in Figure 7 Surface ofsteel rebar in SAMPLE 1 contained large amount of hydratedferric oxide It is evident that enhanced corrosion of the
8 International Journal of Corrosion
(a) (b)
(c)
Figure 7 Optical micrographs of steel reinforcements (a) bare (b) in SAMPLE 1 and (c) in SAMPLE 2
steel rebar occurred due to the continuous contact of thecontaminated concrete pore solution It was noticed that thesurface of steel reinforcement in SAMPLE 2 contains littleor no oxide Thus the ability of SLS to prevent the steelreinforcement corrosion in contaminated concrete was onceagain proven by this analysis
37 Mechanism of Inhibition Sodium lauryl sulphate is asurfactant molecule and can performwell on the steel surfaceto decrease the rate of anodic and cathodic processes ofcorrosion [36 37] It can be assumed that SLS moleculespresent in concrete pore solution slowly migrate towards thesteel surface andmake coordinate bondswith the ferrous ionson the surface through the polar end Since SLS has a longhydrophobic chain pointing away from the steel surface itcan repel watermolecules and chloride ions diffusing towardsthe surface This process is really beneficial to control theelectrochemical process of corrosion In other words SLSefficiently resists the conversion of ferrous ions into hydratedferric oxide (rust) The overall mechanism of the inhibitionand the structure of SLS are represented in Figure 8
4 Conclusion
Investigations revealed that sodium lauryl sulphate has been apotent corrosion inhibitor for the steel reinforcement in con-taminated concrete for a long time Electrochemical studiesproved that the corrosion inhibition efficacy of SLS did notalter appreciably SLS generally affect the cathodic and anodicprocess of corrosion According to gravimetric studies SLSdisplayed 86 of corrosion inhibition efficiency on steelreinforcement in contaminated concrete These results arein good agreement with the electrochemical investigationresults FT-IR and microscopic surface analysis proved theinteraction of SLS on steel reinforcement
Data Availability
No data were used to support this study
Conflicts of Interest
The authors declare that they have no conflicts of interest
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
6 International Journal of Corrosion
Table3Halfcellp
otentia
l(mV)o
fsteelreinforcem
entinconcretein
thep
resencea
ndabsenceo
fSLS
for4
80days
Day
3060
90120
150
180
210
240
270
300
330
360
390
420
450
480
SAMPL
E1
-607
-588
-580
-555
-560
-554
-567
-578
-611
-592
-625
-628
-589
-602
-597
-600
SAMPL
E2
-416
-463
-420
-423
-514
-457
-497
-473
-440
-416
-499
-516
-535
-399
-397
-389
International Journal of Corrosion 7
Sample 1Sample 2
100 200 300 400 5000Days
minus650
minus600
minus550
minus500
minus450
minus400
Hal
f cel
l pot
entia
l
Figure 5 Variation of half cell potentials of steel reinforcement in contaminated concrete in the absence (SAMPLE 1) and presence (SAMPLE2) of SLS during 480 days
Corrosion product on steel rebar (sample 1)
3000 2000 1000 04000
3375
4411471
638
1619
868
1350
-1Wavenumber (cG )
minus50
0
50
100
150
200
250
300
350
400
T
rans
mitt
ance
(a)
3349
2895
28022347
16331420
1104955
789
2922
2821
16521466
1244
1067984
826
Corrosion product on steel (Sample 2)
4000 25003500 50020003000 10001500Wavenumber cG-1
minus10
0
10
20
30
40
50
60
70
80
90
100
110
T
rans
mitt
ance
SLS
2376
(b)
Figure 6 IR spectrum of oxide film deposited on the steel reinforcement in (a) SAMPLE 1 and (b) SAMPLE 2 and spectrum of SLS
that the peak due to ndashOH frequency shifted to 3349 cmminus1This may be due to the interaction of SLS with the ferrous orferric hydroxide The IR spectrum of sodium lauryl sulphatecontains peaks at 2922 and 2821 cmminus1 which can assignedto the stretching frequencies of various C-H This peak wasvisible at 2895 cmminus1 in the spectrum of surface productof SAMPLE 2 steel specimen In the IR spectrum of SLStwo IR regions corresponding to symmetric and asymmetricstretching frequency of sulphate group appeared at 826-1240cmminus1 and 1240-1466cmminus1 respectively These peaks wereshifted to 789-1104cmminus1 and 1104-1420cmminus1 in the spectrumof corroded product of SAMPLE 2 This is clear indication ofthe interaction of SLS through the sulphate end A weak peakcorresponding to the C-C stretching frequency of carbon
skeleton displayed at 964cmminus1 in the IR spectrum of SLSwas shifted to 955cmminus1 Two intense peaks at 2821cmminus1and 2922cmminus1 corresponding to symmetric and asymmetricstretching frequencies of CH
2groups of SLS also shifted to
2802cmminus1 and 2895cmminus1 in the FT-IR spectrum of surfacedeposits of steel in SAMLE 2 Figure 6 represents thespectrum of SLS and the IR spectrum of oxide film depositedon the steel reinforcement in SAMPLE 1and SAMPLE 2
36 Microscopic Surface Analysis Micrographs of bare steelrebar and steel reinforcements of SAMPLE 1 and SAMPLE 2after the investigation period are given in Figure 7 Surface ofsteel rebar in SAMPLE 1 contained large amount of hydratedferric oxide It is evident that enhanced corrosion of the
8 International Journal of Corrosion
(a) (b)
(c)
Figure 7 Optical micrographs of steel reinforcements (a) bare (b) in SAMPLE 1 and (c) in SAMPLE 2
steel rebar occurred due to the continuous contact of thecontaminated concrete pore solution It was noticed that thesurface of steel reinforcement in SAMPLE 2 contains littleor no oxide Thus the ability of SLS to prevent the steelreinforcement corrosion in contaminated concrete was onceagain proven by this analysis
37 Mechanism of Inhibition Sodium lauryl sulphate is asurfactant molecule and can performwell on the steel surfaceto decrease the rate of anodic and cathodic processes ofcorrosion [36 37] It can be assumed that SLS moleculespresent in concrete pore solution slowly migrate towards thesteel surface andmake coordinate bondswith the ferrous ionson the surface through the polar end Since SLS has a longhydrophobic chain pointing away from the steel surface itcan repel watermolecules and chloride ions diffusing towardsthe surface This process is really beneficial to control theelectrochemical process of corrosion In other words SLSefficiently resists the conversion of ferrous ions into hydratedferric oxide (rust) The overall mechanism of the inhibitionand the structure of SLS are represented in Figure 8
4 Conclusion
Investigations revealed that sodium lauryl sulphate has been apotent corrosion inhibitor for the steel reinforcement in con-taminated concrete for a long time Electrochemical studiesproved that the corrosion inhibition efficacy of SLS did notalter appreciably SLS generally affect the cathodic and anodicprocess of corrosion According to gravimetric studies SLSdisplayed 86 of corrosion inhibition efficiency on steelreinforcement in contaminated concrete These results arein good agreement with the electrochemical investigationresults FT-IR and microscopic surface analysis proved theinteraction of SLS on steel reinforcement
Data Availability
No data were used to support this study
Conflicts of Interest
The authors declare that they have no conflicts of interest
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
International Journal of Corrosion 7
Sample 1Sample 2
100 200 300 400 5000Days
minus650
minus600
minus550
minus500
minus450
minus400
Hal
f cel
l pot
entia
l
Figure 5 Variation of half cell potentials of steel reinforcement in contaminated concrete in the absence (SAMPLE 1) and presence (SAMPLE2) of SLS during 480 days
Corrosion product on steel rebar (sample 1)
3000 2000 1000 04000
3375
4411471
638
1619
868
1350
-1Wavenumber (cG )
minus50
0
50
100
150
200
250
300
350
400
T
rans
mitt
ance
(a)
3349
2895
28022347
16331420
1104955
789
2922
2821
16521466
1244
1067984
826
Corrosion product on steel (Sample 2)
4000 25003500 50020003000 10001500Wavenumber cG-1
minus10
0
10
20
30
40
50
60
70
80
90
100
110
T
rans
mitt
ance
SLS
2376
(b)
Figure 6 IR spectrum of oxide film deposited on the steel reinforcement in (a) SAMPLE 1 and (b) SAMPLE 2 and spectrum of SLS
that the peak due to ndashOH frequency shifted to 3349 cmminus1This may be due to the interaction of SLS with the ferrous orferric hydroxide The IR spectrum of sodium lauryl sulphatecontains peaks at 2922 and 2821 cmminus1 which can assignedto the stretching frequencies of various C-H This peak wasvisible at 2895 cmminus1 in the spectrum of surface productof SAMPLE 2 steel specimen In the IR spectrum of SLStwo IR regions corresponding to symmetric and asymmetricstretching frequency of sulphate group appeared at 826-1240cmminus1 and 1240-1466cmminus1 respectively These peaks wereshifted to 789-1104cmminus1 and 1104-1420cmminus1 in the spectrumof corroded product of SAMPLE 2 This is clear indication ofthe interaction of SLS through the sulphate end A weak peakcorresponding to the C-C stretching frequency of carbon
skeleton displayed at 964cmminus1 in the IR spectrum of SLSwas shifted to 955cmminus1 Two intense peaks at 2821cmminus1and 2922cmminus1 corresponding to symmetric and asymmetricstretching frequencies of CH
2groups of SLS also shifted to
2802cmminus1 and 2895cmminus1 in the FT-IR spectrum of surfacedeposits of steel in SAMLE 2 Figure 6 represents thespectrum of SLS and the IR spectrum of oxide film depositedon the steel reinforcement in SAMPLE 1and SAMPLE 2
36 Microscopic Surface Analysis Micrographs of bare steelrebar and steel reinforcements of SAMPLE 1 and SAMPLE 2after the investigation period are given in Figure 7 Surface ofsteel rebar in SAMPLE 1 contained large amount of hydratedferric oxide It is evident that enhanced corrosion of the
8 International Journal of Corrosion
(a) (b)
(c)
Figure 7 Optical micrographs of steel reinforcements (a) bare (b) in SAMPLE 1 and (c) in SAMPLE 2
steel rebar occurred due to the continuous contact of thecontaminated concrete pore solution It was noticed that thesurface of steel reinforcement in SAMPLE 2 contains littleor no oxide Thus the ability of SLS to prevent the steelreinforcement corrosion in contaminated concrete was onceagain proven by this analysis
37 Mechanism of Inhibition Sodium lauryl sulphate is asurfactant molecule and can performwell on the steel surfaceto decrease the rate of anodic and cathodic processes ofcorrosion [36 37] It can be assumed that SLS moleculespresent in concrete pore solution slowly migrate towards thesteel surface andmake coordinate bondswith the ferrous ionson the surface through the polar end Since SLS has a longhydrophobic chain pointing away from the steel surface itcan repel watermolecules and chloride ions diffusing towardsthe surface This process is really beneficial to control theelectrochemical process of corrosion In other words SLSefficiently resists the conversion of ferrous ions into hydratedferric oxide (rust) The overall mechanism of the inhibitionand the structure of SLS are represented in Figure 8
4 Conclusion
Investigations revealed that sodium lauryl sulphate has been apotent corrosion inhibitor for the steel reinforcement in con-taminated concrete for a long time Electrochemical studiesproved that the corrosion inhibition efficacy of SLS did notalter appreciably SLS generally affect the cathodic and anodicprocess of corrosion According to gravimetric studies SLSdisplayed 86 of corrosion inhibition efficiency on steelreinforcement in contaminated concrete These results arein good agreement with the electrochemical investigationresults FT-IR and microscopic surface analysis proved theinteraction of SLS on steel reinforcement
Data Availability
No data were used to support this study
Conflicts of Interest
The authors declare that they have no conflicts of interest
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
8 International Journal of Corrosion
(a) (b)
(c)
Figure 7 Optical micrographs of steel reinforcements (a) bare (b) in SAMPLE 1 and (c) in SAMPLE 2
steel rebar occurred due to the continuous contact of thecontaminated concrete pore solution It was noticed that thesurface of steel reinforcement in SAMPLE 2 contains littleor no oxide Thus the ability of SLS to prevent the steelreinforcement corrosion in contaminated concrete was onceagain proven by this analysis
37 Mechanism of Inhibition Sodium lauryl sulphate is asurfactant molecule and can performwell on the steel surfaceto decrease the rate of anodic and cathodic processes ofcorrosion [36 37] It can be assumed that SLS moleculespresent in concrete pore solution slowly migrate towards thesteel surface andmake coordinate bondswith the ferrous ionson the surface through the polar end Since SLS has a longhydrophobic chain pointing away from the steel surface itcan repel watermolecules and chloride ions diffusing towardsthe surface This process is really beneficial to control theelectrochemical process of corrosion In other words SLSefficiently resists the conversion of ferrous ions into hydratedferric oxide (rust) The overall mechanism of the inhibitionand the structure of SLS are represented in Figure 8
4 Conclusion
Investigations revealed that sodium lauryl sulphate has been apotent corrosion inhibitor for the steel reinforcement in con-taminated concrete for a long time Electrochemical studiesproved that the corrosion inhibition efficacy of SLS did notalter appreciably SLS generally affect the cathodic and anodicprocess of corrosion According to gravimetric studies SLSdisplayed 86 of corrosion inhibition efficiency on steelreinforcement in contaminated concrete These results arein good agreement with the electrochemical investigationresults FT-IR and microscopic surface analysis proved theinteraction of SLS on steel reinforcement
Data Availability
No data were used to support this study
Conflicts of Interest
The authors declare that they have no conflicts of interest
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
International Journal of Corrosion 9
ONaSO
O(3((2)10(2O
(a)
water chloride
(b)
water chloride
(c)
Figure 8 (a) Structure of sodium lauryl sulphate (b) SAMPLE 1 watermolecules and chloride ions are attached on steel surface (c) SAMPLE2 coordinated SLS prevent the migration of water molecules and chloride ions towards steel surface
References
[1] W Li C Xu S Ho B Wang and G Song ldquoMonitoringConcrete Deterioration Due to Reinforcement Corrosion byIntegrating Acoustic Emission and FBG Strain MeasurementsrdquoSensors vol 17 no 3 p 657 2017
[2] S Ahmad ldquoReinforcement corrosion in concrete structures itsmonitoring and service life predictionmdasha reviewrdquo Cement andConcrete Composites vol 25 no 4-5 pp 459ndash471 2003
[3] P C Aıtcin ldquoThe durability characteristics of high performanceconcrete a reviewrdquoCement andConcrete Composites vol 25 no4-5 pp 409ndash420 2003
[4] S Altoubat M Maalej and F U A Shaikh ldquoLaboratorySimulation of Corrosion Damage in Reinforced ConcreterdquoInternational Journal of Concrete Structures and Materials vol10 no 3 pp 383ndash391 2016
[5] M F Montemor M P Cunha M G Ferreira and A MSimoes ldquoCorrosion behaviour of rebars in fly ash mortarexposed to carbon dioxide and chloridesrdquoCement and ConcreteComposites vol 24 no 1 pp 45ndash53 2002
[6] B Reddy G K Glass P J Lim and N R Buenfeld ldquoOnthe corrosion risk presented by chloride bound in concreterdquoCement and Concrete Composites vol 24 no 1 pp 1ndash5 2002
[7] S Nesic J Postlethwaite and S Olsen ldquoAn ElectrochemicalModel for Prediction of Corrosion of Mild Steel in AqueousCarbon Dioxide Solutionsrdquo Corrosion vol 52 no 4 pp 280ndash294 1996
[8] G I Ogundele and W E White ldquoSome Observations on Cor-rosion of Carbon Steel in Aqueous Environments ContainingCarbon Dioxiderdquo Corrosion vol 42 no 2 pp 71ndash78 1986
[9] S M AbdEl Haleem S Abd ElWanees E E Abd El Aal and ADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel II Role of some anions in the initiation andinhibition of pitting corrosion of steel in Ca(OH)2 solutionsrdquoCorrosion Science vol 52 no 2 pp 292ndash302 2010
[10] SM AbdEl Haleem S AbdElWanees E E AbdEl Aal andADiab ldquoEnvironmental factors affecting the corrosion behaviorof reinforcing steel IVVariation in the pitting corrosion currentin relation to the concentration of the aggressive and theinhibitive anionsrdquo Corrosion Science vol 52 no 5 pp 1675ndash1683 2010
[11] M S Darmawan ldquoPitting corrosion model for reinforcedconcrete structures in a chloride environmentrdquo Magazine ofConcrete Research vol 62 no 2 pp 91ndash101 2010
[12] M S Anwar B Fadillah A Nikitasari S Oediyani and EMabruri ldquoStudy of Pitting Resistance of Rebar Steels in JakartaCoastal Using Simulated Concrete Pore Solutionrdquo ProcediaEngineering vol 171 pp 517ndash525 2017
[13] J G Cabrera ldquoDeterioration of concrete due to reinforcementsteel corrosionrdquo Cement and Concrete Composites vol 18 no 1pp 47ndash59 1996
[14] X G Feng G H Dong and J Y Fan ldquoEffectiveness ofan inorganic corrosion inhibitor in pore solution containingsodium chloriderdquo Applied Mechanics and Materials vol 556-562 pp 158ndash161 2014
[15] A U Malik I Andijani F Al-Moaili and G Ozair ldquoStudies onthe performance ofmigratory corrosion inhibitors in protectionof rebar concrete in Gulf seawater environmentrdquo Cement andConcrete Composites vol 26 no 3 pp 235ndash242 2004
[16] A M Vaysburd and P H Emmons ldquoCorrosion inhibitorsand other protective systems in concrete repair concepts ormisconceptsrdquo Cement and Concrete Composites vol 26 no 3pp 255ndash263 2004
[17] H Oranowska and Z Szklarska-Smialowska ldquoAn electrochem-ical and ellipsometric investigation of surface films grown oniron in saturated calcium hydroxide solutions with or withoutchloride ionsrdquoCorrosion Science vol 21 no 11 pp 735ndash747 1981
[18] C Cao ldquoOn electrochemical techniques for interface inhibitorresearchrdquoCorrosion Science vol 38 no 12 pp 2073ndash2082 1996
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
10 International Journal of Corrosion
[19] S Qian and D Cusson ldquoElectrochemical evaluation of the per-formance of corrosion-inhibiting systems in concrete bridgesrdquoCement and Concrete Composites vol 26 no 3 pp 217ndash2332004
[20] U Angst B Elsener C K Larsen and Oslash Vennesland ldquoCriticalchloride content in reinforced concretemdasha reviewrdquoCement andConcrete Research vol 39 no 12 pp 1122ndash1138 2009
[21] S A Al-Saleh ldquoAnalysis of total chloride content in concreterdquoCase Studies in Construction Materials vol 3 pp 78ndash82 2015
[22] A Welle J D Liao K Kaiser M Grunze U Mader and NBlank ldquoInteractions of NN1015840-dimethylaminoethanol with steelsurfaces in alkaline and chlorine containing solutionsrdquo AppliedSurface Science vol 119 no 3-4 pp 185ndash190 1997
[23] A Krolikowski and J Kuziak ldquoImpedance study on calciumnitrite as a penetrating corrosion inhibitor for steel in concreterdquoElectrochimica Acta vol 56 no 23 pp 7845ndash7853 2011
[24] F Wombacher U Maeder and B Marazzani ldquoAminoalcoholbased mixed corrosion inhibitorsrdquo Cement and Concrete Com-posites vol 26 no 3 pp 209ndash216 2004
[25] C K Nmai ldquoMulti-functional organic corrosion inhibitorrdquoCement and Concrete Composites vol 26 no 3 pp 199ndash2072004
[26] J M Gaidis ldquoChemistry of corrosion inhibitorsrdquo Cement andConcrete Composites vol 26 no 3 pp 181ndash189 2004
[27] P Montes T W Bremner and D H Lister ldquoInfluence ofcalcium nitrite inhibitor and crack width on corrosion of steelin high performance concrete subjected to a simulated marineenvironmentrdquo Cement and Concrete Composites vol 26 no 3pp 243ndash253 2004
[28] M A Asaad M Ismail M M Tahir G F Huseien P B Rajaand Y P Asmara ldquoEnhanced corrosion resistance of reinforcedconcrete Role of emerging eco-friendly Elaeis guineensissilvernanoparticles inhibitorrdquo Construction and Building Materialsvol 188 pp 555ndash568 2018
[29] M G L Annaamalai G Maheswaran N Ramesh C KamalG Venkatesh and P Vennila ldquoInvestigation of CorrosionInhibition of Welan Gum and Neem Gum on Reinforcing SteelEmbedded in Concreterdquo International Journal of Electrochemi-cal Science vol 13 pp 9981ndash9998 2018
[30] A Kumar ldquoCorrosion Inhibition of Mild Steel in HydrochloricAcid by Sodium Lauryl Sulfate (SLS)rdquo E-Journal of Chemistryvol 5 Article ID 574343 6 pages 2008
[31] M L Cedeno L E Vera and T Y Pineda ldquoA study ofcorrosion inhibition of steel AISI-SAE 1020 inCO2 -brine usingsurfactant Tween 80rdquo Journal of Physics Conference Series vol786 Article ID 12038 2017
[32] H J Flitt and D P Schweinsberg ldquoEvaluation of corrosionrate from polarisation curves not exhibiting a Tafel regionrdquoCorrosion Science vol 47 no 12 pp 3034ndash3052 2005
[33] J Chen and X Zhang ldquoAC impedance spectroscopy analysisof the corrosion behavior of reinforced concrete in chloridesolutionrdquo International Journal of Electrochemical Science vol12 no 6 pp 5036ndash5043 2017
[34] D V Ribeiro C A C Souza and J C C Abrantes ldquoUse ofElectrochemical Impedance Spectroscopy (EIS) to monitoringthe corrosion of reinforced concreterdquo Revista IBRACON deEstruturas e Materiais vol 8 no 4 pp 529ndash546 2015
[35] K V S Ramana S Kaliappan N Ramanathan and V KavithaldquoCharacterization of rust phases formed on low carbon steelexposed to natural marine environment of Chennai harbour -South Indiardquo Materials and Corrosion vol 58 no 11 pp 873ndash880 2007
[36] T Zhao andGMu ldquoThe adsorption and corrosion inhibition ofanion surfactants on aluminium surface in hydrochloric acidrdquoCorrosion Science vol 41 no 10 pp 1937ndash1944 1999
[37] Y Zhu M L Free R Woollam and W Durnie ldquoA review ofsurfactants as corrosion inhibitors and associated modelingrdquoProgress in Materials Science vol 90 pp 159ndash223 2017
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom
CorrosionInternational Journal of
Hindawiwwwhindawicom Volume 2018
Advances in
Materials Science and EngineeringHindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Journal of
Chemistry
Analytical ChemistryInternational Journal of
Hindawiwwwhindawicom Volume 2018
ScienticaHindawiwwwhindawicom Volume 2018
Polymer ScienceInternational Journal of
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
Advances in Condensed Matter Physics
Hindawiwwwhindawicom Volume 2018
International Journal of
BiomaterialsHindawiwwwhindawicom
Journal ofEngineeringVolume 2018
Applied ChemistryJournal of
Hindawiwwwhindawicom Volume 2018
NanotechnologyHindawiwwwhindawicom Volume 2018
Journal of
Hindawiwwwhindawicom Volume 2018
High Energy PhysicsAdvances in
Hindawi Publishing Corporation httpwwwhindawicom Volume 2013Hindawiwwwhindawicom
The Scientific World Journal
Volume 2018
TribologyAdvances in
Hindawiwwwhindawicom Volume 2018
Hindawiwwwhindawicom Volume 2018
ChemistryAdvances in
Hindawiwwwhindawicom Volume 2018
Advances inPhysical Chemistry
Hindawiwwwhindawicom Volume 2018
BioMed Research InternationalMaterials
Journal of
Hindawiwwwhindawicom Volume 2018
Na
nom
ate
ria
ls
Hindawiwwwhindawicom Volume 2018
Journal ofNanomaterials
Submit your manuscripts atwwwhindawicom