A PREDICTION METHOD FOR LONG-TERM CHLORIDE CONCENTRATION PROFILES IN HARDENED CEMENT MATRIX MATERIALS

A method to predict long-term chloride concentration profiles in 100 p ercent ordinary portland cement (OPC) paste, mortar and concrete with water-cement ratios in the range of 0.4 to 0.6 is presented. This appr oach of using the semi-empirical models enables an engineer who perfor ms core sampling to predict the future chloride concentration profile of concrete structures in the submerged zone. The variation in chlorid e binding, with respect to the amount of cement hydrates available as a function of-time and with respect to the amount of free chloride ion s present as a function of distance from the surface, is also incorpor ated in the modeling so that the mechanisms of chloride ingress are be tter represented. Good correlation is observed between analytical resu lts obtained based on the proposed method and experimental data report ed in the literature. This confirms the applicability and reliability of the proposed prediction method.