INFLUENCE OF LIGHTWEIGHT AGGREGATE CONCRETE ON SHEAR BEHAVIOR OF BEAMS WITHOUT SHEAR REINFORCEMENT: AN EXPERIMENTAL STUDY

In order to investigate the influence of aggregate types on shear behavior of reinforced concrete beams without stirrups, 16 simply supported beams, which consist of 8 beams with normal concrete and 8 beams with lightweight aggregate concrete, were tested to shear failure under point load. The main variables in the test are shear span to depth ratio and longitudinal reinforcement ratio. The shear failure pattern, the propagation and development of diagonal cracks, the relative displacements of the critical shear cracks and the shear strength of the lightweight aggregate and normal concrete beams were analyzed and compared. The test ultimate shear strength were compared with the predictions of Chinese Specification for Design of Lightweight Aggregate Concrete Structures JGJ 12-2006 and Code for Design of Concrete Structures GB 50010-2010. The results shows that the predictions of JGJ12-2006 were not conservative enough for the shear strength of lightweight aggregate concrete beams, and may lead to an unsafe design.