Structural Performance of Reinforced Concrete Affected by Plastic Materials

This novel study provides new experimental evidence and a detailed comparative analysis of how various types of plastic materials influence concrete performance. Six widely used plastic materials were examined for their impact on the flexural strength of reinforced concrete (RC) beams, as well as the compressive strength, elastic modulus, and durability of concrete specimens. In the experimental program, 10% of the natural fine aggregate was replaced with particles of polyethylene terephthalate (PET), high-density polyethylene (HDPE), polyvinyl chloride (PVC), low-density polyethylene (LDPE), polypropylene (PP), and polystyrene (PS). A simplified life cycle assessment (LCA) model was included to compare the greenhouse gas emissions (measured as CO₂-e) from managing plastic waste. The new experimental data indicate that, overall, incorporation of plastic waste materials into concrete has modest adverse effects, suggesting the viability of the resulting product as a sustainable material alternative. Flexural tests on RC beams showed that the addition of plastic particles has no adverse effects on flexural behavior under the specific test conditions. Furthermore, durability assessments using ultrasonic pulse velocity and electrical resistivity tests confirmed that plastic-modified concrete performs comparably to conventional mixes. LCA revealed that, with strategic improvements in recycling technology and logistics, using plastic waste in concrete can become an environmentally friendly option, helping to reduce the carbon footprint.