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本工作用化学法、超声法、X-射线分析法、热分析法以及电子显微镜观察等方法研究了酒石酸和CMC对C_3和C_3A的水化凝结机理,认为酒石酸主要通过提高水—C_3S高分散体系的动力稳定性使C_3S浆缓凝,CMC使C_3S浆体缓凝主要是由于水泥颗粒和新生成物表面吸附CMC大离子团而形成了保护膜的结果。因此酒酸对C_3S的缓凝作用较CMC显著得多,且能提高强度。酒石酸使C_3A促凝的原因是胶状新相的形成以及酒石酸极性分子促进铝胶的聚沉,CMC对C_3A的促凝作用是由于带负电的大离于团使水化体内铝胶聚沉加速。 在探讨缓凝机理的基础上,论文最后对缓凝水泥的矿物组成和缓凝剂的选择,以及有机外加剂对硅酸盐水泥的缓凝作用等问题提出了看法。
In this work, the mechanism of hydration condensation of C_3 and C_3A by tartaric acid and CMC was studied by chemical method, ultrasonic method, X-ray analysis, thermal analysis and electron microscopy. It was considered that tartaric acid mainly improves the water-C 3 S dispersion system. The dynamic stability of the C3S slurries is retarded, and the CMC causes retardation of the C3S slurries mainly due to the formation of a protective film due to the adsorption of CMC large ion clusters on the surface of the cement particles and new products. Therefore, the retardation of C 3 S by sour acid is much more significant than that of CMC, and it can increase the strength. Tartaric acid causes the coagulation of C_3A to be caused by the formation of a new gelatinous phase and the polar molecules of tartaric acid to promote the aggregation of aluminum colloids. The procoagulant action of CMC on C_3A is due to the large negatively charged group leaving the aluminum colloids in the hydration body. accelerate. On the basis of discussing the mechanism of retardation, the paper finally put forward the opinions on the mineral composition of retardative cement, the selection of retarder, and the retarding effect of organic admixture on Portland cement.