Concrete with rejected recyclable plastic waste at high temperatures

The physical, chemical and mechanical properties of concrete incorporating rejected recyclable plastic waste (RRPW), the potential for the mitigation of heat-induced concrete spalling and the effects of high temperature on the residual properties of concrete were investigated. Concrete compressive and tensile strengths, Young’s modulus, crack width, mass loss, water absorption by capillarity, chemical composition and evidence of heat-induced concrete spalling were monitored in concrete samples made with RRPW particles and compared with those of concrete samples made with commercial polypropylene (PP) fibres, after exposure to 200°C, 400°C and 600°C for 2 h. The use of 0·125% by volume of PP fibres and plastic waste particles was found to improve the heat-induced concrete spalling performance, due to the release of internal pressure after melting by different mechanisms. The positive effects on concrete properties show the technical potential of incorporating RRPW particles in construction materials