THE EFFECT OF PET AND LDPE PLASTIC WASTES ON THE COMPRESSIVE STRENGTH OF PAVING BLOCKS

Abstract

Plastic is one of the most common environmental problems in the world. One way to reduce plastic waste is by reusing it to produce other materials such as partial replacement of sand in paving blocks mixture. Paving blocks (concrete brick) are a building material made of a mixture of water, aggregate, and portland cement. An experimental study was carried out to investigate the effect of low-density polyethylene (LDPE) plastic and polyethylene terephthalate (PET) plastic as a substitute for fine aggregates on the compressive strength of paving blocks. In this study, paving blocks are planned to be off plan C quality with a minimum compressive strength of 12.5 MPa, which is usually used as a pedestrian facility. Plastic wastes (LDPE and PET) are used as a partial replacement for fine aggregates, with 0%, 5%, 10%, and 15% volume variations of the fine aggregate. In addition, fly ash was added to LDPE mixtures (LDPEF) with the fly ash content used is 15% by replacing the weight of cement. The compressive strength test was carried out on cylinder specimens of 150 mm diameter and 300 mm length. The results show that the use of LDPE and PET plastic wastes as a partial replacement of fine aggregate decreased the compressive strength by 35.26%; 37.69%; 40.68% for LDPE, 34.15%; 52.22%; 56.53% for PET, and 23.14%; 18.01%; 24.65% for LDPEF, respectively. However, the compressive strength result of the tested paving blocks predominantly exceeds the minimum requirement for compressive strength of paving blocks quality C, 12.5 MPa.