Study of the Effect of Hydrophobic Modifiers on the Properties of Cement Mixtures

Abstract

This article comparatively studies the effect of zinc stearate and polyhydroxysiloxane 136-41 hydrophobic modifiers on the structural and operational properties of cement-sand mixtures. The experiments were conducted on the basis of cement from Ohangaronsement JSC and sand from the Chinoz mine, with a water-cement (Water/Cement) ratio ranging from 0.4 to 0.7. It was found that zinc stearate (1% by weight of cement) did not reduce the compressive strength of cement stone at all test periods, but rather increased it by 13.3–60.7% compared to control samples. According to the water absorption reduction efficiency factor (Pw), zinc stearate reduced capillary absorption by 2.51–3.03 times in the initial period to result twice as high as conventional polyhydrosiloxane. The results obtained prove that the use of zinc stearate is highly effective in ensuring the long-term durability of plaster coatings in the sharply continental climate of Uzbekistan.