The Influence of Diatomite on the Strength and Microstructure of Portland Cement

To study the influence of the types and mixing amount of diatomite on the Portland cement, we prepared the cement specimen doped with the calcined first-grade, first-grade and second-grade diatomite, tested the 3d, 7d, 14d compressive strength, and studied and discussed phase, structure and morphology of diatomite in the binary system by the method of XRD, SEM. Experimental results show that with the addition of diatomite, the strength of cement paste increase; the optimal contents of calcined first-grade, first-grade and second-grade diatomite in Portland cement are 5%, Compared to the blank group, the strength of specimen can be increased by 54.6%, 15.4% and 10.2%, respectively; At the same time, the 7d microscopic hydration of different diatomite particles were analyzed through the experiment, and the shell of calcined diatomite particles were better hydrated than that of first-grade and second-grade diatomite particles. The results indicate that the diatomite can improve the strength of cement paste, the hydration of different diatomite particles can influence the growth of cement paste strength.