Flexural response of fiber reinforced concrete beams with waste tires rubber and recycled aggregate

The increasing amount of waste tires and construction wastes mounting up on the landfills create a huge concern to environmental stability. Researchers and policymakers are searching for ways to reduce and reuse these waste materials to promote a sustainable construction practice. Thus, incorporating crumb rubber (CR) derived from the waste tire and recycled coarse aggregate (RCA) in concrete production pertains to a sustainable future of the construction industry. This paper investigates the combined influence of RCA, CR, and polypropylene (PP) fiber on the physical and mechanical properties of Fiber Reinforced Rubberized Recycled Concrete (FR3C). Furthermore, the flexural response of reinforced concrete (RC) FR3C beams is investigated. A series of fourteen RC beam specimens measuring 150 mm x 200 mm x 1500 mm (w x d x L) are prepared and tested. Several combinations are designed where the variables are CR content (5% and 10%) and steel ratio (0.59% and 1.60%) with contents of RCA and fiber fixed at 30% and 0.5%, respectively. The results of the experimental study suggest an improvement in the concrete short-term and long-term mechanical properties following the introduction of CR and PP fiber. Concrete beams with 30% RCA, 5% CR and 0.5% PP fiber showed improved flexural capacity, ductility, and toughness. Additionally, analysis demonstrates that the existing codes and design guidelines are inadequate for quantifying the flexural capacity of FR3C beams with different reinforcement ratios. Overall, this research demonstrates a new pathway towards the cleaner production of sustainable concrete. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

This research investigates the impact of waste materials on recycled concrete, improving its mechanical properties through the introduction of crumb rubber and polypropylene fiber. Concrete beams with the mixture of materials exhibit enhanced performance, while existing design guidelines are inadequate in assessing their load-bearing capacity.