Punching shear resistance of flat slabs with different types of stirrup anchorages such as shear reinforcement

Experimental Evaluation of the Punching Shear Strength of Interior Slab-column Connections with Different Shear Reinforcement Details

“…Figures 11, 12, and 13-b show the schematic crack pattern of group III and specimen S16-IV respectively. The failure surface occurred inside the shear reinforced zone for all specimens except S10-III (Also see Figures 17,18,and 19 (b)). For group I and II specimens, failure crack formation seems to be more steeply inclined compared to S1.…”

“…They found that there is good enhancement in post-punching performance of junction when reversing loading direction. De Oliveira et al [18] tested nine interior slab-column connections with variable anchorage detailing of closed stirrups. They concluded that the punching shear resistance and the behavior of the slabs were not affected by the change in anchorage conditions.…”

Punching shear in flat slabs with open stirrups as shear reinforcement

“…However, EC2 predicted failures at the perimeter outside the shear reinforcement region for all slabs, as the estimations for failure inside the shear reinforcement region would be 635, 629, 634, and 618 kN for slabs FA, TA, CA, and NA, respectively. The nine slabs tested by Lima et al 43 (2), by Oliveira et al 46 (2), and by Vollum et al 49 (5) used closed stirrups with full anchorage at the tension and at the compression flexural reinforcement. The five slabs by Lips 50 adopted cages of continuous stirrups as shear reinforcement, while Regan and Samadian 47 tested two slabs with shear links with 180 bends over the lower layer of the top reinforcement.…”

“…The nine slabs tested by Lima et al 43 (2), by Oliveira et al 46 (2), and by Vollum et al 49 (5) used closed stirrups with full anchorage at the tension and at the compression flexural reinforcement. The five slabs by Lips 50 adopted cages of continuous stirrups as shear reinforcement, while Regan and Samadian 47 tested two slabs with shear links with 180° bends over the lower layer of the top reinforcement.…”

“…Comparisons with respect to the type of shear reinforcement are very hard, as many parameters interfere on the behavior of the slabs, like the ratio of flexural and shear reinforcement, and so on, having said that, the highest increase compared with its reference slabs was obtained by Lips 50 (53%–89%), followed by Regan and Samadian 47 (57%–65%), and by Vollum et al 49 (21%–48%) and Siqueira 48 (25%–45%), and by Oliveira et al 46 (17%–31%) and Lima et al 43 (12%–27%).…”