Experimental and numerical assessment of recycled plastic fibers on shear strength and behavior of reinforced concrete beams with basalt FRP bars

Abstract

In response to the growing demand for alternatives to traditional stirrups in construction, discrete fibers have emerged as a promising solution, offering potential time savings during the building process. Among these, the use of recycled plastic fibers has garnered significant attention, addressing both environmental sustainability and material efficiency challenges in the construction industry. This research focuses on incorporating recycled plastic as discrete fibers within concrete beams reinforced with basalt fiber-reinforced polymer (BFRP) bars, with the dual objectives of reducing environmental impact and enhancing construction efficiency. This research investigates the shear behavior and strength of concrete beams reinforced with BFRP bars through both experimental and numerical methods. Three types of discrete fibers (straps, water bottles, and ropes) were examined for their influence on beam performance. The study focuses on two key parameters: the aspect ratio of the fibers and the different materials from which they are made. Seven concrete beams were tested experimentally to assess these effects, and the experimental findings were further validated using finite element analysis FEM by using ABAQUS. The experimental results indicated that recycled plastic fibers did not significantly enhance the shear strength of FRC beams, with the exception of the BFRP-reinforced beam containing 20 mm short water bottle fibers, which showed a 13.97 % improvement in shear strength compared to the control beam. Furthermore, the analytical results aligned well with the experimental findings in terms of failure load, cracking behavior, and deformation behavior, demonstrating strong consistency between the two approaches.