Effect of highly reactive carbonated steel slag on hydration and mechanical properties of cement composites

Abstract

钢渣(SS)的低水化活性限制了其作为辅助胶凝材料(SCMs)的应用潜力，本文通过碳化将钢渣转化为具有高活性的碳化钢渣(CS),并系统研究了CS对水泥基复合材料水化过程和力学性能的影响规律。结果表明，CS显著促进了水泥的水化反应，增大了凝结速率，并显著提高了水泥基复合材料的抗压强度。当CS掺量为20%(质量分数)时，水泥基复合材料的1和28 d抗压强度相比对照组分别提升约0.9%和14.4%。CS对水泥基复合材料水化过程及力学性能的改善主要归因于CS具有的高活性硅凝胶和碳酸钙，这些成分加速了水化产物的生成。此外，CS中存在的超细颗粒发挥了填充效应，增强了微观结构的致密性，从而有效提高了抗压强度。 The low hydration reactivity of steel slag ( SS) significantly limits its application as supplementary cementitious materials ( SCMs) . In this study, SS was converted into carbonated steel slag ( CS) with high activity by carbonization, and the effect of CS on the hydration process and mechanical properties of cement composites was systematically studied. The results show that CS markedly accelertes the cement hydration reaction, enhances the setting rate, and substantially enhances the compressive strength of cement composites. When the CS content is 20% ( mass fraction) , the compressive strength of the cement composite increases by approximately 0. 9% and 14. 4% compared with the reference sample at 1 and 28 d, respectively. The enhancement in hydration process and mechanical properties of cement composites with CS is primarily attributed to the highly reactive silica gels and calcium carbonate, which accelerate the formation of hydration products. In addition, the ultrafine particles in CS play a filling effect and enhance the compactness of the microstructure, thus effectively improving the compressive strength.