STUDYING THE BEHAVIOUR OF LIGHTWEIGHT DEEP BEAMS WITH OPENINGS

In this study experimental tests were conducted to investigate the behavior of reinforced concrete deep beam with openings using lightweight concrete. The experimental program involved of testing thirteen simply supported deep beam specimens which tested under static two-point loads. Light expanding clay aggregate (LECA) was used to produce lightweight concrete. Test variables were the shape and size of openings, reinforcement around the openings, position of the openings and shear span to depth ratio. It was found that the behavior of deep beams which made of lightweight concrete is similar to that made of normal concrete. It was concluded that the ultimate load and the measured maximum deflection in beams that have circular openings are larger compared to that have rectangular openings. At the same time, the ultimate load decreased and the measured values of maximum deflection increased with increasing the size of the openings in deep beams. Also, it was found that providing steel reinforcement around the openings caused an increasing in the load capacity of the tested beams. Decreasing the shear span ratio from 0.5 to 0.4 caused an increasing in the ultimate load and the measured maximum deflection.