EXPERIMENTAL RESEARCH ON MECHANICAL BEHAVIOR OF LIGHTWEIGHT AGGREGATE CONCRETE BEAMS

摘要

Based on the experiment of 5 beam specimens (including 2 lightweight aggregate concrete beams, 1 fiber lightweight aggregate concrete beam and 2 normal-weight concrete beams), the mechanical properties of lightweight aggregate concrete beam ( including the failure pattern, bearing capacity, the changing regularity for deflections and the development of cracks) are analyzed and studied. Comparisons are made among the lightweight aggregate concrete specimens, fiber lightweight aggregate concrete specimen and normal-weight concrete specimens on the respects mentioned above. A comparison is made between the experimental results of deflection under service load and the allowable values of Specification JGJ12-2006. The test results of crack width are also compared with computed values based on current Specification. The analysis results indicate that the experimental deflection results can meet the requirement of the allowable value. It is safe to estimate the lightweight aggregate concrete beam's crack width using the formula of Specification JGJ 12-2006. But the formula should be revised when it is used on lightweight aggregate concrete beams after mixing polypropylene fiber.