Effects of Relative Humidity and Temperature on the Transport of Chloride in the Concrete

  • Nam Jin-Gak (Florida Atlantic University) ;
  • Hartt William H. (Florida Atlantic University) ;
  • Kim Ki-Joon (Korea Maritime University)
  • Published : 2005.10.01


To investigate the role of RH and temperature on the transport of chloride in the concrete, two groups of specimens were configured. For both groups, mix design was based on w/c=0.45, $400kg/m^3$ cement, $794kg/m^3$ fine aggregate and $858kg/m^3$ coarse aggregate. After specimen fabrication these were exposed to four different RH (35, 55, 75 and $95\%$ RH) and temperature (0, 20, 30 and $40^{\circ}C$) conditions. After 3 and 6 months $15\%$ NaCl exposure 5mm cores were taken. These cores were sliced and individual cores were ground to powder. In addition, to evaluate the effect of temperature on the chloride binding some powder samples were leached in the each of four temperature chambers. Chloride titration fur these was performed using FDOT acid titration method. Based upon the resultant data conclusions were reached regarding that 1) effective diffusion coefficient, $D_e$, increased with increasing exposure RH, suggesting that the size and number of water paths increased with elevated moisture content in the specimens, 2) $D_e$ increased with increasing temperature in the range of 0 to $40^{\circ}C$ possibly by elevated thermal activation of chloride ions and reduced chloride binding at higher temperature, 3) water soluble chloride concentration, $[Cl^-]_s$, increased with increasing temperature, and 4) chloride concentration profile for initially dry concrete specimens was higher than for the initially wet ones indicating pronounced capillary suction (sorption) occurred for the dry concrete specimens.


  1. L. Tang, 'Concentration Dependence of Dilfusion and Migration of Chloride Ions Part l.Theoretical Considerations,' Cement and concrete research, Vol.29, 1999, pp. 1463-1468
  2. J. Nam, W. Hartt, K.Kim, and L. Li, 'Effect of Cement Alkalinity upon Time-to-Corrosion of Reinforcing Steel in Concrete Undergoing Chloride Exposure,' paper no.03299, CORROSION/2003
  3. P. B. Bamforth, Definition of Exposure Classes and Concrete Mix Requirements for Chloride Contaminated Environments, Corrosion of Reinforcement in Concrete, Eds: Page, C.L., Treadaway, K.W.J., and P. B. Bamforth, Soc. Chem. Ind., London, 1996, pp. 176.
  4. P. B. Bamforth and W. F. Price, Factors Influencing Chloride Ingress into Marine Structures, Concrete 2000, Eds: R. K. Dhir and M. R. Jones, E&FN Spon, London, 1993, pp. 1105
  5. E. C. Bentz, C. M. Evans and M. D. A. Thomas, Chloride diffusion modeling for marine exposed concretes, Department of Civil Engineering, University of Toronto. Ontario, Canada, M5S lA4
  6. M. D. A. Thomas and P. B. Bamforth, 'Modeling Chloride Diffusion in Concrete: Effects of fly Ash and Slag,' Cement and Concrete Composites, Vol.29, 1999, pp. 487-495
  7. M. R. Jones, R. K. Dhir, and J. P. Gill, 'Concrete Surface Treatment: Effect of Exposure Temperature on Chloride Diffusion Resistance,' Cement and Concrete Research, Vol.25, No 1, 1995, pp. 197-208
  8. Waheeb A. Al-Khaja, 'Influence of Temperature, Cement Type and Level of Concrete Consolidation on Chloride Ingress in Conventional and High-Strength Concretes,' Construction and Building Materials, Vol. 11, 1997, pp.9-13
  9. R. Luoa., Y. Caib, C. Wangb, and X. Huang, 'Study of Chloride Binding and Diffusion in GGBS Concrete,' Cement and Concrete Research, Vol.33, 2003, pp 1-7
  10. C. Andrade, J. M. Diez, and C. Alonso, 'Modeling of Skin Effects on Diffusion Process in Concrete,' RILEM, 1997, pp.182-194
  11. C. Andrade, J. M. Diez and C. Alonso, Mathematical Modeling of a Concrete Surface 'Skin Effect' on Diffusion in Chloride Contaminated Media, Advanced Cement Base Material, 1997, pp.39-44
  12. J. Z. Zhang, I. M. McLoughlin, and N. R. Buenfeld, 'Modeling of Chloride Diffusion into Surface-Treated Concrete,' Cement and Concrete Composites, Vol .20, 1998, pp.253-261
  13. P.A.M. Basheer and E. Nolan, 'Near-Surface Moisture Gradients and In Situ Permeation Tests,' Construction and Building Materials, Vol.15, 2001, pp.105-114
  14. N. S. Martys, and C. F. Ferraris, 'Capillary Transport in Mortars and Concrete,' Cement and Concrete Research, Vol 27, No.5, 1997, pp.747-760
  15. A. Buchwald, 'Determination of the Ion Diffusion Coefficient in Moisture and Salt Loaded Masonry Materials by Impedance Spectroscopy,' Third International PhD Symposium, Vienna, Vol.2, Oct 2000, pp. 475-82
  16. C. K. Larsen, Effect of Type of Aggregate, Temperature. and Drying/Rewetting on Chloride Binding and Pore Solution Composition,' RILEM, 1997, pp.27-35
  17. P. Thoft-Christensen, Deterioration of Concrete Structure, First International Conference on Bridge Maintenance, Barcelona, July 2002
  18. Sampling and Testing for Chloride Ion in Concrete and Concrete Raw Materials, Designation T 260-94, American Association of State Highway and Transportation Officials
  19. The Florida Method of Test for Determining Low Level of Chlorides in Concrete and Raw Materials, designation FM 5-516, Florida Department of Transportation
  20. P.A.M. Basheer and E. Nolan, 'Near-Surface Moisture Gradients and In Situ Permeation Tests,' Construction and Building Materials, Vol.15, 2001, pp.105- 114
  21. J. K. Kim and C. S. Lee, 'Moisture Diffusion of Concrete Considering Self-Desiccation at Early Ages,' Cement and Concrete Research, Vol.29, 1999, pp. 1921-1927