Investigation On Portland-Type Cements Early Hydration Characteristics And Their Relations

According to Portland-type cement hydration characteristics, experiments of chemically bound water, paste conductance, conductance and pH of water-cement suspension, hydration heat, insoluble residua of cement, particle size distribution of cement, DTA as well as experimental conditions are designed. More than 70 cements are investigated on hydration characteristics in this work.According to theoretical calculation, the molar of hydrochloric acid needed to dissolve certain amount of cement clinker is obtained in order to design experiments on cement insoluble residua. In this experiment the results of insoluble residua are equivalent to those of actual admixture addition, and the absolute error is less than 0.6%. Residua results can afford gist to amend cement hydration characteristic at early stage. New concepts such as equivalent hydration heat, equivalent gelatin-pore ratio, equivalent chemically bound water are put forward in this paper according to insoluble residua investigation.By investigation it indicates: Hydration heat evolution of Portland-type cements at very early age show the common trend. The time for first peak of heat evolution is not so discrepant, but the peak values are discrepant very much according to different samples. Insoluble residua contents affect, to certain extent, on the accumulating heat as well as first peak value at early hydration, but less on the time for first peak. Paste conductance is affinity to cement setting and hardening. Curves of those have common variety rule, which are assigned to five stages. Relativity between T_LK corresponding to the...