Analytical study of effective factors on increasing punchingshear strength in reinforced concrete flat slabs connectionswith an opening

Reinforced concrete flat slab is a common structural system, which is widely used in the construction of various buildings. On the other hand, utilization of flat slabs directly resting on columns, in the case of punching shear failure, reveals their vulnerability, especially in seismic areas. Application of flat slab reinforced concrete system was primarily done due to necessity of passing the mechanical and electricalinstallations, in which presence of openings in vicinity of the column is inevitable. The presence of openings reduces punching shear strength of flat slabs. Hence, strengthening the flat slabs with an opening in the slab-column connections has great importance. In the present study, some of the factors affecting punching shear strength of flat slabs with an opening were studied using a numerical method. To validate the numerical model, the obtained results were compared with those of experimental sample. Then, the impact of concrete compressive strength, tensile reinforcement percentage, presence and number of reinforcements in the compressive area, and presence of additional bar around the opening was investigated. It was observed that increasing the level of reinforcement connection, improved the condition of punching shear capacity and stiffness of slabs. Furthermore, by increasing concrete compressive strength, load bearing and ultimate connection deflection increased, as well.

کلیدواژه ها:

Flat slab ، Punching shear strength ، Finite element method ، Opening ، ABAQUS