Abstract: To address the challenge of steel slag disposal, characterized by large quantities and low utilization rates, we prepared a green, low-carbon cement-based material with optimized mechanical properties by substituting part of the cement with steel slag ground into micro-powder and combined with silica fume. We conducted experimental studies on the rheological behavior, early hydration exotherm, strength, and water absorption of the prepared composite cement-based material system at various proportions. Our key findings are as follows: 1) Steel slag powder particles exhibits a less angular and flaky micro-morphology. When replacing 15% of the cement, steel slag powder effectively enhances matrix consistency, slightly reduces strength, and significantly decreases early hydration heat release by 8.8%, which is beneficial to the control of early temperature-induced cracking.2) Incorporating silica fume notably decreases the material’s plastic viscosity and pumping pressure. For applications requiring long-distance pumping, such as mass concrete or high-performance concrete, silica fume content should be limited to 5%. Additionally, silica fume’s space-filling effect and pozzolanic reaction enhances the material’s compactness and substantially improves strength. In summary, cement-based material incorporating 15% steel slag powder and 5% silica fume not only enhances pumping performance, strength, and durability but also mitigates early hydration heat release, demonstrating promising engineering applications.

Key words: steel slag powder, silica fume, rheology, early hydration heat, strength, water absorption