Seminar: Fibre reinforced concrete and durability ... · Bouteiller et al, Corrosion Reviews 2012...

Corrosion of reinforced concrete structures

from the diagnosis to the electrochemical repair

[email protected]

http://www.ifsttar.fr/accueil/

Chalmers University of Technology

Seminar: Fibre reinforced concrete and durability

September 13, 2017

French institute of science and

technology for transport,

development and networks

Introduction

Initiation

Propagation, Cracks

Electrochemicalrepair treatments

Chalmers seminar - 13 September 2017 - V. Bouteiller 2

-3.00E-06

-2.00E-06

-1.00E-06

0.00E+00

1.00E-06

2.00E-06

3.00E-06

-0.4 -0.35 -0.3 -0.25 -0.2 -0.15 -0.1 -0.05 0

Potentiel(V)

Cou

rant

(A)

05-T

19-C

10-G

13-I

1

2

3

4

Introduction Initiation Propagation, Cracks Electrochemical repair


Building - G.Taché - CEBTP Historical monuments –E. Marie-Victoire- LRMH

Bridge – V. Bouteiller - Ifsttar

Dam- J-F. Seignol - Ifsttar

Nuclear plant - EDFTunnel - C. Larive- CETU


Two main causes of the corrosion of reinforcement– Complete carbonation of the concrete cover � pH decreases from 13 to 9– Chloride contamination � breakdown of the passive film

Damages– Steel section loss– Cracks...delaminations– Loss of steel/concrete adhesion

4Chalmers seminar - 13 September 2017 - V. Bouteiller

Fe → Fe2+ + 2e- O2 + 2H2O + 4e- → 4OH-2H+ + 2e- → H2

AnodeCathode Cathode

emetal

concrete

e- e-

Volume of corrosion products > Volume iron metal

FeO

Fe3O4 Fe2O3

Fe(OH)2

Fe(OH)3

Fe(OH)3, 3H2O

Fe

0

1

2

3

4

5

6

7


Road bridges– 6 000 national roads (/ 16 000)– 75% surface reinforced or pre-stressed concrete – 35 years old– 10% structurally deficient

Infrastructure plan- Reliable tools for corrosion diagnosis- Simulations to predict the bridge life- New repair solutions based on electrochemical treat ments


+ Marine environment bridges


Research on service life is mainly based on durabil ity issues but corrosion by itself should also be studied

– Concrete cover deals with transport mechanisms – Steel/concrete composite deals with electrochemical processes

Actors– Universities, institutes, laboratories, industries, companies, – Researchers, engineers, owners, architects, users, …


Corrosion

DurabilityPhysics and Chemistry Electrochemistry

Mechanics Models

CorrosionCorrosion

e

concrete

steelconcrete cover



7 / 38Chalmers seminar - 13 September 2017 - V. Bouteiller

Time

Cor

rosi

on c

urre

nt

SoundCarbonated Chloride contaminated (W/D cycles)Chloride contaminated (mix)

TemperatureHumidityOxygenRain

Measurements frequencyRepair durability

CONTAMINATION

TIMETOOLSLaboratory potentiostatsOn-site apparatus

t1 ? t2 ? t3 ?

Carbon steelStainless steel

METAL

CORROSION MODES

(1)Ingress of

active species

(2)Corrosion initiation

(3)Corrosion

propagation

(4)Cracks

Ruin

i1 ?

i2 ?

i3 ?

Impressed currentGalvanic current

PROCESS

ENVIRONMENT

AcceleratedNatural aging

PortlandGGBS

CEMENT TYPE


Introduction

Initiation

Detection of the initiation of corrosion / cement a bility to delay the ingress of chloride ionsReinforced micro-concretePortland vs Ground Granulated Blast furnace Slag cem ents NDT electrochemistry and DA chloride profilesCorrelation chloride threshold and performed testsBouteiller et al, Cement and Concrete Research, 2012

Propagation, Cracks

Electrochemical repair treatments

Chalmers seminar - 13 September 2017 - V. Bouteiller 8 / 38

1

2

3

4


Objectives– Evaluate the cement ability to delay the chloride i ngress and therefore the corrosion – NDT electrochemical measurements (HCP, LPR) and Ico rr

Specimen designParameters

– Cement type Portland or Ground Granulated Blast furnace Slag– Water/cement ratio

Tests– NDT: 10 samples (average) and ↓ number– DA: chloride profiles 1 sample– Autopsies



P 0.45 P 0.65 L 0.45 L 0.65

cement P P GGBS GGBS

w/c ratio 0.45 0.65 0.45 0.65

cement (kg/m3) 573 396 573 396

porosity* (%) 18.5 20.96 20.56 23.51

resistance (MPa) 54.7 33.5 55.7 25.4

W/D cycles (NaCl 35g/l)

Steel Fe24

Surface 10 cm²

MicroConcrete

10 mm

70 mm

30 mm30 mm

32 mm

95 mm

2-31-2 0-1

2-30-1

1-2

Portland cement (P; w/c= 0.65 or 0.45) GGBS 70% (L; w/c= 0.65 or 0.45)


� Cl- penetration = 3 cm (=steel)• P-0.65 : 7-14 weeks; P-0.45 : 28-42 weeks• L : none after 70 or 105 weeks

Modéré

Faible

Négligeable

(56 weeks)P-0,65 P-0,45 L-0,65 L-0,45

� NDT sulfurs in GGBS ≠ corrosion of reinforcement� Good agreement of results from NDT, Cl - analysis and autopsies

Cl- NDT

Autopsies


Portland cement (P 0.65)

Chloride threshold 0.04% < [Cl -tot ] < 8.34% Angst 2009 CCR


� Ecorr (-276mV) : [Cl -tot ] > 1% and icorr < 0.01 µA/cm² : no agreement with initiation

� icorr (>0.1 µA/cm²) : [Cl -tot ] > 2.2% and Ecorr ≈-550mV : agreement with initiation

> 0.3% > 1,4%

1<High

0,1<Moderate<0,5

Negligible <0,1

> 2,2%> 1%

� Different conclusions based on total or free chlori de contents


Total chlorides (% weight cement) Free chlorides (% weight cement)

Introduction

Initiation

Propagation, Cracks

Corrosion versus time for predictionReinforced concrete prismsDifferent contaminationsDifferent environmental conditionsNDT electrochemical measurements Mathematical relation of corrosion CracksBouteiller et al, European Journal of Environmental and Civil Engineering 2012Bouteiller et al, Corrosion Reviews 2012Bouteiller et al, Construction and Building Materials 2016



1

2

3

4


Objective: Find a mathematical law of corrosion in the propagation phase depending on concrete state and climate conditions � prediction

Specimen: Reinforced concrete prisms(15x5x5cm, rebar diameter 6mm, length 10cm)

Parameters: – Concrete states (4)

• Reference � T• Chloride in the mix � G• Chloride by wetting/drying cycles � I• Carbonated � C

– Environmental conditions (7)• Controlled T1=20 , T2=45 (°C) and H1=60, H2=80, H 3=92 (%RH)• Outdoor

– Measurements frequency (from Sept 2008 until March 2014): 4 times / year • Visual inspections• Electrochemical measurements• (Autopsies)




E07 (21 m) E08 (24 m) E09 (27 m)

E10 (30 m) E12 (36 m) E13 (39 m)

� Database



Icorr (µA/cm²) Corrosion levels

> 1 High

0.5 – 1 Moderate

0.1 – 0.5 Low

≤ 0.1 Negligible

Half cell potential

Linear polarisation resistance

Impedance (Nyquist)


5 channels



Steel thickness loss

Faraday's law:


� power relation seems better than linear� α > 1 (catalytic reaction Cl)

Linear: stl=at Power: stl=atα


� α increases with temperature


Cumulative steel thicknessloss (µm)

Simulation5 years

Prediction10 years

icorr max linear relation 152 304whole icorr power relation 97 253whole icorr linear relation 84 168icorr min linear relation 31 62

Cumulative steelthickness loss (µm)

Simulation5 years

icorr max linear relation 152whole icorr power relation 97whole icorr linear relation 84icorr min linear relation 31


Introduction

Initiation

Propagation, Cracks


Efficiency / Side effets / DurabilityReinforced concreteBridgesImpressed or galvanic currentsTong, Thesis, 2009

Tong et al, Cement and Concrete Research 2012

19

1

2

3

4


Chalmers seminar - 13 September 2017 - V. Bouteiller

Electrochemical treatments– Chloride extraction (14038-2)– Realcalisation (NF EN 14038-1) – Cathodic protection (ISO 12696)

Objectives– Efficiency and potential side effects – Durability


Armature - cathode

Anode

Cl- H2O

O2 OH-

Réaction cathodique normale: O2 +2H2O + 4e- -----> 4OH-

Surprotection: 2e- + 2H2O -----> H2 + 2OH-

2H2O -----> O2 + 4H+ +4e-

V+

-

Na+

ElectrolyteAnode = mats, ribbons

Cathode = reinforcement

(protection)

Patch repair technique– European CONREPNET Project (Tilly, 2007) 50% unsuc cessful

• Old and new concrete incompatibility (2 years)• Incipient anodes (10 years)

Two different processes

- Impressed current (generator)

- Galvanic current (sacrificial)


� Is the increase of pH sufficient to halt the corros ion process?


colourless pink9 10colourless pink9 10 15J 6M 12M 30M 60M Temps

1-S

3-C

Laboratoire Extérieur

7-CI 4-CI 6-CIRealcalisation par courant imposé (CI)

11-CG 8-CG 10-CGRéalcalinisation par anode sacrificielle ( (CG)

� Phenolphtalein indicator : pink ring around the reba r (1,5 cm) but colour fade with time

� Concrete suspension: pH increases from 9 to 10-11 (CI) and from 9 à 11 (CG)


� Efficient until 12 months

� For longer term, corrosion starts again

� Development of a specific cell for « in-situ » observa tions� Realcalisation is efficient but not durable

– Carbonated concrete• Green rust then lepidocrocite ( γ-FeOOH )

– During realcalisation• After 2h : (a) magnetite (Fe 3O4) and (b) brucite (Fe(OH) 2) and RV � reduction !• After 24h, (c) pure magnetite (d) pure brucite � Corrosion is halted as confirmed by the

intensities that remained stable

•

– 6 months after treatment• Oxydations magnetite in maghémite ( γ-Fe2O3) and brucite in ferroxyhite ( δ-FeOOH) �

corrosion starts again

� Confirmation of the corrosion with SEM observations

0 200 400 600 800 1000 1200

434

Ra

man

Inte

nsity

/a,u

,

Wavenumber/ cm -1

505

(a)

670

0 200 400 600 800 1000 1200

3600

422

Ram

an I

nten

sity

/a,u

,

Wavenumber/ cm -1

500

(b)

3580

200 400 600 800 1000 1200

Ra

man

Inte

nsity

/a,u

,

Wavenumber/ cm -1

(c)670

200 400 600 800 1000 1200

3400 3600

410

Ram

an I

nten

sity

/a,u

,

Wavenumber/ cm -1

498

(d)

3580


Current projects


Laboratory– Corrosion of reinforced concrete contaminated by ca rbonation and chloride

ions – Repair by ECE treatment

– Experimental and numerical studies of reinforced co ncrete structural elements damaged by corrosion

Field DeCoF-Ré Project– Reliability of a corrosion diagnosis of a bridge in a marine environment

(Pont de l'île de Ré) – Decisions

– Durability study on the piers of the ile de Ré Bridge


� PhD defense Yolaine TISSIER, October 3, 2017

� PhD defense Olfa LOUKIL, October 17, 2017

� PhD defense Lucas BOURREAU, December 19, 2017

Objective: provide an indicator of survey instead o f alarm– Corrosion of reinforcement micro and macro scales + kinetic + models

– Embedded sensors

– Natural corrosion • Guerville (R-P. Martin, IFSTTAR) • La Rochelle (LaSie)

26Chalmers seminar - 13 September 2017 - V. Bouteiller

� Project ANR MODEVIE

� APOS and CANOPEE Projects


Concrete international / November 2010

The Cattenom nuclear power plant in eastern France was built during the 1980s.

Investigations of girders after 10 years exposure in 2008. In all cases, the quantity of chloride ions was found to be less than 0.1 g Cl– per 100 g of cement.

Seminar: Fibre reinforced concrete and durability ... · Bouteiller et al, Corrosion Reviews 2012...

Documents

Transcript of Seminar: Fibre reinforced concrete and durability ... · Bouteiller et al, Corrosion Reviews 2012...