Effect of Low Temperatures on the Resistance of Steel Fiber–Reinforced Rubberized Concrete against Chloride Erosion

Low-temperature climate in extremely cold regions can pose significant challenges to the durability of concrete. In this study, artificially simulated chloride dry–wet cycle tests were performed on 25 groups of steel fiber–reinforced rubberized concrete (SFRRC) cubic specimens, which were subjected to low temperatures (0°C, −20°C, −40°C, and −60°C) to ambient temperature (20°C) cycling. Additionally, 50 groups of plain concrete (PC) and rubberized concrete (RC) cubic specimens subjected to the same treatment were provided as controls. The distribution of free chloride content within the PC, RC, and SFRRC specimens was measured and determined. Three key parameters (convection zone depth, peak free chloride content, and chloride diffusion coefficient) for evaluating chloride erosion resistance of SFRRC were calculated. Furthermore, a time-dependent predictive model for the free chloride content in SFRRC was developed, taking into account the effects of low temperatures. The experimental results indicated that the chloride erosion resistance of PC and RC were negatively impacted by the effect of low temperatures. However, the incorporation of steel fibers can effectively mitigate the adverse effects of low temperatures on the chloride erosion resistance of SFRRC, resulting in reductions of 10.6%, 14.3%, and 13.9% in convection zone depth, peak free chloride content, and chloride diffusion coefficient, respectively, compared to RC. The proposed model in this study can provide accurate predictions of the chloride erosion resistance of SFRRC in extremely cold regions.