Estimativa da força de ruptura à punção em ligações laje-pilar interno sem armadura de cisalhamento de estruturas em concreto armado via modelos de regressão múltipla

Abstract

The structural systems critical point of flat slabs happens on the connection slab-column through the shearing stressing concentrations which may lead to the punching phenomenon. According to the literature, there are multiples factors that influence on the punching phenomenon, and many theoretical and experimental research have been developed willing to comprehend its behavior and then estimate the connection slab-column punching resistance. However, yet there is no sizing model completely accept by the technical scientific community which is able to estimate and explain such phenomenon and all of its influence parameters. In this context, this study aims proposing, by statistical analysis applied to experimental studies, a limit punching tensile strength predictor equation of the internal slab-column connection, with no shear reinforcement and symmetrical loading, on reinforced concrete edifications. Therefore, it has been evaluated the punching resistance predictor models presented by the literature and the mainly norms through a vast database containing the manly punching influencers parameters. The proposed model, based on only five real model variables – Slab geometry (Geo), Pillar dimension (L), useful slab height (d), concrete compression resistance (fc) and bending bar rate (ρ) – estimated the limit punching tensile strength (Pu) on internal slab-column connection with a 3% error order and R2 adj = 97.28%.