Strength prediction model for cement mortar made with waste LDPE plastic as fine aggregate

Abstract

Non-biodegradable aggregate prepared from low density polyethylene (LDPE) plastic was used as partial replacement for sand in cement mortar. Various volumetric fractions of 0, 5, 10, 20, 30, 40, 50, and 60% sand were replaced using ground LDPE waste plastic. Mortar mixtures of 1:3 cement to fine aggregate were prepared at various water/cement ratios of 0.45, 0.50, 0.55 and 0.60, then used to cast 50 mm cubes and 40 × 40 × 160 mm prisms. It was found that strength reduces significantly as the proportion of LDPE in mortar increases, however, mixtures containing 50–60% LDPE satisfy the strength criteria for masonry mortars. Based on experimental data, a model was proposed for predicting the compressive strength of mortars containing waste plastics. The model’s validation gave generally accurate predictions for the strengths of mortars made using different types of plastics.