Influence Of Longitudinal Reinforcement Ratio On Shear Behavior Of Simply Supported Beams With Web Reinforcement When Shear-Span Ratio Is 1.5

Previous researches carried out by numerous scholars have suggested that the longitudinal steel ratio has influence on the shear strength resistance of the reinforced concrete members. A majority of previous studies on the effect of longitudinal reinforcement ratio on shear behavior of reinforced concrete members concerned about beams without web reinforcements and ultimate capacity, few gave detailed recording of development of cracking and failure process of RC beams with web reinforcements.This paper is a part of series of experimental study. Four simply supported beams with web reinforcements and different amount of longitudinal reinforcement were tested under static two-point symmetrical concentrated loading, with the shear-span ratio being kept around 1.5. The overall development process of cracking under shear and the effect of longitudinal reinforcement ratio on cracking, failure modes, strain distribution of reinforcements and ultimate capacity of RC beams with web reinforcements were investigated. The results of this experiment and a previous one done by Wang Wei were combined and compared with shearing resistance strength value predicted by The Chinese Code GB50010-2002 and the shearing strength value predicted by Response2000.At first, development of various cracks was carefully recorded and strains on both the longitudinal reinforcements and the stirrups were measured in detail, together with deflections of the beam. Furthermore, correlation between the measured strain profiles of the reinforcement and the observed cracking development of each specimen was pursued. Principal factors contributing to the cracking pattern and failure mode were figured out as a result Secondly, comparison of the tested results unveiled effect of various longitudinal reinforcement ratios on development of cracking, final failure mode, and ultimate capacity. Primary conclusions were thus drawn. Performance of beams under moment and shear may be different from that under pure moment or pure shear. Consequently, the shear-bending interaction relationships of specimens were investigated in this paper.The experiments showed that different amount of longitudinal reinforcement had a significant impact on formation of different cracks. In the specimen with the web reinforcement, the flexure crack first appears at the mid span in the pure bending segment. Along with load growth, flexure-shear inclined crack or the web shear...