Abstract

The curing time and compressive strength of ordinary Portland cement have its limitations, which limits its application range. In this article, the ratio of ordinary Portland cement/CSA ratio is optimized by laboratory test, and the composition and structure of hydration products are changed to achieve the performance adjustment. Then, the microstructures of the optimized cementing materials at different stages were observed and compared by the analysis of hydration process and scanning electron microscopy. The experimental results show that the setting time decreases with the increase of sulphoaluminate cement content in the system and prolongs with the increase of gypsum content, and the change trend of initial setting time and final setting time is consistent. When the content of sulphoaluminate cement exceeds 14% or the content of gypsum exceeds 16%, the compressive strength of cementing material decreases greatly in the early and late stages, but the strength of cementing material does not increase beyond this range. Composite admixtures H₃BO₃ (0.3%) + Na₂SO₄ (0.1%) and H₃BO₃ (0.3%) + NaNO₃ (0.1%) can not only improve the setting time of composite cementing materials, but also improve the strength of composite cement.

摘要

普通硅酸盐水泥的养护时间和抗压强度有其局限性，限制了其应用范围。本文通过室内试验优化普通硅酸盐水泥/CSA配比，改变水化产物的成分和结构，实现性能调整。然后，通过水化过程分析和扫描电镜分析，对优化后的胶结材料不同阶段的显微组织进行了观察和比较。试验结果表明，随着体系中硫铝酸盐水泥含量的增加，凝结时间减小，随着石膏含量的增加而延长，初凝时间和终凝时间的变化趋势是一致的。当硫铝酸盐水泥含量超过14%或石膏含量超过16%时，胶凝材料的抗压强度在前期和后期都有较大的下降，但超出此范围胶凝材料的强度不会增加。复合外加剂 H₃ BO ₃ (0.3%) + Na ₂ SO ₄ (0.1%)和H ₃ BO ₃ (0.3%) + NaNO ₃ (0.1%)不仅可以提高复合胶结材料的凝结时间，而且可以提高胶结材料的强度。复合水泥。