2011-10-31 214030 1070481 Summary

ODICE (acronym of COmputatonally driven Design of Innovative CEmenticious materials") is an ambitious research project that has brought

producers and suppliers of cement-based materials together with universities and research institutes for the development of new and radically improved computational toolkits that monitor the formation and properties of cementitious materiales by starting from macroscopic processing variables (size of the cement grains, water-cement ratio, temperature, cement grain composition...).

he computational toolkits that have been developed in the CODICE project will radically boost the competitiveness of the European Cement and

Construction sectors, since they will provide valuable and cheap tools to: - Optimise the processing of cement (special attention is paid to the computational design of cements which entail lower CO2 emissions and lower energy consumptions). - Decrease significantly the time and the costs of the quality control assessments. - Optimise the design of the cement-based materials (either in terms of their mechanical performance or their life-cycle analysis).

part from the knowledge of Tecnalia in the nano and sub-micro modelling of cementitious materials, the project has also incorporated the long-

standing expertise of the TU Delft in the micro-modelling of cement-based materials and the superb know-how of University of Bonn in scientific computing. Besides, the project has run in parallel an experimental research program devoted to validate the computational predictions. To this end the project also included the contribution of prestigious experimentalists from the University of the West of Scotland and the Instituto Eduardo Torroja. Finally, the partnership was completed by the solid commitment of CTG Italcementi, BASF SA and BIKAIN; three industrial companies which (all together) target the whole Construction Sector business and guarantee that their industrial feeling is properly addressed.

www.codice-project.eu re you interested in this project? Please contact the project coordinator:

Dr. Jorge S. Dolado TECNALIA

[email protected] Tel: +34 647 40 33 13

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An European project supported by the SeventhFramework Programe for Research and TechnicalDevelopment. Contract number 214030

An European project supported by the SeventhFramework Programe for Research and TechnicalDevelopment. Contract number 214030

ThisresearchwascarriedoutbytheCODICEpartnershipwiththeeconomicalsupportoftheFP7programoftheEuropeanCommission(contractNMP3SL2008214030).

or themodelling, at amultiscale,

the evolution of themechanical performance of non

degradedanddegradedcementitiousmatrices,aseriesofexperimentswereplannedwithpuresynthetic T1C3S and C2S, in order to obtaindifferent CSH gel structures during theirhydration. The characterization of the CSHgels and matrices will provide experimentalparameters for thevalidationof themodellingschemeproposed.

quantitativemethod,basedon

thermalanalyses,hasbeenused for thedeterminationofthechemicalcompositionofthecalciumsilicatehydrategel(CSH) togetherwith the degree of hydrationand quantitative evolution of all thecomponents of the pastes. Besides, themicrostructureandtypeofsilicatetetrahedronandmean chain length (MCL)were studiedbyscanning electron microscopy (SEM) and 29Simagicanglespinning(MAS)NMR,respectively.

hemain results showed that thechemical compositions for theC

SH gelshave aCaO/SiO2molar ratioof 1.7for both C3S and C2S compounds, which isindependent of the hydration time. Smalldifferences were found in the gel watercontent: The value of the H2O/ SiO2 molarratio, in the case of C3S, decreases slightlyoverhydration:2.90.2to2.60.2from1dayto28days.Nevertheless, in the caseof theC2S,thevalueoftheH2O/SiO2molarratiooftheCSHgelrangedfrom2.40.2to3.20.2from7days to90daysofhydration. In thecase of CSH gel from C3S hydration, themeanchain length(MCL)values,determinedfrom29SiMASNMR,wereoverthreesilicatetetrahedron and remained essentiallyconstant at all hydration times. This value(3.5)isconsistentwithanequalpopulationofdimericjenniteandpentamerictobermorite

likestructures,which

like structures,which isalsoconsistentwithaC/S ratio close to 1.7, as the TG results havealsoconcluded. InthecaseoftheCSHgelofthe hydrated C2S, the corresponding value ofMCLwas4,whichconsistentwithapopulationof 33% of dimeric jennite and 67% ofpentamerictobermorite(Sara Goi et al. Quantitative study ofhydration of C3S and C2S by thermal analysis.Evolution and composition of CSHgelsformedJ.Therm.Anal.Calorim.102(2010)pp.965973).

or more information, please contact Dra.Sara Goi ([email protected]) or visit ourwebpagehttp://codiceproject.eu

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52.6

25.2

10.4

71.5

38.7 31.222.8

11.8

29.9 36.142.8

17.013.8

20.6

28.5

13.815.7

17.6

0

25

50

75

100

125

0 1 3 7 28Hydration time/days

Mas

s fr

actio

n di

strib

utio

n/% C-S-H PORTLANDITE

FREE WATER unreacted C3SC3S

71.560.0

41.0 32.2

48.736.6

13.1

5.1

1.5

3.925.4

18.5

14.0

28.5

0

25

50

75

100

125

0 7 28 90Hydration time (days)

Mas

s fr

actio

n di

strib

utio

n/% C-S-H PORTLANDITE

FREE WATER unreacted C2SC2S

CODICEProject Researchhighlights May2010

QuantitativestudyofhydrationofC3SandC2Sbythermalanalysis

Mass fractiondistributionofallthecomponentsofC3SandC2Spastes,determinedfromquantitativeTGresults.


hehydrationprocessesofT1C3Sand C2S and theirmixtures 70

30and30 70 (% in weight) have beenfollowedbyconductioncalorimetricstudies.Thesynergy of the T1C3S and C2S hydrationreactions,acrosstheirmixtures inproportionsof7030 and 3070, has been studied through thequantification of the portlandite carried out bythermogravimetricanalysis.

he microstructure was studied by

scanningelectronmicroscopy,thetypeof silicate tetrahedron, and mean chainlength of the CSH gel by 29Si magic anglespinning nuclear magnetic resonance, and theporosity and poresize distribution by mercuryintrusionporosimetry.

he main results showed that the

hydraulicactivityof theC2Sstronglyincreased in the presence of T1C3S,

mainly at early stages, avoiding its inactiveinduction period. As a consequence of theincreaseofthehydraulicactivityoftheC2S,thepore microstructure is refined and the surfaceareaisdiminished.

(MS.Hernndezetal.SynergyofT1C3SandC2S Hydration Reactions J. Am. Ceram. Soc.,(2010)DOI:10.1111/j.15512916.2010.04214.x

For more information, pleasecontact Dra. Maria Soledad Hernndez([email protected]) or visit ourwebpagehttp://codiceproject.eu

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CODICEProject Researchhighlights October2010

SynergyofT1C3SandC2SHydrationReactions

6.1

2.21.05

6.2

2.971.0

8.5

5.4

1.8

12.4

6

1.1

0

5

10

15

20

25

Pore

-siz

e di

strib

utio

n (%

)

100-0 70-30 30-70 0-100

C3S-C2S

> 10um 0.05-10 um0.01-0.05 um < 0.01 um

28 days

10 m

Portlandite

70-30

C-S-H

C-S-H gel

30-70

P

P

10 m

100-0

20 m

0.0

0.2

0.4

0.6

0.8

1.0

1.2

1 10 100Hydration time (days)

hydr

atio

n de

gree

100-0 0-10070-30 30-70

predicted 30-70 line predicted

70-30 line

0 25 50 75 100 125 1500

100

200

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Time (h)

Hea

t Rel

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d (J

/g)

100-0

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30-70

0-100

CODICEProjectResearchhighlightsDecember2010

DECIPHERINGTHESMALLESTUNITSOFCSHGEL


hemost important ingredientofcementitiuousmaterialsisa

hydration product called CalciumSilicateHydrate (CSH) gel. CSH gel isextremely bewildering. While someexperimental techniques taught us thatitsshortorderingisakintothisfound inclaylike minerals as tobermorite andjennite, others have recognized theexistence of small CSH units (about 4nm sized) fromwhich thewhole CSHstructure is assembled. The how andwhy of the formation of these 4nmunitsremainedunanswered.Researchesof the CODICEs partnership haveunravelled this longstanding mysterybysophisticatedatomisticsimulations(J. S. Dolado et al. TheNanobranchedStructureofCementitiousCSHgel;Journal of Materials ChemistryDOI:10.1039/C0JM04185H).

ThenanobranchedstructureofCSHgelobtainedbyMolecularDynamicsimulations.OnlyCaandSiatomsareshowningreenforclarity.

.

In essence our Molecular Dynamicsimulationspredict theappearanceofabranched threedimensional CSHnanostructure where the segmentalbranchesare~3x3x6nmsizedpiecesofCSH gel. This finding provides for thefirsttimeasatisfactorycomparisonwiththeSANSandwatersorption/desorptionmeasurements, while concurrentlyaccounting for the microstructuralinformationgained fromNMR,XRDandINSexperiments

likethedeciphermentofDNAis enabling an extraordinary

progressingentherapy,thediscoveryofthe smallest bricks which make upmaterials can revolutionize materialsscience and engineering. In this sense,ourwork isanalogoustodecipherertheDNA of cementitious materials (i.e.thesmallestbuildingbricksofCSHgel).It is clear thatournovel results lead toanunprecedentedunderstandingof thecementitious nanostructure formationand are a strong basis to performgenuine nanoengineering with thesesmallCSHunits so as to improve themechanicalanddurabilitypropertiesofcementbasedmaterials.

ormoreinformation,pleasecontactDr.JorgeS.Dolado

([email protected])orvisitourwebpagehttp://codiceproject.eu.

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hetexturalandmechanicalcharacterizationofCSHgelsformedfromthehydrationofpureT1C3S, C2S and their blends are studied by Nitrogen sorption and nanoindentationexperiments.WhiletwodifferentiatedzonesintheporesizedistributionoftheCSHgelsat

12nmand3nmaredetected,theproportionofbothzonesdependsontheageofhydrationandtypeofcalcium silicate, increasing the fraction of pores of 3nm as that of pores of 12 nm decreasing withhydrationtime.

he surface area and nanoporosity of CSH gels formedfromthehydrationofC2Sandthe 3070 (T1C3Sand

C2Smixture) arehigher than those fromhydrationofT1C3S, and7030 (T1C3S and C2Smixture),with the difference decreasingwithhydrationage.

uchchangesin

microstructurefeatures are well supportedby findings ofnanoindentation study,which shows the greaterrelative volume of CSHphases with lower densitiesin the C2S and the 3070

pastes than in theT1C3Sand7030pastes. With the increase inhydration age, the relative volume of CSH phases with higherdensitiesincreasedattheexpensesofthosewithlowerdensity.

Important quantitative correlationswere found amongthese textural characteristics and themean chain length, determined from 29Simagicanglespinning(MAS)NMR,oftheCSHgels.(Goietal.MaterialesdeConstruccin(inpress).

Formoreinformation,pleasecontactDra.SaraGoi([email protected])orvisitourwebpagehttp://codiceproject.eu

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CODICEProject Researchhighlights June2011

TEXTURALANDMECHANICALCHARACTERIZATIONOFCSHGELSFROMHYDRATIONOFSYNTHETIC

T1C3S,C2SANDTHEIRBLENDS

0.0

0.2

0.4

0.6

0.8

1.0

1 2 3 4 5 6

Mean chain length

Frac

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of p

ore

volu

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(cm

3 /g) 100-0

0-10070-3030-70 3 nm

12 nm

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0 20 40 60 80 100

C-S

-H (%

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100-0 0-10070-30 30-70

0

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10

15

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0 20 40 60 80 100

Hydration time (days)

surf

ace

area

(m2 /g

) 100-0 0-10070-30 30-70

100-0y = 6.4x - 1.5R2 = 0.9664

0

20

40

60

80

100

0 5 10 15 20Surface area (m2/g)

C-S

-H g

el (%

)

100-070-3030-700-100


-65 -70 -75 -80 -85 -9 0 -95p pm

-65 -7 0 -75 -80 -85 -90 -95p pm

-65 -70 -75 -80 -85 -9 0 -95p pm

-65 -7 0 -75 -80 -85 -90 -95p pm

C3S

C3S

-65 -70 -75 -80 -85 -90 -95pp m

-65 -70 -75 -80 -85 -90 -95pp m

-65 -70 -75 -80 -85 -90 -95pp m

-65 -70 -75 -80 -85 -90 -95pp m

C2S anh

C2S 28 d

-65 -70 -75 -8 0 -85 -90 -9 5p p m

-65 -70 -75 -8 0 -85 -90 -9 5p p m

-65 -70 -75 -8 0 -85 -90 -9 5p p m

-65 -70 -75 -8 0 -85 -90 -9 5p p m

A anh

A 28 d

-65 -70 -7 5 -8 0 -85 -90 -95pp m

-65 -70 -7 5 -8 0 -85 -90 -95ppm

-65 -70 -7 5 -8 0 -85 -90 -95pp m

-65 -70 -7 5 -8 0 -85 -90 -95ppm

B anh

B 28d

0.0000

0.0005

0.0010

0.0015

1 10 100 1000Average pore diameter (nm)

dV/d

(D) P

ore

volu

me

(cm

3 /g-n

m)

C3SC2SAB

28 days

hepresentpaperdiscussesmicroandnanoscalestudiesofthecementitiousskeletons

formingduringthehydrationofC3S,C2Sand70%/30%blendsofbothC3S/C2SandC2S/C3Switha water/cementratioof0.4.Thehydratedpasteswerecharacterizedatdifferentcuringageswith29SiNMR,SEM/TEM/EDS,BET,andnanoindentation.

he findings served as a basis for the micro and

nanoscale characterization of the hydration productsformed,especiallyCSHgels.Differenceswere identified in

composition, structure andmechanical behaviour (nanoindentation),dependingonwhether thegels formed inC3SorC2Spastes.TheC3Sgelshadmorecompactmorphologies,smallerBETN2specificsurfaceareaand lesserporosity thanthegelsfromC2Srichpastes.

he resultsofnanoindentation testsappear toindicate that the various CSH phases formed inhydrated C3S and C2S have the same mechanical

properties as those formed in Portland cement paste.ComparedtotheC3Ssample,thehydratedC2Sspecimenwasdominatedbythe loosepacked(LP)andthelowdensity(LD)CSHphases,andhadamuchlowercontentofthehighdensity(HD)CSHphase.

(Puertas et al. 13th

INTERNATIONAL CONGRESS ON THECHEMISTRYOFCEMENTMadrid,3 8July2011).

For more information, please

contact Dra. Francisca Puertas([email protected]) or visit ourwebpagehttp://codiceproject.eu

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Ca/Si atomic ratio

C3S C2S A B

Inner C-S-H 1.8 0.3 1.6 0.2 1.80.1 2.00.2 Outer C-S-H 1.7 0.2 1.5 0.1 1.70.1 1.7 0.1

T MCL Q2/QTOTAL Q2/Q1

C3S 3.80 0.47 0.90 A 3.65 0.45 0.83 B 3.53 0.43 0.76

C2S 3.90 0.49 0.96

CODICEProject Researchhighlights July2011

HydrationofC3S,C2SandtheirBlends.MicroandNanoscaleCharacterization

A C2S


his paper reports results of micro/nano scale characterisation and mechanical property

mappingofWhiteOrdinaryPortlandCement(WOPC)andpuresyntheticC2Scementitiousskeletonsformedbythehydrationatdifferentages.Resultsofthemappingandstatistical

indentationtestingappeartosuggestthepossibleexistenceofmorehydratephasesthanthecommonlyreportedLDandHDCSHandCHphases.ThecomparativemicrostructuralstudyofWOPCandC2Spastesrevealedveryclosemicrostructures.

(Howind et al. 13thINTERNATIONAL CONGRESSON THE CHEMISTRY OFCEMENT Madrid, 3 8 July2011).Formore information,please

contactTorstenHowind([email protected])orvisitourwebpagehttp://codiceproject.eu

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a) BSEM image b) Youngs modulus map c) Hardness map

Nanoindentationtestgrid(87x87m)

EDSanalysis50x50m

Nanoindentationtestgrid100x80m

50m

a) BSEM image b) Youngs modulus map c) Hardness map

CODICEProject Researchhighlights July2011

Mappingofmechanicalpropertiesofcementpastemicrostructures

BSEMimageandmechanicalpropertiesmapsofthetestedarea(90daysC2Spaste)

BSEMimageofthetestedarea(900indents)inWOPCpasteandcorrespondingmechanicalpropertiesmapsforE andH

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0.01

0.02

0.03

0.04

0.05

0.06

0 10 20 30 40 50

Young's modulus, GPa

Prob

abili

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ensi

ty

Exp.

Fit

Model 1

Model 2

Model 3

Model 4

Model 5

Model 6

0.00

0.01

0.02

0.03

0.04

0.05

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Young's modulus, GPa

Prob

abili

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ensi

ty

a) 4-modal Gaussian distribution curves b) 6-modal Gaussian distribution curves

CODICEProjectResearchhighlightsAugust2011

3DSIMULATIONOFCALCIUMLEACHINGINCEMENTMATRICES


alcium leaching is adegradation process

consisting in theprogressivedissolutionofthecementpastebythemigrationofthe calcium ions to the aggressivesolution.Itisthereforeatypicalexampleof a dissolution process in a porousmatrix where some of the mineralphases of the paste dissolve in theinterstitial pore solution. Furthermore,thefactthatthecementpasteisamultiphase and multiscale material addsevenmorecomplexitytotheproblem.Within the framework of the CODICEproject, researchers of Tecnalia, Bonn

UniversityandT.U.Delfhavedevelopedthe necessary tools to simulate in 3Dcalciumleachingincementcomposites.

First,anupdatedversionofHymostrucisused to create the cement compositeattending to different physicochemicalparameters. Then the degradationprogram simulates the calcium leachingof the cement paste. And finally, theanalysis software transforms theobtained output into data of time orspatial evolution of parameters such ascalcium to silicon ratio, porosity orelasticpropertiesofindividualphases.

Thisnewtoolswillcontributenotonlytoa better understanding of thephenomenon of calcium leaching butthey will also help engineers to thedesign of safer structures with smalleramountofmaterial.In order to contribute to the diffusionof the obtained results between theindustrial and scientific communitiesthe obtained resultswill be presentedintheconferencesMicrodurability2012andNICOM4.

ormoreinformation,pleasecontactDr.JuanJ.Gaitero

([email protected])orvisitourwebpagehttp://codiceproject.eu.

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a) b)

c) d)

a) b)

c) d)

Evolution of the degradation front along time.Micrographsa)0,b)5,c)10andd)15timesteps.Thesideofthecubeis10m.InnerProductCSHappearsinred, Outer Product CSH appears yellow, OverlappingCSH isdisplayed ingreenandPorosity ispaintedblue.Foreachparticularphasedarker tonesarecorrespondtogreatercalciumcontent.

2011-10-31 214030 1070481 Summary

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