Deterioration characteristics of recycled aggregate concrete subjected to coupling effect with salt and frost

In this study, the comprehensive performance and material properties of recycled aggregate concrete (RAC) under the coupled effect of salt-frost cycles were investigated to simulate the effect of complex environmental effects on the durability and deterioration of RAC. The tests on mass loss, relative dynamic modulus of elasticity (RDME), and compressive strength of RAC were conducted after 0, 25, 50, 75, and 100 standard salt-frost cycles. The results show that the mass loss, RDME, and compressive strength of RAC develop in a bad direction with the increase of the number of salt-frost cycles and the amount of recycled aggregate admixture. The concrete damage is particularly severe at more than 40% recycled aggregate admixture. This phenomenon is explained by the changes in the microscopic morphology, distribution of the pore structure, and functional groups of RAC.