Mechanical and physical properties and morphology of concrete containing plastic waste as aggregate

The valorisation of plastic wastes has become a major environmental challenge. Their re-use as aggregates in the manufacture of new construction materials may contribute to eliminate these wastes and help to protect the environment, and to achieve sustainable development as well. The present work is part of an ambitious, sustainable development program. In the present experimental study we evaluated and compared the impact of substituting both fine and coarse aggregates with three plastic wastes. The wastes were; polypropylene PP, high-density polyethylene HDPE, and polyvinylchloride PVC based. Different amounts (25, 50 and 75%) of natural aggregates were substituted with the same volume of plastic aggregates. In addition to morphology, thermo-mechanical and acoustic properties, their environmental impact were evaluated. The results show, that plastic waste has a positive effect by decreasing the density. Moreover, the concrete with 75% of PE aggregate presents the lowest dynamic elastic modulus; which correspond more ductile composite. Incorporating 75% of PVC aggregates into concrete caused the thermal conductivity to decrease until 0.61 W/m·k. The use of plastic wastes in concrete allows developing a composite material with interesting acoustic insulation characteristics. Recycling waste plastics, to be used in the formulation of concrete, promising solution to reduce the impact of plastics on the environment and consequently fight pollution and global warming.