Performance-based experimental study into quality zones of lightweight concrete using pumice aggregates

Abstract

The quality and performance of concrete depends on the material used. Lightweight concrete is usually formed from aggregates with lightweight specific gravity, such as pumice. This study aims to identify the zone of quality and performance of concrete when partially replacing coarse aggregate (NA) with pumice coarse aggregate (PA). The performance parameters studied include unit weight, compressive strength, elastic modulus, tensile strength, and rupture modulus. Geochemical analysis and porosity of aggregate were carried out using SEM and X-RD. The percentage variation of pumice aggregate is 0 %PA, 25 %PA, 50 %PA, 75 %PA, and 100 %PA. Quality zones based on observations of the behaviour and mechanical properties of concrete are determined. The results show that concrete using PA consists of two quality zones, namely the brittle zone for concrete with PA above 50 % and the ductile zone for concrete with PA below 50%. Formulas to calculate the elastic modulus and the rupture modulus are proposed. Utilisation of pumice as lightweight concrete aggregate to get better lightweight concrete performance must be selective.