الفهرس | Only 14 pages are availabe for public view |
Abstract Flat plate system is a slab system commonly used in modern structures. In this approach, slabs are directly supported by columns, without the use of beams. Thus, punching shear failure is one of its modes of failure that should be avoided especially it is a sudden failure mechanism. As a result, the behavior of flat slabs subjected to punching stress is a critical topic in design, specifically for edge connection, because of exposure to shear stresses resulting from both unbalanced moments and vertical loads. The main objective of this thesis is to study the punching shear behavior under a combination of unbalanced moment and vertical force in the case of an edge column. An experimental program was conducted on seven reinforcement edge column-slab connections. All tested slabs had the same dimensions (1600 mm x 1000 mm x 100 mm), concrete strength (43 N/mm2), longitudinal reinforcement ratio (μ= 1.50%), and a clear concrete cover of 20 mm. All slabs were tested using eccentric loading. The main studied variables were the effect of the moment-to-shear ratio (M/V), the effect of changing the column dimension (C2) parallel to the free edge, and the effect of the spandrel beam existence. Finally, a comparison between the experiment failure load and the expected failure load was established based on equations from four international codes (ECP 203-2020, ACI 318-2019, AS 3600-2018, and EN1992-1-1-2004) Test results are presented and discussed. It was concluded that increasing eccentricity reduces the punching shear ultimate load, whereas increasing the column dimension (C2) parallel to the free edge and increasing the spandrel beam dimensions increase the punching shear ultimate load and the connection stiffness. As mentioned by several codes and previous researchers, Spandrel beam height has a great effect on the mode of failure for the edge connection. from the conducted comparison, the proposed equations by the four studied codes give a conservative expected punching shear ultimate load. EN1992-1-1code equations are the closest to the experimental records, while ACI 318 equations are the most conservative. Also, the ECP 203 simplified method should have appropriate limitations to achieve a safe design for large eccentric loading. |