Experimental research of punching shear strength on reinforced concrete test samples

The article presents the results of experimental studies on the samples of flat reinforced concrete slabs of a girderless frame under the punching by columns of round, square and rectangular cross-section. The description of sample design, the results of determining the physical and mechanical characteristics of materials, as well as the test procedure are given. The results of testing the samples are given. A comparative analysis of the experimental values of failure loads is performed depending on the shape of the section and the ratio of the column sides. The comparison of the experimental values of failure loads and calculated values determined by normative methods SP 63.13333.2012, ACI 318 and EC 2 shows that the design model of SP 63.13333.2012 gives a good fit to the experimental values for square column and overestimates the punching force for flat reinforced concrete slab at a ratio of the sides of rectangular column more than two. The results of the performed experimental studies show that the design model of SP 63.13333.2012, when calculating for punching, does not take into account the influence of the geometrical shape of the column, which can lead to a decrease in the structural safety of the flat slabs of reinforced concrete floors.