Effect of varying opening size on the punching shear behavior of two-way rc slabs

In this study, the punching behavior of two way reinforced concrete floor slab with change in the size of the opening in the slab is investigated. In this experimental study one specimen without the opening and four specimens with opening are tested. Two way square slabs having the dimensions of 2000*2000*120 mm that were tested under the influence of applied axial load (one column with 200*200 dimension). These slabs have two types of openings in dimension of 300*300 and 500*500 on two different locations (parallel and adjacent with column and diagonal and adjacent with column). As a result of the tests specimens, by examining the ultimate strenght, stiffness and energy consumption that obtained from test, the effects of size of opening of two way slabs performance were interpreted. Ultimate capacity of the test specimens were calculated with ACI 318, Euro code 2, and TS 500 and then were compared with the experimental results. Experimental results have shown a decrease in punching strength when the size of opening increases.