Utilization of plastic waste as replacement of natural aggregates in sustainable concrete: effects on mechanical and durability properties

The study presents the mechanical and durability properties of concrete made up of recycled-waste-polyethylene (PE) and waste-polyethylene-terephthalate (PET)-based aggregate as replacement of natural fine and coarse aggregate, respectively. For this purpose, compressive strength, sorptivity, water permeability, aggressive exposure in acid, base, marine and wastewater, impact resistance, abrasion loss including surface and Cantabro, gas permeability, rapid chloride penetration test (RCPT), elevated temperature and leachability test of microplastic were performed. The experimental works were performed for different volumetric replacement (0–40%) of natural fine and coarse aggregates by PE and PET made aggregate respectively for different curing periods. The experimental results revealed that the sorptivity of PE-based concrete was lowest. Water permeability coefficient signified that with the increase of percentage of PET water permeability increased. In case of aggressive exposure test, the percentage of residual mass and residual strength for all replacement was decreased with the increase in exposure period. Further, impact resistance test result signified that energy absorption increased with the increase of PE and PET percentages. Cantabro and surface abrasion weight loss showed similar trend. Carbonation depth was increased with increasing percentages of PE and PET signified strength decreased with increase of percentages of PE and PET when subjected in CO(2). RCPT test results demonstrated that with increase of PE and PET percentages chloride ion penetrability was reducing. It is observed that below 100 °C temperature, compressive strength of all mix proportions was not affected with elevated temperature. Moreover, the PET-based concrete showed no presence of microplastic in case of leachability test.