The effect of dosage of redispersible powders on the properties of fine-grained concrete after repeated freezing-thawing
Abstract
The effect of dosage of redispersible powders on the properties of fine-grained concrete after repeated freezing-thawing
Incoming article date: 12.08.2019The introduction of RPP to 3% by weight of the dry concrete mixture is accompanied by a decrease in the compressive strength of fine-grained concrete aged from 28 days to 37%, and after 75 cycles of freezing and thawing - up to 46%. The decrease in tensile strength in bending at the age of 28 days was 25%, after 75 cycles - up to 23%. The dependence of the initial modulus of elasticity of concrete on the compressive strength remains virtually unchanged after 75 cycles of freezing and thawing. The dependence of the adhesion of MZB to the concrete base with increasing dosage of RPP is ambiguous. The maximum increase in adhesion to the concrete base after 28 days of curing in NU and after 75 cycles of freezing and thawing was 26%. An increase in RPP dosage to 3% leads to a decrease in the initial elastic modulus of MZB to 26% after 28 days of curing in NU and to 32% after 75 cycles of freezing and thawing.
Keywords: dry building mixes, redispersible polymer powders, adhesion to the base, elastic modulus, tensile strength, freezing and thawing cycles