Deterioration Performance of Recycled Aggregate Pervious Concrete under Freezing–Thawing Cycle and Chloride Environment

To study the performance of recycled aggregate pervious concrete (RAPC) in severe cold regions, the influence of the water–binder ratio, design porosity, micro silica fume (SF) and enhancer agent (EA) on the permeability and mechanical properties of the RAPC were evaluated using the orthogonal design method. Based on the optimal mixture proportion, freeze–thaw (F-T) experiments were carried out to investigate the effect of different media (water, 3.5 wt% NaCl solution) on the mechanical properties, permeability and anti-frost durability of the RAPC. Moreover, the porosity and pore structure characteristics of RAPC were evaluated after frost damage using an X-ray CT technique. The results indicate that the influence of the salt solution on the deterioration of the RAPC specimen is greater than water. The deterioration degree of the mass loss ratio, relative dynamic elastic modulus (RDEM), average compressive strength and porosity of the RAPC increase with increasing F–T cycles. Based on the two-parameter Weibull probabilistic distribution function, damage evolution models of RAPC are established, which can be used to quantitatively characterize the damage degree of the RAPC specimens under different F–T media. The results obtained can provide an experimental reference and data support for the promotion and application of RAPC pavement in severe cold regions.