Journal of Failure Analysis and Prevention

, Volume 10, Issue 3, pp 169–177 | Cite as

Characterization and Mathematical Modeling of Chloride Diffusion in Lagos Coastal Waters

  • A. A. Akindahunsi
  • F. A. Falade
  • J. O. Afolayan
  • I. A. Oke
Feature

Abstract

Reports and news on failure due to corrosion degradation of structures in aggressive environments are common occurrences in literature nowadays. This paper presents deterioration pattern of concrete structures in a coastal environment and effects chloride concentration on the steel reinforcements in concrete as a way towards failure control: water samples were collected from coastal environments (Tin Can Island and Bar Beach, Lagos, Nigeria). Laboratory analyses were carried out to determine the chloride contents and values obtained for the chloride concentrations were used to prepare different concentrations of chloride solutions to be used as aggressive curing environments. The test blocks were connected in parallel to a D.C rectifier set at 10 V to accentuate the rate of corrosion. A Half-Cell potential apparatus was used to determine the corrosion potential at intervals of 4 days for a period of 28 days after the initial 28 days of curing. A simple statistical model that relates chloride concentrations to the strength of the concretes was developed and tested. The study revealed that chloride concentration has significant effect on reinforcement. Rebar in 24878.80 mg/L curing tank was the most affected by corrosion with potential reading of 466.50 mV and the rebar in this block was not able to sustain any tensile load. The model developed described the strength of the concretes with correlation coefficient R 2 higher than 0.950 (R 2 > 0.950).

Keywords

Reinforcing bars Chloride concentrations Corrosion Tensile stress Model correlation 

Notations

Ji

Flux of the ion I (mol m−2 s−1)

Di

Diffusion coefficient (m2 s−1)

Ci

Concentration (mol m−3)

zi

Valence of the ion

F

Farady’s constant (C mol−1)

R

Gas constant (J K mol−1)

T

Temperature (K)

ϕ

Electric potential (V)

Ic

Current density (A m−2)

P

Porosity

ρ

Density of the material (kg m−3)

Bi

Quantity bound species (mol kg−1)

CuSO4

Copper sulphate

References

  1. 1.
    Caré, S., Raharinaivo, A.: Influence of impressed current on the initiation of damage in reinforced mortar due to corrosion of embedded steel. Cement Concr. Res. 37, 1598–1612 (2007)CrossRefGoogle Scholar
  2. 2.
    Akindahunsi, A.A.: A study of Concrete Degradation in the Coastal Environment Lagos, Nigeria. An unpublished M.Phil. Thesis submitted to the Postgraduate College of Obafemi Awolowo University Ile-Ife, Nigeria (2008)Google Scholar
  3. 3.
    Jensen, O.M., Hansen, P.F., Coats, A.M., Glasser, F.P.: Chloride ingress in cement paste and mortar. Cement Concr. Res. 29, 1497–1504 (1999)CrossRefGoogle Scholar
  4. 4.
    Olajumoke, A.M., Oke, I.A., Fajobi, A.B., Ogedengbe, M.O.: Engineering failure analysis of a failed building in Osun State, Nigeria. J. Fail. Anal. Preven. 9, 8–15 (2009)CrossRefGoogle Scholar
  5. 5.
    Toumi, A., François, R., Alvarado, O.: Experimental and numerical study of electrochemical chloride removal from brick and concrete specimens. Cement Concr. Res. 37, 54–62 (2007)CrossRefGoogle Scholar
  6. 6.
    Sugiyama, T., Ritthichauy, W., Tsuji, Y.: Experimental investigation and numerical modeling of chloride penetration and calcium dissolution in saturated concrete. Cement Concr. Res. 38, 49–67 (2008)CrossRefGoogle Scholar
  7. 7.
    Potgieter, S.S., Marjanovic, L.: A further method for chloride analysis of cement and cementitious materials — ICP-OES. Cement Concr. Res. 37, 1172–1175 (2007)CrossRefGoogle Scholar
  8. 8.
    Conciatori, D., Sadouki, H., Brühwiler, E.: Capillary suction and diffusion model for chloride ingress into concrete. Cement Concr. Res. 38, 1401–1408 (2008)CrossRefGoogle Scholar
  9. 9.
    Swatekititham, S.: Computational model for chloride concentration at surface of concrete under actual environmental condition. A dissertation submitted to Kochi University of Technology in partial fulfillment of the requirements for the degree of Doctor of Engineering Infrastructure, Kochi, Japan (2004)Google Scholar
  10. 10.
    APHA: Standard Method for the Examination of Water and Wastewater, 20th edn. America Water Works Association and Water Pollution Control federation, Washington DC (1998)Google Scholar
  11. 11.
    British Standard Code of Practice BS 8110, 1997, Part 1. The Structural Use of Concrete, Her Majesty Stationary Office, LondonGoogle Scholar
  12. 12.
    ASTM C876. Obtaining effective half-cell potential measurements in reinforced concrete. irc.nrc-cnrc.gc.ca/pubs/ctus/18_e.html-31k. Date accessed June 2, 2007 (1999)
  13. 13.
    Oluwadare, G.O., Akindahunsi, A.A., Oluwole, O., Agbaje, I.A.: Effects of Cassava juice on corrosion of mild and high yield steel bars in concrete structures. Niger. Soc. Eng. Techn. Trans. 44(2), 46–56 (2009)Google Scholar
  14. 14.
    Akindahunsi, A.A., Falade, F.A., Afolayan, J.O., Oke, I.A.: Effects of chloride salt on reinforced concrete structures in Lagos Coastal Environment. J. Eng. Res. Accepted for publication (2009)Google Scholar
  15. 15.
    Bucea, L., Khatri, R., Sirivivatnanon, V.: Chemical and physical attack of salts on concrete. UrbanSalt 2005 Conference Riverside Theatre, ParramattaGoogle Scholar
  16. 16.
    Prasad, J., Jain, D.K., Ahuja, A.K.: Factors influencing the sulphate resistance of cement concrete and mortar. Asian J. Civil Eng. (Building and Housing) 7(3), 259–268 (2006)Google Scholar
  17. 17.
    Sadiq, O.M., Akpan, A.J., Musa, O.A.: Strength evaluation of concrete in chemically aggressive environment Nigerian Society of Engineers. Tech. Trans. 31(2), 80–86 (1996)Google Scholar

Copyright information

© ASM International 2010

Authors and Affiliations

  • A. A. Akindahunsi
    • 1
  • F. A. Falade
    • 1
    • 2
  • J. O. Afolayan
    • 1
    • 3
  • I. A. Oke
    • 1
  1. 1.Department of Civil EngineeringObafemi Awolowo UniversityIle-IfeNigeria
  2. 2.Department of Civil and Environmental EngineeringUniversity of LagosLagosNigeria
  3. 3.Department of Civil EngineeringFederal University of TechnologyAkureNigeria

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