Strength behavior of reinforced concrete beam using re-cycle of PET wastes as synthetic fibers

The purpose of this paper is to evaluate the mechanical properties of normal concrete (NC) containing polyethylene terephthalate waste fibers (PETWF). In addition to check the influence the waste has on the behavior of reinforced concrete beams, five mixtures of NC with 0.41 of w/c ratio were tested. The mixtures contain four NC mixtures with various percentages of PETWF in different shapes and lengths. After that, the behavior of four 150 × 200 × 1400 mm simply supported concrete beams, including different percentages of the wastes within the concrete mixture was investigated via the influence of the wastes on the strengths and serviceability of concrete beams. Suitable tests were carried out to assess mechanical characteristics of mixtures that contain the plastic waste and compared with that of the control mixture. The tests variables of reinforced concrete beams included load-deflection behavior, cracking investigation, ductility indices, and stiffness. Testing of reinforced concrete beams showed a little decrease in the ultimate failure load of the specimens and secant stiffness. Nevertheless, there was prominent improvement in ductility behavior for all beams, especially in the hybrid beam, and also increase in the initial stiffness.