Effect of Partial Replacement of Coarse Aggregate with PVC Plastic Fibers on Some Properties of Concrete

Abstract

Polymers are considered fundamental materials in modern industries due to their lightweight nature, flexibility, and high chemical resistance. Among the most prominent polymers is polyvinyl chloride (PVC), which is characterized by favorable mechanical and thermal properties as well as low cost. This study aims to evaluate the effect of partially replacing coarse aggregate in concrete mixtures with PVC fibers at substitution levels of 5% and 10% by weight of aggregate. A series of concrete mixtures were prepared with a design compressive strength of 25 N/mm². In these mixtures, part of the coarse aggregate was replaced with PVC fibers in the form of thin, fluffy wires at weight ratios of 5% and 10%. The results were compared with a reference mixture. After 28 days of curing, the compressive strength of the reference concrete was 36.4 N/mm². When 5% of the coarse aggregate was replaced with PVC fibers, the compressive strength was reduced to 28.93 N/mm². Interestingly, increasing the replacement ratio to 10% resulted in a higher strength of 31.7 N/mm². Although the compressive strength decreased compared to the reference mixture, it remained above the required design strength of 25 N/mm².  A slight reduction in specimen weight was also observed with increasing replacement ratios. The reference specimen weighed 8.1 kg, while the weight decreased to 7.81 kg at 5% replacement and further to 7.76 kg at 10% replacement. These findings indicate that substituting PVC fibers for part of the coarse aggregate contributes to weight reduction, thereby enhancing the potential for use in structural applications that demand high mechanical performance with lower density. The significance of this research lies in highlighting the feasibility of using the studied fibrous form of PVC as an innovative additive to improve the properties of conventional concrete and to open new horizons in construction material technology, particularly in achieving sustainability. The study recommends conducting further investigations to explore additional replacement ratios and different treatment techniques to further enhance performance.