Reliabilitybased Study on Minimum Reinforcement Ratio of Recycled Aggregate Concrete Beams

Abstract:

In order to investigate the influence of recycled aggregate concrete (RAC) strength variation on the minimum reinforcement and stirrup ratios of RAC beams, this paper analyzed and compared the ratios of RAC and natural aggregate concrete (NAC) beams subjected to bending moment and shear force with the same target reliability index. The results indicate that the RAC strength variation has limited influence on the flexural capacity variation with the existence of reinforcements. As a result, the minimum reinforcement ratio almost does not increase when the beams are subjected to moment. As for the beams subjected to shear force, when the coefficient of variation of RAC tensile strength is 0.2, the minimum stirrup ratio of RAC beam is 0.17% and increases about 32.0% compared with NAC (grade C30) beam. The reliability indexes of RAC and NAC beams can be equal by increasing the reinforcement and stirrup ratios reasonably.