Abstract:Four kinds of coal gangue, which were sampled from Dongsheng(D CG), Xuejiawan(X CG), Wuhai(W CG) and the aggregate from practical road construction(AGG), were immersed in different acid solutions to simulate acid rain in lab. The pH values of the immersion solutions were measured and mass loss rate of the coal gangue was calculated after immersion. XRD and shear strength tests were used to measure the change of chemical composition and strength of the coal gangue. The results show that the effect of soaking time, ratio of solid to liquid, chemical constituents of the coal gangue, and acidity of soaking solution on the pH value is significant. Immersed in acid solution, pH values of D CG and AGG increase, X CG and W CG decrease, while immersed in neutral solution, pH values of D CG, X CG and W CG decrease more than that of AGGs. The mass loss rate of the coal gangue in acid solutions is higher than that in neutral solution. The strength of the coal gangue in acid solutions is lower than that in neutral solution. The results of XRD spectrum indicate that the structure and mineral constituent of samples are decomposed and the crystal structures are damaged in acid solutions, with the result that mass loss rate of the coal gangue increases.