Finite element analysis of high-strength concrete flat slab with openings

Abstract

Reinforced concrete slabs are an important component of high-rise buildings as they are designed to withstand the loads they are subjected to. Concrete slabs, on the other hand, may fail due to punching shear, which is one of the most serious risks in the slab column connection. This kind of failure, which is difficult to predict, occurs almost instantaneously and can have disastrous consequences. This research aims to examine how high-strength flat slabs act under vertical loads, as well as how openings affect flat slab punching shear strength. To do so, ABAQUS uses a series of non-linear numerical models to simulate the punching shear effect on reinforced concrete flat slabs and to investigate the effects of the various sizes and locations of the openings and the constitutive modeling of concrete on the punching shear stress of the connections. To begin with, the experimental results of Marzouk and Chen were used to perform the initial calibration of the finite element model. The effect of the openings presents in a flat slab with different positions and sizes and distances of 0d, 1d, 2d, 3d, 4d, and 5d far from the column in parallel position was determined by the analysis of 42 internal connections under incremental vertical load, while the connection without opening was used as a reference in each case. The shear strength was reduced by up to 9.6 percent as a result of an opening located at 2d distance from the column. This result is unaffected by the number of openings. The experimental and numerical results are also used to evaluate the accuracy of the various code equations available for predicting flat slab punching shear capacity. Eurocode prediction is more accurate than Canadian standard.