ALWC Japan

Corrosion and Protectionfor Steel pile

Yoshikazu Akira, Dr. Eng.Researcher Port and Airport Research InstituteEmail: [email protected]

Independent Administrative Institution

Port and Airport Research Institute

Aiming for technologies that can contribute to the world

Its primary goal is facilitating the smooth and efficient construction of port and airports. Another major goal is researching, developing, and improving technologies for constructing ports and airports.improving technologies for constructing ports and airports.

Research fields (2006-2011)

n Research on infrastructure for homeland securityn Research for the creation of a comfortable and beautiful homelandn Research on infrastructures for a vigorous society and economy

Independent Administrative Institution

Port and Airport Research InstituteMaterials group

Long-term exposure test pier in Hasaki(1984~) Exposure test site in PARI

(1964~)

n Corrosion and corrosion protection of steel structuresn Durability of materialsn Maintenance of port and airport facilities n Others

Contents

n Corrosion of steel

Ø Corrosion Mechanism of SteelØ Corrosion of steel in under ground Environment

Corrosion of steel in marine environmentØ Corrosion of steel in marine environment

n Corrosion Protection of steel Structures

Ø Corrosion control using thickness allowance for corrosionØ protection methods

Port facilities - Landing pier

Airport facilities - D runway in HANEDA airport

2020m1100m

http://www.pa.ktr.mlit.go.jp/haneda.html

reclamationPier (Jacket)

Design service life: 100 yearsCathodic protectionCathodic protection

(Galvanic anode method, Al Alloy)(Galvanic anode method, Al Alloy)Cathodic protectionCathodic protection

(Galvanic anode method, Al Alloy)(Galvanic anode method, Al Alloy)

Stainless steel coatingStainless steel coating(PRE:44~, Thickness:0.4mm) (PRE:44~, Thickness:0.4mm) Stainless steel coatingStainless steel coating(PRE:44~, Thickness:0.4mm) (PRE:44~, Thickness:0.4mm)

Titanium CoverTitanium CoverTitanium CoverTitanium Cover

Corrosion Protection of Steel Structures

2020m1100m

Corrosion Mechanism of Steel (1)

H O+1/2O 2OH- 2OH- H O+1/2OFe2+ Fe2+

Fe(OH)2 Fe(OH)2

Neutrality environment

Steel2e-

H2O+1/2O2 2OH-

2e-

2OH- H2O+1/2O2Fe2+ Fe2+

anodecathode cathode


H O+1/2O 2OH- 2OH- H O+1/2OFe2+ Fe2+

Fe(OH)2 Fe(OH)2

Neutrality environment

Steel2e-

H2O+1/2O2 2OH-

2e-

2OH- H2O+1/2O2Fe2+ Fe2+

anodecathode cathode

Influence of environment

Dissolved OxygenTemperature Fluid velocity

etc


Dissolved OxygenTemperature Fluid velocity

etc

Deterioration case of steel pipe pile

Corrosion environments and corrosion tendencies in marine environment

Mean Sea Level(MSL)

Mean High Water Level (MHWL)

Corrosion rate

2. Splash zone

1. Marine atmosphere(Without corrosion protection)

< 0.1 mm/year

0.3 mm/year

Concentrated Corrosion

Occurrence at just below MLWL

Mean Sea Level(MSL)

Mean Low Water Level (MLWL)

Dep

th

3. Tidal zone

4. Submerged zone

5. Below the Sea bottomSea bottom

0.1-0.3 mm/year

0.1-0.2 mm/year

0.03 mm/year

Mechanism of concentrated corrosion under marine environment

Macro cell corrosion is caused by the difference of the Dissolved Oxygen (DO) concentration.

Anode : Fe Fe2+ + 2e-

Cathode : O + 2H O +4e- 4OH-

(Corrosion)

Cathode : O2 + 2H2O +4e- 4OH-

Tidal zone

Submerged zone

DO : high

DO : low

Cathode

Anode

Splash zone

Applicable protection methods for port steel structures

Marine atmosphere

Splash zone

Protective coating

Protective coating

Protective coating

Tidal zone

Submerged zone

Below the sea bottom

Protective coating

Cathodic protection

M.L.W.L. -1mM.L.W.L.

Protective coating

Cathodic protection

Protective coatingnon


Fe2+

SRB

SO42-

S2-

Non DO environmentMicrobiologically Influenced Corrosion

Steel2e-

2H+ Fe2+H2

FeS

SRB: Sulfate- Reducing Bacteria


Fe2+

SRB

SO42-

S2-

Non DO environmentMicrobiologically Influenced Corrosion

Steel2e-

2H+ Fe2+H2

FeSInfluence of environment

SRBSulfate, SO42-

etc


SRBSulfate, SO42-

etc

SRB: Sulfate- Reducing Bacteria

Kind of bacteria related corrosion in soil

BacteriaSRBSulfate-reducing bacteria

MPBMethane-Producing Bacteria

IOBIron- Oxidation Bacteria

SOBSulfur- OxidationBacteria

IBIron Bacteria

Classification Anaerobic bacteria Aerobic bacteria

Inhabiting Clay, Sludge, Acid environment

Soil, Oil field, Sulfur Groundwater

that contains Inhabiting environment

Clay, Sludge, Reclaimed ground, rust etc

environmentof sulfuric acid

Sulfur deposit, Sewage

that contains Fe and Mn

pH 5.0 ~ 9.5 Neutrality 2.0 ~ 2.5 2.0 ~ 3.5 6 ~ 8

Nourishment SO42-

Lactic acid Acetic acid Fe2+ S, FeS Fe2+, Mn2+

HCO3-, CO32-

Reaction Reducing SO42- to S2-

Reactingmethane

Oxidizing Fe2+ to Fe3+

Oxidizing S or FeS to sulfuric acid

Oxidizing Fe(OH)2 to FeOOH orFe3O4

Microbiologically Influenced Corrosion

Exposure environment:Artificial sewage

(mg/L)Glucose 250(NH4)SO4 142KH2PO4 15.0KH2PO4 15.0MgSO4-7H2O 11.3CaCl2-2H2O 1.4FeCl3 0.1

Corrosion of Steel in under ground Environment

p Uneven environment due to stir soil

p Existing groundwaterp Connected to RC structures

Variation of kinds of soilp Variation of kinds of soilex. Moisture, Humidity and Soil quality

Aver

age

of c

orro

sion

rat

e (m

m/y

r)Corrosion rate of Steel in under ground Environment

Fig. 6.3.2

Refer: S. Moriya, S. Murase, K. Nakano, The statistical investigation into corrosion loss of the steel pope pile and sheet pipe pile under ground environment, Search for Civil Engineering Journal, 47-3, 2005 (Japanese)

Aver

age

of c

orro

sion

rat

e (m

m/y

r)

Exposure time (years)

Protection of rust layerProtection of rust layer

For rust covers penetration of O2

and H2O, corrosion rate has decreased with a lapse of time

Aver

age

of c

orro

sion

loss

(m

m/y

r)

(68.3%)(95.5%)(99.7%)

Poor condition of O2Poor condition of O2

O2 Supplied- from penetration from

Corrosion loss of Steel in under ground Environment

Ref. S. Moriya, S. Murase, K. Nakano, The statistical investigation into corrosion loss of the steel pope pile and sheet pipe pile under ground environment, Search for Civil Engineering Journal, 47-3, 2005 (Japanese)

Aver

age

of c

orro

sion

loss

(m

m/y

r)

Ave.

Service time (years)

(68.3%) - from penetration fromground due to air

- from rain or groundwater

Amount of dissolved oxygen decrease, as depth from ground deep

Aver

age

of c

orro

sion

loss

(m

m/y

r)

(68.3%)(95.5%)(99.7%)

Poor condition of O2Poor condition of O2

O2 Supplied- from penetration from

Corrosion loss of Steel in under ground Environment

Ref. S. Moriya, S. Murase, K. Nakano, The statistical investigation into corrosion loss of the steel pope pile and sheet pipe pile under ground environment, Search for Civil Engineering Journal, 47-3, 2005 (Japanese)

Aver

age

of c

orro

sion

loss

(m

m/y

r)

Ave.

Service time (years)

(68.3%) - from penetration fromground due to air

- from rain or groundwater

Amount of dissolved oxygen decrease, as depth from ground deep

Weight loss of steel due to corrosion after 100 years in common condition in soil environment was predicted about 1mmWeight loss of steel due to corrosion after 100 years in common condition in soil environment was predicted about 1mm

Other Factor of Corrosion in Soil Environment

Potential of Hydrogen (pH) in soilPotential of Hydrogen (pH) in soil

pH less than 4 : Heavy corrosion

Organic acid (ex. Humic acid) : Heavy corrosion ??

Alkalinity environment : no influence

PO43-, SiO32-, CO32-: reducing corrosion

Alkalinity environment : no influence

Microbiologically Influenced CorrosionMicrobiologically Influenced Corrosion

Constituents of soilConstituents of soil

CO2, SO2, HS : accelerating corrosion

Chloride ion, Sulfate : accelerating corrosion

Example of result of investigation (1)

Investigation of corrosion in PWRIInvestigation of corrosion in PWRI

Exposure time: 17 years

0.0240.0030.009

0.024

0.01 0.02 0.030

0

Corrosion rate (mm/yr)

-5Protection method0.2m~ : painting

0.002

0.024

0.004

0.001

0.002

0.003

5

10

15

20

25

30

35

40

0.2m~ : painting~0.2m : no protection

hardly corrodes


Corrosion rate (mm/yr)Both sides

One side : 0.0053 mm/yr


Corrosion rate (mm/yr)Both sides

Dep

th o

f gr

ound

sur

face

(m

)D

epth

of

grou

nd s

urfa

ce (

m)

2years5years

10years

Standard of corrosion control

n Civil(Brige)


n architecture(Building)


n Civil(Port)


n Civil(River)

Other index

n Relationship between resistivity of soil and corrosion rate

Corrosion rate Resistivity of soil (ohm cm)

Very high 0 ~ 500

High 500 ~ 1000

Medium 1000 ~ 2000

small 2000 ~ 10000

Very small 10000 <

Countermeasure of corrosion(corrosion protection method)

CountermeasureCountermeasure

Protection methodProtection method

Coating protectionCoating protection

Organic coatingOrganic coating

Inorganic coatingInorganic coating

PaintingPainting

Organic coatingOrganic coating

Metallic coatingMetallic coating

Corrosion control using thickness allowance for corrosionCorrosion control using thickness allowance for corrosion

Cathodic protectionCathodic protection

Using anti-corrosion materialUsing anti-corrosion material

Environment controlEnvironment control

Combined coatingCombined coatingMortar coatingMortar coating

Painting

・The ease of application ・Possible to apply to new and established structures・Structural service life : several ～more than 10 yearsseveral ～more than 10 years

Need of repair for long-term use

Primer Zinc rich paint

Middle coat Epoxy, Polyurethane, Polyester, (tar-epoxy) etc.

Top coat Polyurethane, Silicon, Fluoride paint

Heavy protective painting system

20 years exposure

Organic coating

Polyethylene lining

Underwater organic coatingConstruction by underwater paint

Only applicable to newly-constructed structures

Polyethylene liningsteel

polyethylene

adhesive

special surface treatment

Inorganic coating – mortar coating

Str

uct

ure

An example of Mortar / FRP cover method

FRP cover

Mortar

Str

uct

ure

FRP cover

Inorganic coating – electro-deposition

ElectrocoatingCaCO3

Local energyLocal energy・・wind forcewind force・・wave forcewave force・・solar powersolar powerPower supplyPower supply CaCO3

Mg(OH)2

Power supplyPower supply

DC power

Stru

ctur

e

anode

Seawater Ca2+

Mg2+

Inorganic coating – metallic coating

Covering steel with high corrosion resistance material

ex. Titanium, Stainless steel…

Classifications for this methodTitanium coating HANEDA airport

Thermal spraying(Al, Zn, Al-Zn alloy …)

Titanium coating

Stainless steel coating

Titanium clad

Stainless steel clad

Plating (Al, Zn)

Tokyo-bay Aqua Line (Route 409)

FUKUYAMA port12yearsAl Zn

Cathodic protection

Galvanic anode methodGalvanic anode method Impressed current methodImpressed current method

MLWL

-

MLWL –1m

DC Power Source+

HWL

Anode (Al, Zn, Mg )

Protective Current

HWL

MLWL –1m

Insoluble anode

Protective Current

Finally

Detailed specification design

Performance based design

n Structural performancen Durability

Corrosion of steel

Maintenance based design of steel structures

Life Cycle Management System

Maintenance planning

Regular inspection

Database

Input & reference

History of utilization

Designing and environmental condition

Proposal on countermeasures

Optimization of management and reduction of LCC

Performance evaluation

timeperf

orm

ance

Database • Inspection • Prediction• Countermeasure

Input & reference

Input & reference

Designing and environmental condition

Remaining service life and future utilizing plan

LCM System

Book on corrosion protection of steel pipe pileTitle: UndecidedAuthors: Joint research group

Dr. HamadaDr. AbeMr. ShimizuDr. Akira et al

Publication is scheduled in March, 2010.

Thank you very much for your kind attentionThank you very much for your kind attention

Technical Standard and Commentaries for Port and Harbour Facilities in Japan

It was revised in 2007.Shifted from specification design

to performance based designThe demanded performance should keep The demanded performance should keep being satisfied for the design service life.

ØAppropriate designØAppropriate constructionØAppropriate maintenance

MaterialsIt is necessary to select the using material in consideration of the quality, durability and economy.

Corrosion protection and repair of port steel structures

It will be revised in 2009.Shifted from specification design

to performance based design

Contents Contents n Corrosion of steel under marine environmentn Note on selection of corrosion protection methodsn Design of protection methodsn Construction of protection methodsn Maintenance and repair of protection methodsn Repair and reinforcement of steel structures

Maintenance and repair of port facilities

It was issued in 2007.

Contents n Maintenance planningn Maintenance and repair based on n

Life cycle managementn Inspectionn Performance evaluation n Prediction of deteriorationn Countermeasure

ALWC Japan

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