Mechanical properties of EPS lightweight concrete

The aim of this study was to investigate the effects of expanded polystyrene aggregate size, matrix strength and polypropylene fibre addition on the strength of lightweight concrete. Three types of expanded polystyrene beads with 1.0, 2.5 and 6.3 mm diameter were added to a high-strength matrix to produce lightweight concrete. Fine silica fume and polypropylene fibres were used to improve material properties. Lightweight expanded polystyrene concretes with different matrix strengths were investigated for compressive and splitting tensile strength. The expanded polystyrene concrete with small expanded polystyrene beads showed higher compressive strengths and the increase was more pronounced in low-density concrete than high-density concrete. The matrix strength was also observed to affect the particle size effect of expanded polystyrene beads on the compressive strength of concrete. The increase in compressive strength with the decrease of expanded polystyrene bead size was more pronounced in the low-strength matrix. In addition, polypropylene fibres significantly improved the strength of expanded polystyrene concrete, with the 28-day compressive and splitting tensile strengths of expanded polystyrene concrete being up to 43 and 44% higher than those of reference concrete.