Investigation of polymer injection molding using calcareous waste concrete powder and polyethylene

This study fabricated composite materials using waste concrete powder (WCP) and linear low-density polyethylene via injection molding to improve the resource value of polymer composites of waste concrete. The flexural strength and modulus of the composite material improved with increasing WCP content and did not decrease even at a WCP content of 60 wt%. Moreover, the effect of the WCP particle size on the mechanical properties of the composite was low for composites with a WCP content of 20 wt%. To investigate the effect of the WCP particle size on the mechanical properties of the composite material in detail, the von Mises stress distribution of the composite material with a WCP content of 20 wt% was analyzed using finite element method (FEM). The von Mises stress distributions of the composite materials were almost identical across all WCP particle sizes. The results from the experiment and FEM analysis suggested that the interfacial adhesion between the WCP and LLDPE is in good condition. Therefore, it can be concluded that injection molding using WCP and LLDPE is feasible and WCP shows promise as a reinforcement particle.Highlights Fabrication of plastic composite material using the WCP by injection molding. The flexural strength and modulus increased by adding the WCP. The effect of the WCP particle size on the mechanical properties was low. The Mises stress were almost identical at each WCP particle size. The WCP is promising reinforcement of flexural strength and modulus.