Effect of Waste Expanded Polypropylene-Based Aggregate on Mechanical and Thermal Properties of Lightweight Concrete

Resource efficiency and building energy consumption is in recent years an open question for construction industry. Recycled plastic aggregate can be used as an alternative aggregate to produce lightweight concrete with low environmental impact of both concrete and waste plastic and moreover, the obtained lightweight concrete is characterized by improved thermal insulation properties. In the present study, waste expanded polypropylene (EPP) aggregate is used for partial replacement of natural aggregate to produce lightweight cement-based composites containing synthetic coagulated amorphous SiO2 as supplementary cementitious material. For the applied EPP, basic physical properties were measured and specific attention was paid to thermal transport and storage properties that were studied in dependence on compacting time. The effect of EPP content on the mechanical characteristics and on the thermal properties of developed material was investigated for 28 and 90 days water cured samples. Composite with incorporated EPP aggregates exhibits enhanced thermal insulation properties with sufficient mechanical resistance and can be considered as promising material for building subsoil or floor structures.