Numerical study on the effect of different column shapes on punching shear behavior of flat slabs

This study was carried out to assess the punching shear behavior of flat slabs considering the use of various column shapes such as L, T, and Cruciform as support. The flat slab floor system is becoming most adopted in various structures ranging from medium-rise to skyscrapers, garages, factories, airports, etc. Although in this field of study, various research has been carried out over the decade, limited considerations were made for compound column geometries. Finite Element modelling software Abaqus was used in the development of a numerical model capable of predicting punching shear features of flat slabs. The control model was a flat slab supported on a square column established from an experimental test reported in previously published literature. The concrete material behaviour was defined in the Concrete Damage Plasticity Model and the best-suited parameters were deduced by sensitivity analysis. A comparative analysis was performed to compare the numerical results to both experimental and code predictions from ACI 318-19, Eurocode 2, 2004 and Model Code 2010. The study revealed that the shape of columns influences the punching shear capacity, with L, T, and Cruciform giving an increase of 3%, 5.2% and 22.6% respectively.