Effect of combination of waste glass powder and plastic aggregate on structural behavior of reinforced concrete beams

Abstract

This work was carried out to investigate the structural behavior of reinforced concrete beams incorporating 0 % and 15 % waste glass powder combined with (0, 10, and 20 %) plastic aggregate. Fifteen beams were tested with (150 mm) depth, (150 mm) wide, and (900 mm) length. These beams were strengthened by different longitudinal steel ratios of 0.0056 (2Ø8), 0.0125 (2Ø12), and 0.0222 (2Ø16) with two ratios of shear reinforcement (stirrup at every 60 mm and 150 mm). To understand the structural behavior clearly, the results were displayed based on four parameters: the effects of waste glass powder, crushed waste plastic, longitudinal, and transverse reinforcement. Empirical outcomes showed an improvement in the structural behavior of beams incorporating these wastes. An enhancement in the maximum load value was observed by increasing the longitudinal reinforcement, but the beams exhibited less deflection and ductility. The higher ultimate load was 158 kN, recorded for the beam that was reinforced longitudinally by 2Ø16 mm and transversely by stirrups Ø6 mm at a space of 60 mm between them and contained 15 % glass powder with 10 % plastic aggregate. It is found that the presence of glass powder and plastic aggregate can be more beneficial considering the response of deflection, ductility, and total energy. Regarding the influence of crashed waste plastic, the increase in the proportion of added plastic caused a rise in the maximum deflection, ductility index, and total absorbed energy for 20 % plastic aggregate by up to 47.26 %, 13.84 %, 49.04 %, respectively compared to the control beam. In contrast, these characteristics values were decreased up to 80.89 %, 82.21 %, and 54.57 %, respectively with increasing the tensile steel ratio to 0.0222 (2Ø16) compared to the beam that was reinforced by 2Ø8 mm with the same content of glass and plastic.