Investigation of physical and mechanical properties of mortars produced by polymer coated perlite aggregate

Abstract

With its low unit weight, expanded perlite (EP) offers significant advantages in heat and sound insulation in the construction sector. However, due to its high-water absorption capacity, EP affects the physical and mechanical properties of concrete negatively. Therefore, it is aimed to reduce water absorption by coating the EP with polymer and thus to improve its mechanical and physical properties. In this study, mortar production was carried out by replacing coated and uncoated EP with CEN reference sand at 0%, 20%, 40%, 60%, and 80% respectively. The effective water/cement ratio of all produced mortar samples was determined to be 0.6. For coated and uncoated EP aggregate mortar series, unit weight, compressive strength, bending tensile strength, water absorption, ultrasonic pulse velocity (UPV), and thermal conductivity coefficient were determined. The results showed that the unit weight of the mortar samples decreased as the amount of EP increased, but their physical and mechanical properties also changed. Mortar samples with better thermal insulation properties were obtained with decreasing thermal conductivity values. The polymer coating of EP improved physical and mechanical properties. Especially in the 80% substituted EP series, the thermal conductivity decreased from 1.20 to a coefficient of 0.91 W/mK. © 2021