Evaluation of sulfate resistance of cement mortars with the replacement of fine stone powder

In this study, fine stone powder (FSP) generated in the process for producing crushed coarse and fine aggregate was used as a partial replacement for the fine aggregate. The durability of mortars was investigated under sulfate attack in terms of compressive strength loss, change in mass, and expansion. Cement mortars were made with the replacement rate of 0–30% of FSP for fine aggregate with two water-to-cement ratios of 48.5% and 58.5%. The prepared mortar specimens were immersed in 5% sodium and magnesium sulfate solutions for 365 days, and the changes in strength, mass, and length due to sulfate attack were estimated and compared according to ages (days). The strength loss rate of the specimen made with 15% FSP replacement immersed in sulfate solutions was less than the controlled specimen and the higher amount of FSP than 15% resulted in a significant strength loss. At the replacement level of 15% FSP, the mass loss and expansion were also less than that of the controlled specimen. The results illustrate that replacing the appropriate amount of FSP can improve the strength and sulfate resistance. In addition, it could be seen that the magnesium sulfate solution caused a more severe attack than the sodium solution.