Comparison of the Test Results on Flat Slabs Weakened by Openings with Punching Shear Capacities Assessed by the Model in the 2^nd Generation of EC2

Abstract

The paper deals with a comparison of the punching shear capacities of the experimental flat slabs without shear reinforcement weakened by openings adjacent columns with the results obtained by the prEC2 model for prediction punching capacity that is introduced in the second generation of Eurocode 2. Within the experiments, 4 slabs with dimensions of 2.5 m x 2.5 m and with a thickness of 200 mm and 8 slabs with a thickness of 250 mm were tested and evaluated. Specimens with a thickness of 200 mm were supported by an elongated column with dimensions of the column’s cross-section 950 x 150 mm and the second set of specimens with a square column with a dimension of 200 mm. The position of openings around the perimeter of the column as well as the distance from a column face were changing. Assessed punching shear capacities and their comparison with laboratory tests show that the prEC2 model significantly underestimates punching capacity when the opening is located at the face of support or near the shorter side of the elongated column if the reduction of the control perimeter length is steering by a radial projection of the opening.