Changing the properties of building mortars with redispersible polymer powder after cyclic heating-cooling
Abstract
Changing the properties of building mortars with redispersible polymer powder after cyclic heating-cooling
Incoming article date: 07.01.2023The effect of redispersible polymer powders on the change in the properties of building mortars after 60 cycles of heating to 60 ° C and cooling is investigated. An increase in the compressive strength from 11 to 27% was revealed at a dosage of RPP from 1 to 3%, and the introduction of an air-entrapping additive into the composition does not contribute to an increase in the compressive strength. A significant increase in the ratio of the tensile strength "flexural tension" has been established/compression", while the tensile strength of building mortars during bending practically does not change with an increase in the dosage of RPP, and the increase in tensile strength during bending occurs to a lesser extent than that of building mortars without RPP, and the presence of an air-entrapping additive contributes to an increase in the tensile strength during bending. A decrease in the initial modulus of elasticity was found almost independently of the dosage of the RPP to values of 0.82 – 0.84, and in the presence of an air-entrapping additive to 0.9 relative to normal hardening conditions. A decrease in the adhesion strength to the concrete base to values of 0.59 – 0.75 relative to normal hardening conditions was revealed. The presence of an air-entrapping additive leads to an increase in the adhesion strength after cyclic heating-cooling by more than 4 times.
Keywords: redispersible polymer powder, adhesion strength, modulus of elasticity, compressive and bending strength, cyclic heating-cooling