Properties and Hydration Mechanism of Lime-Based Slag‑Steel Slag Composite Cementitious Materials

To analyze the properties and hydration mechanism of lime‑based slag‑steel slag composite cementitious materials,discussions are conducted on the mechanical properties and working performance of the composite cementitious materials with different steel slag and lime mass fraction. Furthermore,detection methods such as XRD are employed to explore the hydration mechanism of the composite cementitious materials. The research results indicate that the optimal steel slag content in lime‑based slag‑steel slag composite cementitious materials is 30%. The compressive strength is 32. 3 MPa after 28 d of maintenance. The primary hydration products of the composite cementitious materials are C-(A)-S-H gel,hydrocalumite, Ca(OH)2,and calcite,among which the interlocking C-(A)-S-H gel provides the primary compressive strength for the composite cementitious materials. When the steel slag content in the composite cementitious materials ranges from 20% to 30%,it does not significantly affect the formation of C-(A)-S-H gel in the cementitious materials and can promote the hydration of slag. An appropriate amount of steel slag exhibits a filling effect,reducing microcracks in the composite cementitious materials, making the matrix more compact, and enhancing the mechanical properties of the composite cementitious materials. © 2024 Northeast University. All rights reserved.