In this work, polyethylene terephthalate waste products were recycled in the form of a molten polymer then mixed with silica sand particles in different weight ratios (5–40% of sand particles with 0.062–0.35mm in diameter) in the form of particulate composites. Compression and three point bending tests were carried out on the composites at temperatures of −20, 25, 40, 60 and 80°C. In addition, to estimate the pseudo-cohesive strength between fine particles forming the structure of composites studied, the corresponding compression tests were numerically modeled. The obtained results show that the composites studied have the highest mechanical strength and pseudo-cohesive strength at the temperature of 25°C. Also, by increasing the weight percent of particles up to 10%, the strength of composites increases and beyond that (i.e. 20% and 40% sand) it decreases.