Hydration activity and mechanical properties of steel slag used as cementitious materials

Abstract The massive steel slag not only occupies land resources but also pollutes the environment, so it is necessary to efficiently utilize steel slag. In this article, the hydration activity and mechanical properties of steel slag used as cementitious materials were studied. Results showed the steel slag was difficult to hydrate at room temperature within 3 days. After the steel slag was autoclaved at 215°C, 2 MPa for 3 h, its hydration degree was 1/3 of that of Portland cement. The expansion rate of the steel slag‐cement cementitious materials increased linearly with the increase of steel slag content. When the content of steel slag was 60%, the specimen was cracked under boiled conditions and pulverized under autoclaved conditions. The strength of mortar first increased and then decreased with the increase of steel slag content. When the content of steel slag was 10%, the mortar produced the highest 28‐day compressive strength of 49.01 MPa and flexural strength of 8.78 MPa.