Effect of Active Admixture and Air Entraining Agent on Frost Resistance of Volcanic Scoria Thermal Insulation Plastering Mortar

Abstract

The effects of fly ash, slag powder, diatomite and air entraining agent on the mechanical properties and freeze-thaw resistance of volcanic scoria thermal insulation plastering mortar were studied by orthogonal test. The test results showed that the thermal insulation plastering mortar achieves the best performance when the replacement rate of fly ash was 20%, the substitution rate of slag micropowder and diatomite is 10%, and the amount of air entraining agent is 0.1%. Compared with the ordinary thermal insulation plastering mortar, the 28d compressive strength is increased by 17.8%, the strength loss rate was reduced by 34.5% and the quality loss rate was reduced by 43.3%. Observing the microstructure of the thermal insulation plastering mortar by SEM, active admixture is beneficial to improving the structure of the hydration product and improving the compactness of the thermal insulation mortar.