Strength evaluation of sustainable concrete incorporating pelletized plastic aggregates: a remedy for growing plastic wastes issue

The polyethylene terephthalate bottles used for cold drinks are disposed of as waste material worldwide, causing environmental pollution. For remedial measures to address this issue, the wasted polyethylene terephthalate bottles were recycled and used as pelletized aggregates in concrete. For performance evaluation, concrete with recycled ethylene terephthalate aggregates, with volume fractions of 5%, 10%, 15%, 20%, 25%, and 30%, was tested and compared with regular concrete. Laboratory tests were conducted to assess—composite and conventional concrete’s fundamental mechanical properties, thermal conductivity, and ductility. The test results revealed that with the increase in recycled ethylene terephthalate aggregates, the workability of the concrete significantly decreases along with other associated mechanical properties. Considering the limited compressive strength, Polyethylene Terephthalate (PET) based concrete can be used in concrete elements, which requires the lower compressive strength value specified by the ACI code. Due to the lower unit weight and thermal conductivity value, this composite concrete can be used for up to 30% in the construction industry, subject to the lower value of desired strength.