Slab-column edge connections subjected to high moments

1998 ◽  
Vol 25 (3) ◽  
pp. 526-538 ◽  
Author(s):  
E F El-Salakawy ◽  
M A Polak ◽  
M H Soliman
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Punching Shear ◽  
Shear Behaviour ◽  
Shear Reinforcement ◽  
Plate Edge ◽  
Design Procedures ◽  
Test Parameters ◽  
The Moment ◽  
Identical Series

This paper presents test results of eight large-scale reinforced concrete flat plate edge connections. The test specimens consisted of two identical series. Each series consisted of four specimens, two with openings, in the vicinity of the column, and the other two without openings. One of the specimens without an opening contained shear studs as shear reinforcement. The tests were designed to study the effect of high moment-to-shear ratio on the punching shear behaviour of the slab-column edge connections with openings. Each series was subjected to a different moment-to-shear ratio. The test parameters were the location of openings around the column, the shear reinforcement, and the moment-to-shear ratio. The openings in the specimens were square with the sides parallel to the sides of the column. The square dimension of the openings (150 × 150 mm) was 60% of the square column dimension. The slabs contained typical flexural reinforcement (ACI 318-95 and CSA A23.3-94) with the additional reinforcement added on the sides of the openings (equivalent to that interrupted by an opening). The design procedures in the Canadian and American codes (CSA A23.3-94 and ACI 318-95) are discussed and compared with the test results.Key words: columns, edge connections, flat concrete plates, punching shear, shear strength, high moments, openings, failure, shear reinforcement, reinforced concrete.

Reinforced concrete slab-column edge connections with shear studs

2000 ◽  
Vol 27 (2) ◽  
pp. 338-348 ◽  
Author(s):  
Ehab F El-Salakawy ◽  
Maria Anna Polak ◽  
Monir H Soliman
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Concrete Slab ◽  
Punching Shear ◽  
Test Results ◽  
Shear Reinforcement ◽  
Reinforced Concrete Slab ◽  
Test Parameters ◽  
Flexural Reinforcement ◽  
Large Scale Tests

The paper reports the results of an experimental investigation on the influence of shear studs on the behaviour of reinforced concrete slab-column edge connections with openings. The test parameters were the location of openings around the column, the size of openings, and the existence of shear reinforcement. The objective of the paper is to present and discuss the results of large-scale tests on slabs with shear stud reinforcement and compare these test results with those of tests on identical slabs but without shear reinforcement. All tested slabs contained same amounts of typical flexural reinforcement (ACI 318-95 and CSA A23.3-94). The presented test results can be used for studying the behaviour of slab-column connections and for calibration of the predictive models.Key words: reinforced concrete, edge connections, flat concrete plates, punching shear, shear strength, openings, failure, shear studs, shear reinforcement.

scholarly journals Punching Shear Strength of Reinforced Concrete Flat Plates with GFRP Vertical Grids

2021 ◽  
Vol 11 (6) ◽  
pp. 2736
Author(s):  
Min Sook Kim ◽  
Young Hak Lee
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Test Results ◽  
Shear Reinforcement ◽  
Flat Plates ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Vertical Grids

In this study, the structural behavior of reinforced concrete flat plates shear reinforced with vertical grids made of a glass fiber reinforced polymer (GFRP) was experimentally evaluated. To examine the shear strength, experiments were performed on nine concrete slabs with different amounts and spacings of shear reinforcement. The test results indicated that the shear strength increased as the amount of shear reinforcement increased and as the spacing of the shear reinforcement decreased. The GFRP shear reinforcement changed the cracks and failure mode of the specimens from a brittle punching to flexure one. In addition, the experimental results are compared with a shear strength equation provided by different concrete design codes. This comparison demonstrates that all of the equations underestimate the shear strength of reinforced concrete flat plates shear reinforced with GFRP vertical grids. The shear strength of the equation by BS 8110 is able to calculate the punching shear strength reasonably for a concrete flat plate shear reinforced with GFRP vertical grids.

Punching Shear Capacity of Steel Fiber Reinforced Concrete Slab- Column Connections

2019 ◽  
Author(s):  
Josef Landler ◽  
Oliver Fischer
Keyword(s):  
Reinforced Concrete ◽  
Steel Fiber ◽  
Fiber Type ◽  
Fiber Content ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Punching Shear ◽  
Slab Thickness ◽  
Shear Reinforcement ◽  
Fiber Reinforced

<p>To design flat slabs directly supported on columns, the punching shear resistance of the slab is a main factor. It can be increased in the vicinity of the slab-column connection with punching shear reinforcement, like bent up bars or shear studs, to bear the high reaction forces. However, the usage of punching shear reinforcement requires the knowledge of special design rules and often leads to problems and deficiencies in construction.</p><p>Fiber reinforced concrete seems to be a promising alternative to conventional punching shear reinforcement. To investigate the load bearing behavior of the slab-column connection using fiber reinforced concrete, a total of eight punching shear tests were performed. The specimens were realized with a typical top and bottom flexural reinforcement, but without punching shear reinforcement. Varied parameters were the slab thickness with 250 mm and 300 mm and the fiber content V<sub>f</sub> with 0.5 Vol.-% and 1.0 Vol.-%. To investigate the influence of modern fiber types, normal- and high-strength steel fibers with normal- and double-hooked-ends were used.</p><p>In all eight experimental tests, the intended punching shear failure was achieved. The capable load using fiber reinforced concrete increased by 20 % to 50 % compared to the reference tests without steel fibers, depending on the fiber type and the fiber content V<sub>f</sub>. Additionally, this load increase was accompanied by a significant improvement in ductility. The post-cracking behavior was noticeably influenced by the used steel fiber type. An influence of the slab thickness or steel fiber type on the shear strength contributed by the fiber reinforced concrete could not be determined.</p>

Punching Shear Strengthening at the New Station Square in Berne, Switzerland

2010 ◽  
pp. 35-56
Author(s):  
Dominic Joray ◽  
Martin Diggelmann
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Shear Strengthening ◽  
Reinforced Concrete Slab

<p>The reinforced concrete slab of the reconstructed Station Square in Berne needed to be strengthened against punching shear. The case study led to the application of a newly developed post-installed punching shear reinforcement with inclined bonded bars.</p>

Punching shear behaviour of shear reinforced concrete slabs

2015 ◽  
Vol 168 (6) ◽  
pp. 402-420 ◽  
Author(s):  
Kyoung-Kyu Choi ◽  
Gia Toai Truong ◽  
Seon-Du Kim ◽  
In-Rak Choi
Keyword(s):  
Reinforced Concrete ◽  
Punching Shear ◽  
Shear Behaviour ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs

Design of shear reinforcement for thick plates using a strut-and-tie model

2010 ◽  
Vol 37 (2) ◽  
pp. 181-194 ◽  
Author(s):  
H. Marzouk ◽  
E. Rizk ◽  
R. Tiller
Keyword(s):  
Shear Failure ◽  
Punching Shear ◽  
Shear Behaviour ◽  
Rational Approach ◽  
Concrete Slabs ◽  
Shear Reinforcement ◽  
Lower Section ◽  
Strut And Tie ◽  
Shear Cracking ◽  
Strut And Tie Model

The strut-and-tie method is a rational approach to structural concrete design that results in a uniform and consistent design philosophy. A strut-and-tie model has been developed to model the punching-shear behaviour of thick concrete plates. This model provides a quick and simple approach to check the punching-shear behaviour. Thick concrete slabs (250–500 mm) without shear reinforcement can exhibit brittle shear failure under a central force and an unbalanced moment. Shear reinforcement has proven to be very effective in preventing such failures. The developed strut-and-tie model has also been used to evaluate the minimum shear reinforcement required to prevent brittle shear failure of two-way slabs in the vicinity of concentrated loads. The strut-and-tie model for symmetric punching consists of a “bottle-shaped” compressive zone in the upper section of the slab depth, leading to a “rectangular-stress” compressive zone in the lower section of the slab depth. Inclined shear cracking develops in the bottle-shaped zone prior to failure in the lower zone. Cracking in the bottle-shaped zone is related to the splitting tensile strength of concrete.

scholarly journals Behaviour of Reinforced Concrete Beams with Wire Mesh As Shear Reinforcement

2019 ◽  
Vol 8 (12) ◽  
pp. 781-784
Keyword(s):  
Reinforced Concrete ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Reinforced Concrete Beams ◽  
Wire Mesh ◽  
Shear Behaviour ◽  
Experimental Program ◽  
Shear Reinforcement ◽  
Loading System ◽  
Shear Performance

This paper presents a study of shear behaviour of reinforced concrete beams. The major parameters used were type of shear reinforcement, namely stirrups alone, wire mesh alone and combination of both wire mesh and stirrups as shear reinforcement. The replacement of wire mesh was done on the basis of weight with stirrups. The experimental program includes four beams. All the beams were tested using two point loading system. It is evident from the result that the use of wire mesh enhanced improved shear performance and bearing capacity in the examined beams. Beams with wire mesh as shear reinforcement and combination of both wire mesh and stirrups exhibited some amount of increase in shear capacity with respect to the beams with stirrups alone as shear reinforcement. Furthermore beams with wire mesh and combination of wire mesh and stirrups as reinforcement exhibited less number of crack patterns compared beams with stirrups.

scholarly journals New Methods to Resisting Punching Shear Stress in Reinforced Concrete Flat Slabs

2018 ◽  
Vol 8 (02) ◽  
Author(s):  
Fatma M. Eid ◽  
Tayel Magdy ◽  
Ebada Ahmed
Keyword(s):  
Reinforced Concrete ◽  
Shear Failure ◽  
Shear Capacity ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Reinforcement System ◽  
Strength Concrete ◽  
Flat Slabs ◽  
The Difference ◽  
Compact Strength

Punching shear failure is a major problem encountered in the design of reinforced concrete flat slabs. The utilization of shear reinforcement via shear studs or other means has become a choice for improving the punching shear capacity. In this study, a new alternative of reinforcement modalities were tested and demonstrated the effect of self-compact concrete on the punching shear capacity, beside that compared between the difference codes to identify the suitable one for determining the position of critical section of punching shear. Nevertheless, in this investigation, the proposed reinforcement system is examined for interior columns only. An experimental work consisting of six specimens: five of them were cast with normal reinforced concrete and one was cast with self-compact strength concrete. The obtained results indicate that the proposed shear reinforcement system has a positive effect in the enhancement of the punching shear capacity of interior slab–column connection of self-compact strength concrete.

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