Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete...
Transcript of Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete...
![Page 1: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/1.jpg)
Radhakrishna G. PillaiConcrete Materials Research Group
(Building Technology & Construction Management Division)Department of Civil Engineering
Indian Institute of Technology Madras (IITM)
Chennai, India
http://picasaweb.google.com/sudipmoitra67/NEWS_PIX#5354282213058954946
Corrosion Mechanisms, Monitoring, and Service Life Enhancement of
Reinforced Concrete Structures
![Page 2: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/2.jpg)
Outline
• Significance of corrosion
• Corrosion mechanisms in concrete structures
• Corrosion monitoring in the field
• Ways to enhance and estimate service life
![Page 3: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/3.jpg)
The Golden Gate Bridge, San Francisco, USA is facing a lot of corrosion issues
![Page 4: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/4.jpg)
After just 13 years of service, tendons in the Sunshine Skyway bridge, Florida failed
![Page 5: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/5.jpg)
Wire mesh to protect the spalled concrete from falling onto the vehicles underneath the Mercier Bridge, Montreal, Canada
![Page 6: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/6.jpg)
The cost of corrosion is significant
• In 2012, the direct cost of corrosion in India was Rs. 2 lakhs crores/year!
FHWA 1998, George Hays 2004
A corrosion protection strategy to minimise the
repair and maintenance costs is a MUST
Corrosion cost split-up in the USA (FHWA 1998)
![Page 7: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/7.jpg)
Outline
• Significance of corrosion
• Corrosion mechanisms in concrete structures
• Corrosion monitoring in the field
• Ways to enhance and estimate service life
![Page 8: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/8.jpg)
Why does iron corrode?
( )222 4442 OHFeFeOHO →++
( ) ( )3222 424 OHFeOHOOHFe →++
( ) OHOFeOHFe 2323 624 +→3.
2.
1.
Blast FurnaceIron Ore(Fe2O3)
( )222 4442 OHFeFeOHO →++
( ) ( )3222 424 OHFeOHOOHFe →++
Molten materialRolling/ other manufacturing
processes
Exposure conditions
“Dust to dust . . . back to its lowest energy state”Corrosion = Extractive metallurgy in reverse
![Page 9: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/9.jpg)
Concrete – An Introduction
• Concrete microstructure and pore solution – C-S-H– Ca(OH)2; NaOH; KOH– Many other complex
chemical compounds
http://www.scielo.br/scielo.php?pid=S1516-14392002000300012&script=sci_arttext
Neutral
0 1 32 54 6 7 98 1210 11 1413
Acidic Alkaline
pH scale
pH = -log10[H+]
pH of concrete pore solution
![Page 10: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/10.jpg)
Steel – An Introduction
• Ferrous alloys with various elements such as C, Mn, P, S, Si, Ni, Mo, Cr, V etc.
www.trincoll.edu/~alehman/PhotoENGR232_03SEM.htm
![Page 11: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/11.jpg)
Why steel embedded in uncontaminated concrete does not corrode?
• Steel does not corrode due to high pH of concrete pore solution
• A protective layer (“Passive film”) is formed– A thin, invisible, and stable
layer of initial corrosion products (i.e., iron oxides and hydroxides).
Hoar (1967)
• However, corrosion can occur when exposed to aggressive conditions
![Page 12: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/12.jpg)
What are the essential parts of a corrosion cell?
http://www.corrosion-club.com/images/corrosioncell.gif
Note: “Current” flows in the opposite direction as the “electrons” move.
ELECTROLYTE
METAL
![Page 13: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/13.jpg)
What are typical electrochemical half-cell reactions associated with the corrosion of steel in concrete?
• Anodic (oxidation) reaction
• Cathodic (reduction) reaction
2 21 2 2( )2
O H O e OH− −+ + →
2 2Fe Fe e+ −→ +
http://www.corrosion-club.com/images/corrosioncell.gif, http://www.tfhrc.gov
At the splash zone, corrosion can occur at a higher rate
![Page 14: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/14.jpg)
Corrosion of Steel in Water with Oxygen
Anode & cathode coexist on the same piece of metal !
Fe 2+
−+ +→ eFeFe 22
−− →++ OHeOHO 2221
22
Cathode
Anode
Fe(OH)2
2e- 2e-
Water
Iron
2OH -2OH -
Fe 2+
![Page 15: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/15.jpg)
Two major types of corrosion in concrete structures
• Carbonation-induced corrosion– General or uniform section loss
• Chloride-induced corrosion– Localized, pitting or non-uniform section loss
![Page 16: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/16.jpg)
Carbonation-induced corrosion
http://www.nbmcw.com/articles/concrete/others/493-carbonation-a-durability-threat-for-concrete.html
![Page 17: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/17.jpg)
Chloride-induced corrosion
Cl -
Flaws in passive layer and high chloride content
Pits growing at various locations
![Page 18: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/18.jpg)
Chloride-induced corrosion
• The process is regenerating and instead of spreading along the bar, corrosion continues at local anodes and deep pits are formed.
22e Fe Fe− ++ ←
−− →++ OHeOHO 2221
22
Concrete
Iron
Fe 2+ + 2Cl - → FeCl2
FeCl2 + 2H2O → 2HCl + Fe (OH)2
2H + + 2 Cl -
2e-
![Page 19: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/19.jpg)
Pitting corrosion on strands and deformed bars due to chloride attack
• 7-wire strand
• Deformed bar
![Page 20: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/20.jpg)
Typical locations for chloride induced corrosion and solutions?
http://is2c.nl/project-10979/moisture-and-salt-transport/
![Page 21: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/21.jpg)
Typical locations for chloride induced corrosion and solutions?
![Page 22: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/22.jpg)
A huge concern about the epoxy-coated steel
Courtesy: M. Thomas
It is more dangerous to use scratched/damaged epoxy-coated steel
than conventional uncoated steel
![Page 23: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/23.jpg)
Volume of rust is ~6 times more than that of steel
![Page 24: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/24.jpg)
Outline
• Significance of corrosion
• Corrosion mechanisms in concrete structures
• Corrosion monitoring in the field
• Ways to enhance and estimate service life
![Page 25: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/25.jpg)
How to detect corrosion in concrete structures?
• ASTM C876 Standard Test Method for Half-Cell Potentials of Uncoated Reinforcement in Concrete– If E < -0.35 V, 90% chance of corrosion – If E > -0.25 V, 90% chance no corrosion – If -0.35 V < E < -0.25 V, then ?
When using Cu/CuSO4reference electrode
Mehta and Monteiro
![Page 26: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/26.jpg)
Some commercially available equipment to detect corrosion using potential mapping
• Canin+
![Page 27: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/27.jpg)
Some commercially available equipment to measure corrosion rate
• GECOR6
Connection to reinforcement
Photo courtesy: James Instruments
![Page 28: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/28.jpg)
Linear polarization resistance and guard ring techniques to measure corrosion rate
Mehta and Monteiro
![Page 29: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/29.jpg)
Outline
• Significance of corrosion
• Corrosion mechanisms in concrete structures
• Corrosion monitoring in the field
• Ways to enhance and estimate service life
![Page 30: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/30.jpg)
The cost of corrosion is significant
• In 2012, the direct cost of corrosion in India was Rs. 2 lakhs crores/year!
FHWA 1998, George Hays 2004
A corrosion protection strategy to minimise the
repair and maintenance costs is a MUST
Corrosion cost split-up in the USA (FHWA 1998)
![Page 31: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/31.jpg)
Service life = the time during which the structure is able to safely meet the user requirements
Initiation PhasePropagation
PhaseRepair Phase
Maximum Allowable Damage Level
Lastrepair
Firstrepair
Overall Service Life
Time
Damage level • The corrosion initiation
phase is typically the longest phase in the service life of a structure
• Determining the duration of this phase is very important in determining a structure’s service life
![Page 32: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/32.jpg)
Core-crete StrengthCover-crete Durability
Cover-crete with low permeability is essential to achieve durability
![Page 33: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/33.jpg)
1. Rate of penetration (diffusion) of chlorides through covercrete (not corecrete)a) w/cb) SCMsc) SPs
2. Cover depth (covercrete)
3. Chloride threshold of steel
4. Chlorides at the surface of concrete
thresholdCl
Critical durability parameters
Cover depth
surfaceCl
![Page 34: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/34.jpg)
Adding excess water will reduce the strength and durability of concrete
Thomas and Bentz 2001, Life 365
w/c = low
w/c = high
![Page 35: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/35.jpg)
Adding SCMs will improve the strength and durability of concrete
H-S-C CH H SC SC hydroxide CalciumWaterCement
32 +→++
Concrete becomes stronger and less permeable when silica fume, fly ash and/or slag are added
H-S-C S SCMs
more→+
![Page 36: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/36.jpg)
Adding silica fume will improve the strength and durability of concrete
Thomas and Bentz 2001, Life 365
Pozzolanic reactions produce more C-S-H
![Page 37: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/37.jpg)
Adding fly ash and/or slag will improve the strength and durability of concrete y g
1E-13
1E-12
1E-11
1E-10
0.01 0.1 1 10 100
Age (years)
Diff
usio
n C
oeffi
cien
t, D
t (m
2/s
)
28 days
PC
30% SG
40% FA
Thomas and Bentz 2001, Life 365
m = 0.2 + 0.4(%FA/50 + %SG/70)
( ) refref
mtD t D
t
= ⋅
Pozzolanic reactions produce more C-S-H
![Page 38: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/38.jpg)
Critical chloride threshold levels of various steels
0
5
10
15
20
25
A706 A615 Microcomposite SS304 SS316
Crit
ical
Chl
orid
e Th
resh
old
Val
ue, (
lb/y
d3 ) Critical C
hloride Threshold Value, (kg/m
3)
15
12
9
6
3
0
Pillai and Trejo, 2005
![Page 39: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/39.jpg)
Tools are available to estimate the service life of concretes with various SCMs
http://www.life-365.org
![Page 40: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/40.jpg)
Effects of w/c and SCMs on service life
Case No. w/c Fly ash
(%)
Silica fume (%)
Time to corrosion initiation (years)
1 0.4 0 0 602 0.4 15 0 803 0.4 0 15 1804 0.6 0 0 405 0.6 15 0 506 0.6 0 15 100
Silica fume concrete was used in Bandra-Worli Sealink
![Page 41: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/41.jpg)
Life-365 software
![Page 42: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/42.jpg)
Life-365 software
![Page 43: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/43.jpg)
Life-365 software – probabilistic version
![Page 44: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/44.jpg)
Life-365 software
![Page 45: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/45.jpg)
Life-365 software
![Page 46: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/46.jpg)
Life-365 software
![Page 47: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/47.jpg)
Life-365 software
![Page 48: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/48.jpg)
Life-365 software – Results in tabular format
![Page 49: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/49.jpg)
Sensitivity of corrosion initiation time on input parameters
Slope ≈ 54o
Slope ≈ 30o
Slope ≈ -35o
Pillai and Annapareddy 2013
![Page 50: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/50.jpg)
Nomograph for estimating corrosion initiation time (based on Life-365 software)
Pillai and Annapareddy 2013
![Page 51: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/51.jpg)
Summary
• Significance of corrosion• Carbonation-induced corrosion• Chloride-induced corrosion
• Corrosion monitoring in the field
• Ways to enhance and estimate service life
![Page 53: Radhakrishna G. Pillai - The Concrete Portaltheconcreteportal.com/pillai.pdf · Reinforced Concrete Structures. Outline • Significance of corrosion • Corrosion mechanisms in concrete](https://reader030.fdocument.pub/reader030/viewer/2022020204/5ac2ab2b7f8b9ad73f8e6272/html5/thumbnails/53.jpg)
A great text book with an emphasis on the durability of concrete
With a lot of photos, videos, and lecture aids