Effects of openings on the punching shear strength of RC flat-plate slabs without shear reinforcement

2015 ◽  
Vol 24 (15) ◽  
pp. 895-911 ◽  
Author(s):  
Taehun Ha ◽  
Myung-Ho Lee ◽  
Jonghwan Park ◽  
Dae-Jin Kim
Keyword(s):  
Shear Strength ◽  
Flat Plate ◽  
Punching Shear ◽  
Shear Reinforcement

The Effect of Anchorage Strength with Anchorage Capacity in Flat Plate

2014 ◽  
Vol 627 ◽  
pp. 245-248
Author(s):  
Hyun Ki Choi
Keyword(s):  
Shear Strength ◽  
Flat Plate ◽  
Shear Failure ◽  
Punching Shear ◽  
Slab Thickness ◽  
Shear Reinforcement ◽  
Strength Formula ◽  
Test Result ◽  
Plate System ◽  
Structure Test

The punching shear on the flat plate slab-column connection can bring about the reason of the brittle punching shear failure which may result of collapsing the whole structure. From the development of residential flat plate system, the shear reinforcement is developed for preventing the punching shear. This study proposed 3 reinforcements that are increased to bond capacity using lateral bar, the structure test is performed. As performed test result, because slabs not keep enough bond length, slab is failed before shear reinforcement's yield strength duo to anchorage of slip. According to result, FEM analyzed an effect of slab thickness and concrete compressive. The study suggests shear strength formula that possible a positive shear reinforcement in slab-column connection.

scholarly journals Failure analysis of column–slab connections with stud shear reinforcement

2003 ◽  
Vol 30 (5) ◽  
pp. 934-944 ◽  
Author(s):  
Hong Guan ◽  
Yew-Chaye Loo
Keyword(s):  
Finite Element ◽  
Shear Strength ◽  
Flat Plate ◽  
Large Scale ◽  
Punching Shear ◽  
Slab Thickness ◽  
Shear Reinforcement ◽  
Element Analysis ◽  
Reinforced Concrete Slabs ◽  
New Type

The design of a flat plate structure is generally governed either by serviceability limits on deflection or punching shear strength of the column–slab connections. To increase the strength of a column–slab connection, a new type of shear reinforcement, referred to as shear stud, is gaining popularity in practice. In this paper, a nonlinear layered finite element method (LFEM) is used to investigate the effectiveness of the shear studs in increasing the punching shear strength of edge and corner column–slab connections. In total, nine large-scale reinforced concrete slabs of a flat plate floor in the vicinity of edge and corner columns, tested previously in the laboratory, are analysed. All the slabs contained stud shear reinforcement (SSR) except a control slab where no SSR was provided. The test variables were the column size and the ratio of stud spacing to slab thickness. The punching shear strengths, load–deflection responses, and crack patterns predicted by the LFEM are compared with the experimental results. The numerical investigation confirms the accuracy and effectiveness of the LFEM in predicting the strength of column–slab connections with SSR.Key words: column–slab connection, concrete flat plate, punching shear, stud shear reinforcement, finite element analysis.

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.

Rehabilitation of reinforced concrete slab–column connections

2002 ◽  
Vol 29 (4) ◽  
pp. 602-611 ◽  
Author(s):  
Ehab F El-Salakawy ◽  
Maria Anna Polak ◽  
Khaled A Soudki
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Concrete Slab ◽  
Normal Weight ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Shear Reinforcement ◽  
Reinforced Concrete Slab ◽  
Normal Weight Concrete ◽  
Average Compressive Strength

The paper presents work on punching shear rehabilitation and strengthening of existing slab–column connections. Four full-scale specimens representing slab–column edge connections were built and tested to failure. Three slabs were then repaired and strengthened and tested again. In the originally tested slabs, which were chosen for repair, one slab had an opening in front of the column and contained shear reinforcement, one slab had an opening and no shear reinforcement, and one had no opening and no reinforcement. The dimensions of the slabs were 1540 × 1020 × 120 mm with square columns (250 × 250 mm). The openings in the specimens were square (150 × 150 mm) with the sides parallel to the sides of the column. The slabs were made using normal weight concrete (28-day average compressive strength of 32 MPa) and reinforced with a reinforcement ratio of 0.75%. The slabs were repaired by replacing old-damaged concrete with new concrete of the same properties. Strengthening was carried out using shear studs for the two slabs, which originally did not have shear reinforcement. The rehabilitation increased the punching shear strength (by 26–41%) and the ductility of the connections. All repaired specimens failed in flexure.Key words: concrete slabs, punching shear, rehabilitation, edge connections, openings, studs, repair.

scholarly journals Punching Shear Strength Characteristics of Flat Plate Panels Reinforced with Shearhead Collars: Experimental Investigation

2019 ◽  
Vol 5 (3) ◽  
pp. 528 ◽  
Author(s):  
Maroua Mohammed Majeed ◽  
Aamer Najim Abbas
Keyword(s):  
Experimental Investigation ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Flat Plate ◽  
Energy Absorption ◽  
Concrete Slab ◽  
Shear Capacity ◽  
Load Test ◽  
Punching Shear ◽  
Reference Specimen

This paper presents an experimental investigation on the punching shear strength of reinforced concrete flat plate slabs with shearhead collars. Eight reinforced concrete slab specimens were casted and tested under static load test, the load was applied at the center of slab by 100x100 mm steel column. The effect of the shapes, diameter and number of stiffeners has been discovered for shearheads through studying its effect on the load-deflection behavior, ultimate capacity, cracking load, failure mode, stiffness, ductility and energy absorption of tested specimens. The experimental results indicates that using square shearhead had achieved a slight increase in punching shear strength about 3% over that circular shearhead using the same surface area. Also, utilize 550 mm shearhead diameter will contribute to increase the punching shear strength about 14.5%. The increase in the number of stiffeners in specimen (CS4) had reduced the ultimate punching shear capacity by 20.3% over reference specimen. The first crack was decreased from 12.5kN to 7.5kN, when increases the number of stiffeners from one to two. The cracking load was increased with the increase of the diameter of circular shearhead from 10kN to 15Kn in specimens of 336mm and 550mm respectively. The specimen with 336mm diameter and 30mm height circular shearhead achieved 427 kN.m energy absorption, it is higher than the energy absorption of reference specimen by 2.6%. Also, using two stiffeners improved the energy absorption by 110.2% higher than the specimen with one stiffener.

An Experimental Study on Shear Reinforcement Methods of Interior Flat Plate-Column Connections

2008 ◽  
Vol 385-387 ◽  
pp. 857-860
Author(s):  
Hyun Ki Choi ◽  
J.S. Kim ◽  
E.S. Jin ◽  
Chang Sik Choi
Keyword(s):  
Experimental Study ◽  
Flat Plate ◽  
Shear Failure ◽  
Shear Capacity ◽  
Punching Shear ◽  
Vertical Shear ◽  
Shear Reinforcement ◽  
Plate Structures ◽  
Shear Reinforcements ◽  
Plate Column

This research is an experimental study on full-scale interior slab-column connections of flat-plate. Three types of shear reinforcements were proposed to prevent brittle punching shear failure that could result in collapse of whole flat plate structures. A series of four flat plate specimens including a specimen without shear reinforcement and three specimens with the reinforcements was tested. The dimension of the slabs was 2620*2725*180mm and the specimens had a 600*800mm square column at the center of the slabs. The slabs were tested up to failure using monotonic vertical shear forces. The presences of the shear reinforcements substantially increased punching shear capacity and ductility of the interior slab-column connections.

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