Investigation of Cement Mortars Added Silicon Carbide Under Various Hydrochloric Acid Exposure Conditions

Abstract

In this study, the effects of silicon carbide (SiC) addition on the properties of cement mortars subjected to hydrochloric acid (HCl) exposure were evaluated. The primary objective was to assess the mechanical performance and durability enhancement of cement mortars incorporating SiC under aggressive acidic conditions. Cement mortars were prepared by replacing aggregates with SiC at ratios of 0%, 5%, 10%, and 15%, and were exposed to 10% HCl solution under three distinct environmental conditions: continuous immersion in acid, alternating periods in air, and water exposure. To evaluate acid resistance, the mass and compressive strength losses of the mortar specimens were measured before and after acid exposure. Additionally, micro-computed tomography (micro-CT) was conducted to examine internal microstructural changes. Results from mechanical tests and micro-CT analysis revealed that the incorporation of SiC significantly reduced the degradation of the cement matrix by densifying the microstructure and lowering porosity, thereby enhancing resistance to acid attack. These findings suggest that SiC can serve as an effective additive for improving the durability of cementitious materials in acidic environments.