Browsing by Subject "Slab-column connection"

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Inclined shear reinforcement in reinforced concrete slab-column connections
(2016-05) Glikman, Mario; Hrynyk, Trevor; Bayrak, Oguzhan, 1969-
Reinforced concrete flat slabs are widely used in modern infrastructure. Due to their comparatively simple construction, flat slabs have become especially prevalent in mid- to high-rise buildings. The performance of slab-column connections has been critically studied over the last several decades by researchers aiming to better understand the behavior of flat slabs subjected to punching shear loading conditions. As a result, the use of slab shear reinforcement has emerged as a practical strategy to improve both the strength and ductility of reinforced concrete flat slabs. The primary objective of this research study was to investigate the behavior of reinforced concrete slab-column connections employing a novel shear reinforcement system consisting of inclined deformed steel reinforcing bars. Results are presented from an experimental program conducted at the Ferguson Structural Engineering Laboratory of The University of Texas at Austin. The results show that a premature failure attributed to inadequate shear reinforcement anchorage controlled the performance of the strengthened slabs. Lastly, a study of the bond stress development in the slab shear reinforcement was carried out to investigate whether this anchorage-driven failure can be captured using different provisions currently available for the assessment of reinforced concrete flat slabs.
Punching shear of reinforced concrete flat plates : behavior and design considerations
(2018-05) Polo Gonzalez, Gabriel Eduardo; Hrynyk, Trevor; Bayrak, Oguzhan, 1969-; Clayton, Patricia; Murcia Delso, Juan; Ghannoum, Wassim
The use of flat plates (i.e., slabs without capitals, drop panels, or supporting beams) in reinforced concrete (RC) building construction has become widespread throughout much of the world. In comparison to other slab types, RC flat plates are often more efficient from a construction standpoint due to their simplified geometries and reduced formwork requirements. However, the complexities of the load transfer mechanisms developed in these systems are still not fully understood. The research presented in this dissertation was aimed toward expanding the current knowledge regarding the punching shear behavior of RC flat plates by investigating the response of slab-column connections under highly-controlled two-way shear loading conditions. The influence of through-thickness shear reinforcement, longitudinal reinforcement ratio, and connection region loading conditions have been investigated and presented in three technical papers which summarize the key findings obtained from the testing of twelve full-scale connection specimens and the supplemental analytical efforts. In the first paper, the performance of RC flat plates employing an alternative shear reinforcement system consisting of inclined deformed reinforcing bars is compared to slabs constructed with conventional reinforcement. The findings showed that premature failures attributed to inadequate reinforcement anchorage controlled the performance of the slabs and limited the benefit provided by the inclined stirrups. In the second paper, the punching shear performance of headed stud reinforced slabs that were constructed with either a cruciform or a radial stud layout, was investigated. Results showed that both shear stud layouts improved the shear-resisting behaviors of the slabs and produced structural responses that were comparable in nearly all aspects. In the third paper, slabs subjected to different sectional loading conditions were examined to assess the influence of loading composition on flat plate shear resisting performance. Experimental work was complimented with numerical analyses and the results indicated that the punching shear response of flat plates is greatly influenced by flexural demands. Further, it was found that the loads experienced by slab specimens tested using common procedures may not be representative of loading conditions experienced by flat plates in service.