Effect of ambient chloride concentration in environment on peak chloride concentration and its randomness of concrete

Based on long‐term field exposure tests, the effects of exposure environment, exposure time and material composition on the time‐varying process and the randomness of the mean peak chloride concentration of eight different concrete mixtures in two natural tidal environments were studied. A method was proposed for analyzing the randomness of peak concentrations in concrete while accounting for time‐varying behavior and the corresponding probability distributions of the probability density functions for peak concentrations under two different environments were obtained. Subsequently, the similarity of time‐varying functions of the mean peak chloride concentrations under two environments was analyzed, and the similarity of their random distribution was investigated using the Kullback–Leibler divergence method. Results show that with the increasing ambient concentration in environment and exposure time, both the chloride concentration and peak chloride concentration of concrete increase. The ambient concentration has a more significant effect on chloride concentration, peak chloride concentration, and the corresponding time‐varying process than the exposure time and material composition. The peak chloride concentrations under two environments both follow the normal distribution. Chloride concentration in ambient environment has a limited influence on the random distribution type of maximum chloride concentration, but it does influence the corresponding statistical parameters. Moreover, the degree of randomness increases with increasing chloride concentration in the ambient environment. The time‐varying trends of the mean peak chloride concentrations in concrete are similar under both environmental conditions. Based on the difference in chloride concentrations in the surrounding water, it is possible to infer the time‐dependent trends of peak chloride concentrations in concrete under environmental conditions with similar climates but different water chloride concentrations. Probability distribution functions of the peak chloride concentrations in two different environments show a high degree of similarity in the later exposure stage. The variable () proposed in this paper to describe the randomness of peak concentrations is more appropriate for characterizing peak concentrations, and the similarity is even higher in the later stages of exposure.