To understand the degradation of mechanical properties of recycled aggregate concrete(RAC) after acid rain exposure, the effect of recycled coarse aggregate (RCA) replacement ratios, the acidity (pH value) of the simulated acid rain solution and mineral admixtures on compressive strength and elastic modulus of RAC are investigated in this study. The test results showed that elastic modulus and the compressive strength of RAC specimens may increase slightly at the beginning of acid rain spraying, then decreases gradually with the continuous erosion of acid rain. The greater the acidity of acid rain solution is, the more obviously the mechanical properties of RAC decreases. Appropriately adding fly ash and silica fume separately or together will effectively improve the strength and the acid rain resistance of RAC, whereas higher replacement rate of RCA may be unfavourable for RAC to resist acid rain. SEM/EDS observation and analyses also further illustrated that the impact of acid rain and mineral admixtures on the microstructures of ITZ in RAC.

为了了解酸雨暴露后再生骨料混凝土（RAC）的机械性能的下降，再生粗骨料（RCA）置换比例，模拟酸雨溶液和矿物掺合料的酸度（pH值）对抗压强度和在这项研究中研究了RAC的弹性模量。试验结果表明，在酸雨喷涂开始时，RAC试样的弹性模量和抗压强度可能会略有增加，然后随着酸雨的持续侵蚀而逐渐降低。酸雨溶液的酸度越大，RAC的机械性能下降越明显。分别或一起添加粉煤灰和硅粉将有效提高RAC的强度和耐酸雨性，然而，RCA的更高置换率可能不利于RAC抵抗酸雨。SEM / EDS观察和分析还进一步表明，酸雨和矿物混合物对RAC中ITZ的微观结构的影响。