A Study on Use of Polymeric Waste Materials in Concrete for Road Pavements

Concrete, while strong in compression, is weak in tension and prone to brittleness, leading to early crack formation and limiting its use in pavements due to the lack of ductility and susceptibility to fracture and failure. These drawbacks can be addressed by incorporating fibers as reinforcement in the concrete mix. Waste materials like polyethylene and tires, which contribute to environmental pollution, can be recycled and used as fiber reinforcement in concrete, enhancing its mechanical properties. Polyethylene, a synthetic hydrocarbon polymer, is known to improve ductility, strength, and shrinkage characteristics in concrete. This study investigates the effects of adding polyethylene and tire fibers on the properties of concrete. Polyethylene and tire fibers, cut to 30mm x 6mm, were used at 1.5% each by volume. The concrete mixes were designed for M30, M35, and M40 grades following IRC 44:2017 guidelines. Strength properties were evaluated through a series of tests, including a 4-point bending test and double shear test for determining flexure and shear strength. The results showed an 18% increase in 28-day compressive strength, a 39% increase in flexural strength, and a 32% increase in shear strength. Additionally, there was a 22% reduction in deflection in the 4-point bending test and a 36% reduction in the double shear test. Theoretical deflection values were analyzed using energy methods and aligned with practical values within permissible limits. In conclusion, recycled polyethylene and tire fibers can be effectively utilized in reinforced cement concrete, offering significant improvements in mechanical performance.