Punching strength of biaxial voided slabs

Abstract

New types of reinforced concrete voided slabs cast in place with plastic void formers need to be researched. One of the most dangerous zones of biaxial voided slabs is the slab-column connec-tion and zones where concentrated loads are applied. A slab can fail from punching shear. The area of the shear section in the punching zone is significantly smaller because of the cavities formed by the void formers. In this study, three types of punching shear zones of voided slabs were analyzed: without voids, with voids, and with voids and solid cross-shapes. Punching shear tests were performed on all types of voided slabs. Calculations were performed according to ACI 318-14 and Eurocode 2 design codes for comparison. A new calculation method was developed for the punching shear bearing capacity of voided slabs based on the Eurocode 2 design code. The method was verified according to the actual test results and the results of other authors.