Punching Shear Capacity of Interior SFRC Slab-Column Connections

The paper deals with the punching shear behavior and the capacity of interior steel fiber-reinforced concrete (SFRC) slab-column connections. In the experimental study, the effect of the amount of fibers on the punching shear resistance and cracking behavior of slabs was investigated on a total of 12 small-scale flat slabs of varying dimensions. The results show a significant increase in the punching shear capacity, reduction of the average crack widths, and improved integrity of the SFRC slab-column connections in the postcracking stage in comparison with conventional reinforced concrete slabs. A new semiempirical, fracture-mechanics-based formula for estimation of the punching shear resistance of the interior SFRC slab-column connections is also presented in the paper. Its accuracy was verified through the comparison of the test results provided by the authors with those of other researchers, as well as with some already published formulas. The obtained results show that the proposed formula provides a higher prediction accuracy of the punching shear capacity of the SFRC slab-column connections in comparison with the existing prediction formulas. DOI: 10.1061/(ASCE)ST.1943-541X.0000497. (C) 2012 American Society of Civil Engineers.