Mechanical properties of concrete using different types of recycled plastic as an aggregate replacement

Abstract

This study examined the quality of concrete using polyethylene terephthalate (PET) and polypropylene pipe (PEP) as aggregate replacements. In concrete mixtures, PET and PEP replaced up to 15% of the aggregates. Several laboratory tests were conducted to assess the effects of these replacements on the quality of concrete mixtures. Workability, unit weight, modulus of elasticity, compressive strength, indirect tensile strength (splitting), and flexural strength were tested. This study reveals that the two types of plastic waste materials can be successfully used as partial replacements for sand or coarse aggregates in concrete mixtures. PEP reduces workability, whereas PET enhances this material property. A lighter concrete density, up to 10% less than that of the control mixture, was obtained. The use of recycled plastic reduced the compressive strength, tensile strength, and flexural strength by up to 31%, 22%, and 60%, compared with normal concrete, respectively. A finite element model was used to simulate the flexural beam test using the modulus of elasticity obtained from the experimental tests to examine the behavior of normal concrete, PET, and PEP concrete. Dedicated results were obtained using FEs for the failure mode and flexural capacity.