PHYSICAL AND MORPHOLOGICAL INVESTIGATION OF THE UTILIZATION OF EXPANDED PERLITE AS FINE AGGREGATE FOR TYPE M STRUCTURAL LIGHTWEIGHT MORTAR

Abstract

The study examined the influence of expanded perlite aggregates (EPA) on mortar properties and whether EPA could replace sand to produce mortar that meets the compressive strength requirement of ASTM Type M mortar. The study involved fabricating mortars wherein sand was substituted by volumes of 20%, 40%, 60%, 80%, and 100% with three types of EPA (EPA A, EPA B, and EPA Coarse). Results showed that EPA-mortars can meet the ASTM compressive strength requirement of 17.2 MPa. The sample attained its greatest compressive strength of 29.19 MPa, which is nearly equal to the control sample strength of 29.42 MPa, upon replacing sand with 60% by volume of EPA A. In comparison to the control mortar density of 2055 kg/m3, Type M EPA mortar density can drop as low as 1422 kg/m3, which is a 30.8% decrease. Additionally, it was observed that EPA microstructure played a role in the resulting mortar compressive strength. Mortars with the highly absorbent EPA Coarse were found to have less compressive strength than mortars that used EPA A, which has a lower capacity for absorption and more intact microstructure.