Preliminary Study on Using LDPE, LLDPE and PP Waste as Concrete Aggregates

Over the years, plastic production has increased in direct proportion to the amount of plastic waste generated globally. Single-use plastics such as low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE) and polypropylene (PP) have increased significantly. Therefore, they can be used as aggregates in the production of concrete to reduce the generation of plastic waste in the environment. LDPE, LLDPE and PP were the plastic types used, with 25% and 50% of plastic aggregate replacing sand. The tests included Fourier-transform infrared spectroscopy (FTIR) analysis of the plastic granulate, density, and compression tests of the concrete specimens. The type of granulate used follows the type of plastic tested from the results of the FTIR characterization. It was found that the compressive strength of concrete containing 25% of plastic aggregates was higher than that of concrete containing 50% of plastic aggregates. The compressive strength of the LLDPE concrete specimens is 31.4 MPa, whereas the compressive strength of the LDPE concrete specimens is only 26.3 MPa and that of the PP concrete specimens is 30.4 MPa. Further research will be carried out to determine the optimum strength of concrete with plastic aggregates.