Performance of cement mortar made with recycled high impact polystyrene

This paper investigates the possibility of utilizing recycled high impact polystyrene (HIPS) as a sand substitute in cement mortar, in order to reduce the solid waste disposal problem and thereby environmental pollution and energy consumption. The results show that the compressive strength and splitting tensile strength of mortar are decreased by replacing sand with HIPS, but the decrease in the splitting tensile strength is much smaller. HIPS makes the mortar become more ductile and increases the energy dissipation capacity. HIPS decreases the dry bulk density, dynamic modulus of elasticity, thermal conductivity, and also water vapor permeability, but does not affect the resistance to freeze–thaw cycles. The use of mortar made with various percentages of HIPS offers promise for applications as medium or light weight concrete, mostly due to its improved thermal isolation, while adding value to a post-consumer plastic material that is now generally treated as solid waste.