Influence of Calcium Stearate Ca(C₁₈H₃₅O₂)₂ on the Properties of Fine-Grained Concrete

Abstract

The article presents experimental data obtained during the use of powdered calcium stearate and its suspension as bulk water repellents for fine-grained concrete. The use of powdered calcium stearate in an amount of 0.5% of the mass of cement led to an increase in air intake by 1.7 times, mobility by 8.5%, and a decrease in density by 2.5% compared to similar indicators of a concrete mixture without a water repellent. Powdered calcium stearate had no significant effect on compressive strength and flexural strength. With the introduction of CS in the form of a suspension and a powder in an amount of 0.5%, the capillary water absorption was reduced by 3 times, the water absorption by weight after the first day was 19% less than that of the samples without the additive. During the first day, water absorption for samples with a suspension of CS in an amount of 0.5% was 8.8%, for samples with CS powder - 7.6%. The highest water absorption is typical for samples without a hydrophobization and was equal to 9.3%, the lowest for samples with an CS suspension in the amount of 1.5% –4.4%. The introduction of a suspension of calcium stearate in an amount of 0.5% by weight of cement led to an increase in air entrainment by 2.1 times, a decrease in density by 4%, and a decrease in mobility by 5% compared to the samples without additive.