Purpose This study aims to investigate the effect of temperature alternation on the chloride threshold (CT) of rebar. Design/methodology/approach CT of rebar was determined by step-by-step addition of chloride ions in a pore solution at different constant and alternating temperatures. A new model, which simultaneously considered the average temperature and the amplitude of temperature change, was proposed to predict the CT of rebar in concrete structures at alternating temperatures. Findings CTs significantly decreased with the temperature and the amplitude of temperature change at the former and the latter conditions, respectively. The high temperature was the determining factor for the CT of the rebar when the alternating temperatures had the same average temperature. Practical CTs of marine concrete structures were adopted to check the model, and the results suggested that the new model can effectively predict the CT values of rebar in concrete structures under alternating temperature conditions. Originality/value This research may provide a new method to accurately measure the CT of reinforcement when the concrete structure serves in a high-amplitude temperature alternation environment.
Feng et al. (Tue,) studied this question.