EROSION RESISTANCE OF PRE-TREATED RICE HUSK ASH CONCRETE UNDER SIMULATED ACID RAIN

In order to explore the ability of pre-treated rice husk ash concrete to resist acid rain erosion, this study investigates the deterioration law of ordinary concrete and pre-treated rice husk ash concrete under the combined action of acid rain erosion and dry-wet cycles, combining microscopic changes and a series of indicators such as the compressive strength of the concrete, with the dry-wet cycle of clean water as a control to analyse the deterioration law of the concrete. The results show that when the replacement rate of the pre-treated rice husk ash is 10%, the compressive strength of the concrete is the most improved and the splitting tensile strength is negatively correlated with the substitution rate of P-RHA. From the durability of the concrete, with the progress of the dry-wet cycle, the mass, compressive strength, and relative dynamic elasticity modulus show a decreasing trend, and the water absorption shows an upward trend. According to microscopic changes, the two types of concrete are mainly eroded by gypsum. The addition of P-RHA can promote the growth of C-S-H gels, reduce the effective porosity of the concrete, and delay the deterioration time of the concrete. By analysing the depth of the degradation of the concrete′s compressive strength, it is concluded that the ordinary concrete is destroyed earlier than the P-RHA concrete.