Valorisation of waste expanded polystyrene in concrete using a novel recycling technique

Abstract

This study examines the engineering properties of lightweight aggregate concretes (LWACs) incorporating a novel Expanded Polystyrene (EPS)-based lightweight aggregated called Stabilised Polystyrene (SPS). The SPS aggregate was produced by 80% waste EPS, 10% clay and 10% cement. The influence of the increasing incorporation of SPS on the workability, density, compressive strength, flexural strength, ultrasonic pulse velocity, drying shrinkage, expansion and water absorption (WA) of the different concretes has been investigated. The results showed that the use of SPS enabled to reduce the density of concrete by 8–52% compared to that of the control concrete. The reduction in density was due to the increase in total porosity in the lightweight concretes (LWCs), which also induced higher WA, drying shrinkage and expansion. The 28-day compressive strength of the LWAC was in the range of 4.6–16.4 MPa; thus, the concrete mixture with the higher performances almost satisfied the mechanical and density criteria of structural LWC. These results show that the utilisation of SPS for the manufacture of LWACs is possible.