Steel slag (SS) is a by-product of the steel industry, and its recycling is of great significance. In this study, the influence of SS fineness and curing regimes on the hydration properties of cement and the effects of SS content on the compressive strength of pastes were investigated. The hydration products and microstructure of pastes were further explored through X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that the compressive strength decreases gradually with the increase of SS, and increases with the increase of the specific surface area of SS. The compressive strength of paste after steam curing is improved, and the compressive strength of the paste mixed with 30% SS can reach more than 50 MPa after 90 days of steam curing. The hydration products of paste mixed with SS are not significantly different from those of cement, which mainly comprise calcium hydroxide (Ca(OH)₂) and calcium silicate hydrate (C–S–H) gel, accompanied by a small amount of calcium carbonate (CaCO₃). SS has secondary hydration after long-term ageing and can fill and refine the pore structure, according to SEM. Using SS as a supplementary material is beneficial in terms of reducing cement cost and lowering carbon dioxide (CO₂) emission.

中文翻译：

---

蒸汽养护条件下含钢渣复合胶凝材料的水化性能

钢渣（SS）是钢铁工业的副产品，其回收利用具有重要意义。在这项研究中，研究了SS细度和养护方式对水泥水化性能的影响以及SS含量对浆体抗压强度的影响。通过 X 射线衍射 (XRD) 和扫描电子显微镜 (SEM) 进一步探讨了糊剂的水化产物和微观结构。结果表明，抗压强度随着SS的增加而逐渐降低，随着SS比表面积的增加而增加。蒸汽养护后膏体的抗压强度得到提高，掺入30%SS的膏体在蒸汽养护90天后抗压强度可达到50MPa以上。掺SS的浆体水化产物与水泥无明显差异，主要成分为氢氧化钙（Ca(OH) ₂）和水化硅酸钙（C-S-H）凝胶，并伴有少量碳酸钙(CaCO ₃ )。扫描电镜观察发现，SS经过长期老化后具有二次水化作用，可以填充和细化孔隙结构。使用SS作为辅助材料有利于降低水泥成本和减少二氧化碳(CO ₂ )排放。