Effect of load level of corner columns on punching shear resistance of flat slabs
The problem related to the effect of the corner column load on the punching shear resistance of the slab was presented. Existing experimental studies on internal columns demonstrated that the column pressure could lead to an increase in the punching shear resistance. Because of different confinement conditions of corner column-slab connection joints, it is unclear if such an effect exists for corner columns. New experimental investigations were initiated to clarify this issue. They covered a total of three corner column-slab connection specimens – slabs with a thickness of 140 mm and a longitudinal reinforcement ratio ρl = 1.09% connected with columns of a cross-section of 200×200 mm. The only variable parameter was the column load equal to 500, 1000 and 1500 kN.
A reduction of the slab load-carrying capacity of about 9% due to a three-fold increase in the column load was noted. Therefore, the effect of the column load turned out to be opposite to that observed for most previous tests on internal column-slab connections, which could have a result of a limited capacity of the slab reinforcement due to additional tensile forces from the lateral expansion of joint concrete.
Comparison in the light of test results demonstrated, that EN 1992-1-1 procedure allowed for safe, yet conservative estimation of the punching shear resistance. An average ratio of experimental to theoretical load of 1.82 was obtained.
column-slab connections; punching shear; lateral expansion; membrane action; normal stress
Urban T. S. and Gołdyn M. M., “Behaviour of eccentrically loaded high-strength concrete columns intersected by lower-strength concrete slabs,” Structural Concrete, vol. 16, no. 4, (Dec. 2015), pp. 480–495. https://doi.org/10.1002/suco.201400114
Gołdyn M. et al., “Carrying Capacity of Axially Loaded HSC Columns Intersected by NSC Slab,” Architecture • Civil Engineering • Environment – ACEE, vol. 8, no. 3, (2015), pp. 51–60.
Guidotti R. et al., “Crushing and flexural strength of slab-column joints,” Engineering Structures, vol. 33, no. 3, (Mar. 2011), pp. 855–867. https://doi.org/10.1016/j.engstruct.2010.12.007
Guidotti R. et al., “Durchstanzen von Flachdecken bei hohen Stützenlasten,” Beton- und Stahlbetonbau, vol. 105, no. 1, (Jan. 2010), pp. 19–26. https://doi.org/10.1002/best.200900066
Clément T. et al., “Influence of prestressing on the punching strength of post-tensioned slabs,” Engineering Structures, vol. 72, (Aug. 2014), pp. 56–69. https://doi.org/10.1016/j.engstruct.2014.04.034
Ramos A. P. et al., “The effect of the vertical component of prestress forces on the punching strength of flat slabs,” Engineering Structures, vol. 76, (Oct. 2014), pp. 90–98. https://doi.org/10.1016/j.engstruct.2014.06.039
Urban T., Przebicie w żelbecie: wybrane zagadnienia. Łódź: Zeszyty Naukowe. Rozprawy Naukowe / Politechnika Łódzka, 2005.
EN 1992-1-1: Eurocode 2: Design of concrete structures - Part 1-1: General rules and rules for buildings, Brussels: European Committee for Standardisation, 2004.
Gołdyn M. and Urban T., “Komentarz do zasad obliczania płyt na przebicie w strefie słupów narożnych według Eurokodu 2,” Journal of Civil Engineering, Environment and Architecture, vol. 64, no. 3, (2017), pp. 235–245. https://doi.org/10.7862/rb.2017.118
This work is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Budownictwo i Architektura supports the open science program. The journal enables Open Access to their publications. Everyone can view, download and forward articles, provided that the terms of the license are respected.
Publishing of articles is possible after submitting a signed statement on the transfer of a license to the Journal.