EFFECTS of DIFFERENT TYPES OF RECYCLED POLYMER AGGREGATES on MECHANICAL PROPERTIES of CONCRETE

Plastic waste control has always been a major concern in many countries. The amount of these substances increases every year due to continued public consumption. Given the high cost of plastic recycling in developing countries, returning these materials to the industry for the production of building materials can be a viable solution to protect the environment. Since concrete is one of the most widely used composite materials in the building industry, it, therefore, provides a suitable base for the utilization of plastic waste. In this research, different plastic granules are replaced with a certain amount of fine natural aggregates, and the physical and mechanical properties of the concrete made from these materials are evaluated by necessary tests. The target plastics are Polypropylene, High Impact Polystyrene, and Polyethylene terephthalate. The size and aggregation of the mentioned fine plastic particles are similar, replacing the sand with 15% and 30% by weight. The results show that the mechanical properties of the concrete decrease as the amount of substituted plastic aggregates increases. However, among the concrete made with plastic aggregates, the one which contains High Impact Polystyrene, has the best performance. In addition, the workability of the concrete was improved by increasing the amount of plastic aggregate present in the concrete. However, in the concrete containing Polyethylene terephthalate, this index declined. Also, among the physical and mechanical properties of concrete, flexural strength and ultrasonic pulse velocity of concrete were the most varied, but the compressive and tensile strength and workability have undergone fewer changes.