Comparative Research On Punching Shear Failure And Shear Failure Of Reinforced Concrete

Slab-column structure of reinforced concrete has been increasingly used in actural project, and its mechanical performance has drawn much people’s attention. Many scholars through tests found that it’s easy to form a punching cone convex surface and then punching shear failure occurs. Many engineering accidents occurred in the past indicate that the destruction may be due to a chain reaction caused by the collapse of the whole. Because of punching shear damage has great harm to itself, so it has been the most important issue that how to improve punching shear performance of slab so as to avoid damage occurs. Based on summarizing predecessors’ tests and combined with ANSYS finite element software, the systematic research is done to analyze punching shear resistance of slab-column structure of reinforced concrete, the main work as follows.First of all, the analysis is done to reinforced concrete unidirectional and two-way slab under the concentrated reaction occurred shear failure and the punching failure mechanism and characteristic, comparatively analyze punching and bending, shear failure, and achieve the relation and distinction between them.Second, comparative analysis of the punching shear capacity formulation is done among GB50010-2010, ACI318-08and EN1992-1-1:2004Concrete specification, some main factors that affect the punching strength is summarized and analyzed by test datas, and point out that increase ffective thickness has a more obvious influence on improvement of punching shear strength. After summarize punching shear resistance measures of the reinforced concrete slab, points out some advantages and disadvantages of them to provide a reference for punching shear resistant design.Last, applying ANSYS finite element software as analysis tool to special-shaped slab-column connections by nonlinear simulation to achieve ultimate capacity and displacement change with expansion of the crack, then find it fit test results. According to the shape of cracks distribution, the critical perimeter formulation of different column section is achieved, in contrast the multi-group simulation value, thought under the same level condition, the different shape column slab-column structure has compared to rectangular column higher shear capacity.