Study on the frost resistance durability of recycled aggregate concrete under an extreme cold environment

Recycled aggregate concrete (RAC), as a way to reuse waste concrete, is good for solving environmental and resource problems. In this paper, the frost resistance durability of RAC under an extreme cold environment was studied, RAC specimens with different replacement rates were designed, and then the indexes of the specimens, such as mass loss rate, were calculated and compared. It was found that with the progress of the freeze-thaw cycle, the higher the replacement rate of recycled concrete aggregate (RCA) was, the worse the frost resistance durability was. The mass loss rate of RAC-3 (100% RCA replacement rate) was 5.56%, the strength loss rate was 40.86%, and the relative dynamic elastic modulus was 61.89%, all of which were significantly lower than that of RAC-0. The experimental results verify that the excessively large replacement rate of RCA is not conducive to the frost resistance durability of concrete. The replacement rate of RCA needs to be paid attention to when used in an extremely cold environment.