Concrete and recycled plastic curbs for shaping planters: Towards a more sustainable product

Abstract

The primary objective of this research study is to reuse waste concrete discarded from academic teachings and to recycle PET (Polyethylene Terephthalate) plastics to make garden planters. An innovative design of concrete curbs is proposed with weights ranging between 15 and 25 kg. Concrete mixtures with different PET additions (0, 0.5, and 1.0%) are characterized experimentally and an analysis of sustainability solution aspects is performed. The results show that discarded concrete can achieve the minimum resistance to compression of 15 MPa for all the mixtures studied. Using this solution, it is estimated that six tons of concrete are reused per year, up to 40 PET bottles per concrete curb are recycled, 40.66 kg of CO2 emissions are avoided annually, and 1,345.40 kWh of energy consumption are saved. It is concluded that the concrete curb mixture developed from recycled materials to make garden planters is an excellent alternative to reduce waste concrete and to recycle PET plastics.