The Experimental And Theory Research On Shearing Of Beam In Steel-Reinforced Concrete Beam-Column Joint Under Reversed Cyclic Load

Shear capacity for steel-reinforced concrete beam was effected by many factors, such as shear span ratio, ways of loading, concrete strength, sectional steel area ratio and steel strength, hoop reinforcement ratio and hoop reinforcement strength, steel flange ratio, thickness of concrete protecting steel flange and situation of reinforcement in nodal point. Because the mechanism of shear influenced by many factors is complex, the computation theory and methods of shear are not consistent with each other in world, and the research on shearing under cyclic load is less than others. Through test, this study investigates the shear strength, ductility, energy dissipation, rigidity and the hysteretic character of steel-reinforced concrete beams subjected to cyclic load in which the shear-span ratio or hoop reinforcement ratio is different from others.First, The test of steel-reinforced concrete beams subjected to cyclic load is done. The process of test is described in detail, and the results of test are analyzed in simple. The types of shear failure are analyzed and categorized. Bearing capacity and displacement of specimens are given. Strain distributions and stress conditions of specimens are analyzed. It provided a lot of test data for the further research on shear strength and seismic character of steel-reinforced concrete beam.Secondly, based on concrete compression-shear strength criterion and analysis of the experimental results, a formula of shear capacity of steel-reinforced concrete beam subjected to cyclic load is derived by equilibrium equations and by deformation conditions. The test results are in good agreement with the formula. The shear bond failure is analyzed and a new term, the critical steel flange ratio(bf/b)cr, is introduced to prevent the possible shear bond failure.Finally, according to the test results, hysteretic and skeleton curves of the SRC beams subjected to cyclic load are obtained. Based on these curves, ductility, energy dissipation and rigidity degradation rules are analyzed. And a skeleton model is proposed for non-linear analysis.