钢渣-矿渣基胶凝材料的协同水化机理

Synergistic Hydration Mechanism of Steel Slag‑Slag Based Cementitious Material

通过胶砂强度试验及X射线衍射仪(XRD)、热失重分析(TG-DTG)、扫描电镜-能谱仪(SEM-EDS)等微观测试技术,对不同配合比钢渣-矿渣基胶凝材料的力学性能、水化产物及其水化硬化过程进行了研究.结果表明:当胶凝材料的n(CaO+MgO)/n(SiO2+Al2O3)=0.90时,其水化后期有较多的水化硅酸钙、水化铝酸钙凝胶生成,微观结构更加致密,力学性能表现最优,28 d抗压强度和抗折强度分别达到20.20、7.25 MPa;pH值的变化反映出协同水化效应的关键在于钢渣活性矿物的溶解和矿渣的二次火山灰反应,钢渣和矿渣的最佳配合比可以保证水化程度有较高的水平.

The mechanical properties,hydration products and hydration hardening processes of steel slag-slag based cementitious materials with different mix proportion were investigated using mortar strength tests and microscopic testing techniques such as X-ray diffraction(XRD),thermogravimetric analysis(TG-DTG)and scanning electron microscopy-energy dispersive spectroscopy(SEM-EDS).The results show that when n(CaO+MgO)/n(SiO2+Al2O3)is 0.90,more hydrated calcium silicate and hydrated calcium aluminate gels are generated in the later stage of hydration,the microstructure is more dense and the mechanical properties are the best.The compressive and flexural strength reach 20.20,7.25 MPa at 28 days.The changes in pH value show the synergistic effect of hydration resulting from the dissolution of active minerals in steel slag and the occurrence of secondary fly ash reactions in slag.The optimal mix proportion of steel slag and slag ensures a higher level of hydration.