scholarly journals The analysis of the effectiveness of different types of punching shear reinforcement not fully anchored

2013 ◽  
Vol 12 (1) ◽  
pp. 195-202
Author(s):  
Tadeusz Urban ◽  
Michał Gołdyn ◽  
Łukasz Krawczyk
Keyword(s):  
Load Capacity ◽  
Point Of View ◽  
Experimental Results ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Flat Plates ◽  
Eurocode 2 ◽  
Different Types

The paper discusses the issue of load capacity of flat plates with transverse reinforcement situated between the longitudinal reinforcement. Using this types of reinforcement is much more convenient from the installation point of view, however, it does not guarantee complete embedment, as efficient as traditional stirrups that comprise longitudinal reinforcement in compression and the tension zone. The transverse rods do not comprise the main reinforcement, so their slide out of the concrete slabs or cracks parallel to the plane of the longitudinal reinforcement and delamination of the slab can occur. The different types of transverse reinforcement were presented: system consisting of  ready-made bolts, reinforcement baskets or ladders. Experimental results of plates with  these types of reinforcement are presented. The analysis of effectiveness of reinforcement anchorage indicates that transverse bolts can be used to increase the punching shear load capacity of the plates. The resulting capacity was only of about 20% lower than result elements with complete embedment Experimental results were similar to the theoretical capacity resulting from the consideration by Eurocode 2.

scholarly journals Investigation of longitudinal reinforcement contribution in shear punching of reinforced concrete flat slabs without transverse reinforcement

2019 ◽  
Vol 279 ◽  
pp. 02005
Author(s):  
Vladimir Alekhin ◽  
Alexander Budarin ◽  
Maxim Pletnev ◽  
Liubov Avdonina
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Load Capacity ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Factors Affecting ◽  
Codes Of Practice ◽  
Reinforced Concrete Slabs

The shear punching of the reinforced concrete slabs is a complex process occurring when considerable force is concentrated on the relatively small area of a column-slab connection. An incorrect assessment of load capacity of slab under the punching shear may lead to an accident. One of the most significant factors affecting the slab capacity is longitudinal reinforcement. In this article much attention is given to the analysis of the longitudinal rebar impact on the maximum loading capacity of reinforced concrete slabs without transverse reinforcement affected by punching shear force using the finite element method. The results obtained via the finite element simulation are compared with laboratory tests and manual calculations carried-out using various methods represented in different national building Codes of practice.

scholarly journals Experimental investigations of punching shear concrete slabs with different types of transverse reinforcement

2014 ◽  
Vol 13 (3) ◽  
pp. 193-200
Author(s):  
Tadeusz Urban ◽  
Łukasz Krawczyk ◽  
Michał Gołdyn
Keyword(s):  
Load Capacity ◽  
Punching Shear ◽  
Experimental Program ◽  
Experimental Investigations ◽  
Concrete Slabs ◽  
Transverse Reinforcement ◽  
Shear Load ◽  
Test Results ◽  
Different Types ◽  
Flexural Reinforcement

The results of support zone thick concrete slabs experimental investigation are presented in the paper. The experimental program consisted of 4 square reinforced concrete flat models to 1:2 scale made of the same concrete with the same dimensions and the same flexural reinforcement. The aim of tests was proved the influence of different transverse reinforcement types on punching shear load capacity. One of the models was a comparative slab made without transverse reinforcement. In the other slabs three types of transverse reinforcement were used: typical stirrups enclosing flexure reinforcement, stirrups situated between flexure reinforcement and ladders. The test results show a few percent difference in load capacity between models with transverse reinforcement, the most effective were typical stirrups enclosing the main reinforcement.

scholarly journals Shear Cap Size Selection Method Based on Parametric Analysis of ACI-318 Code and Eurocode 2 Standard

Materials ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 4938
Author(s):  
Maciej Grabski ◽  
Andrzej Ambroziak
Keyword(s):  
Parametric Analysis ◽  
Load Capacity ◽  
Selection Method ◽  
Shear Capacity ◽  
Punching Shear ◽  
Transverse Reinforcement ◽  
Shear Load ◽  
Reinforced Concrete Structure ◽  
Practical Application ◽  
Eurocode 2

The scope of the paper is to propose a method for determining the size of shear caps in a slab–column-connections-reinforced concrete structure. Usually, shear heads are used to enhance slab–column connection, especially when the transverse reinforcement does not give the required punching shear load capacity. The dimensions of the shear head should provide the punching shear resistance of the connection inside and outside the enhanced region. The process of selecting the size of the shear head is iterative. The parametric analysis of the ACI 318 code and EC2 standard has the objective of indicating which control perimeter (inside or outside the shear head) has a decisive impact on the punching shear capacity of the connection. Based on the analysis, the authors propose methods for selecting the dimensions of the shear head with practical application examples. The paper is intended to provide scientists, civil engineers, and designers with guidelines to design the process of the slab–column connections with the shear caps.

scholarly journals Punching shear resistance of reinforced concrete footings: evaluation of design codes

2018 ◽  
Vol 11 (2) ◽  
pp. 432-454
Author(s):  
D. F. A. SANTOS ◽  
A. F. LIMA NETO ◽  
M. P. FERREIRA
Keyword(s):  
Reinforced Concrete ◽  
Progressive Collapse ◽  
Shear Resistance ◽  
Test System ◽  
Shear Capacity ◽  
Experimental Results ◽  
Punching Shear ◽  
Complex Method ◽  
Shear Design ◽  
Eurocode 2

Abstract Punching is a possible failure mode for slender footings and it may lead a structure to ruin through progressive collapse. Although footing present different geometric characteristics, their punching shear design is based on the empirical methods used for flat slabs. This paper uses experimental results from 216 tests to evaluate the performance of design code recommendations presented by ACI 318 (2014), ABNT NBR 6118 (2014) and Eurocode 2 (2010) to estimate the punching shear resistance of reinforced concrete footings. Great dispersion between theoretical and experimental results was observed, being evident that the test system affects the punching shear capacity of footings. The more complex method proposed by Eurocode 2 resulted in a better correlation with experimental results.

Distribution of moments in reinforced concrete slabs with continuous drop panels

2002 ◽  
Vol 29 (1) ◽  
pp. 119-124
Author(s):  
Patrick Paultre ◽  
Caroline Moisan
Keyword(s):  
Reinforced Concrete ◽  
Analytical Study ◽  
Concrete Slab ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Flat Plates ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs ◽  
Moment Distribution ◽  
The Moment

Slabs with continuous drop panels between column lines facilitate formwork, make long spans possible in addition to increase punching shear resistance around supports and provide unobstructed spans with minimum structural floor depth resulting in lower floor-to-floor heights. The moment distribution in such slabs is different from that in conventional flat plates or slabs with drop panels systems. Dimensioning according to the current provisions in CSA A23.3-94 is problematic because the continuous drop panels are subject to moments exceeding the minimum values allowed by the Code for conventional slab systems. This analytical study presents the moment distribution in slabs with continuous drop panels in an attempt to provide more realistic transverse moment distribution factors.Key words: reinforced concrete, slab systems, slab design, drop panel, moment distribution.

scholarly journals Slabs strengthened for punching shear with post-installed steel and CFRP connectors

2019 ◽  
Vol 12 (3) ◽  
pp. 445-478
Author(s):  
M. J. M. PEREIRA FILHO ◽  
M. V. P. FREITAS ◽  
D. F. A. SANTOS ◽  
A. J. C. NASCIMENTO ◽  
M. P. FERREIRA
Keyword(s):  
Shear Resistance ◽  
Experimental Results ◽  
Punching Shear ◽  
Design Codes ◽  
Shear Reinforcement ◽  
Shear Strengthening ◽  
Flat Slab ◽  
Design Recommendations ◽  
Eurocode 2 ◽  
Shear Failures

Abstract Structural accidents due to punching shear failures have been reported in flat slab buildings. Design recommendations presented by codes can lead to entirely different punching shear resistance estimates for similar situations. Furthermore, design codes do not present guidelines for the design of punching shear strengthening of existing slabs. This paper uses a database with 118 experimental results to discuss the performance of theoretical estimates of punching shear resistance using ACI 318, Eurocode 2 and ABNT NBR 6118 in the case of slabs without shear reinforcement. Another database with results of 62 tests on slabs strengthened with post-installed steel and CFRP dowels is used to evaluate the performance of these strengthening techniques and to propose adaptations in codes to allow their use in punching shear strengthening situations of existing slab-column connections.

Flexural and Shear Failure Analysis of Reinforced Concrete Slabs and Flat Plates

1997 ◽  
Vol 1 (1) ◽  
pp. 71-85 ◽  
Author(s):  
Hong Guan ◽  
Yew-Chaye Loo
Keyword(s):  
Reinforced Concrete ◽  
Failure Analysis ◽  
Shear Failure ◽  
Concrete Slab ◽  
Load Capacity ◽  
Concrete Slabs ◽  
Nonlinear Behaviour ◽  
Flat Plates ◽  
Reinforced Concrete Slabs ◽  
Degenerated Shell Element

A nonlinear layered finite element procedure is presented for flexural and shear failure analysis of reinforced concrete slabs and flat plates. A degenerated shell element employing a layered discretization scheme is adopted. This provides a simple and effective means of accounting for the nonlinear behaviour of concrete and steel reinforcement over the thickness of the slab or flat plate. The procedure is capable of determining the load-deflection response, the ultimate load capacity and crack patterns of concrete slab structures, as well as computing the punching shear strength at slab-column connections of concrete flat plates. To verify the accuracy and reliability of the proposed method of analysis, comparative studies are carried out on a collection of reinforced concrete slabs, single slab-column connections and multi-column flat plates which were tested by other researchers. In general, good correlations are obtained with the published test results.

scholarly journals Effect of Shape, Number, and Location of Openings on Punching Shear Capacity of Flat Slabs

Buildings ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 484
Author(s):  
Ekkachai Yooprasertchai ◽  
Yonlada Tiawilai ◽  
Theerawee Wittayawanitchai ◽  
Jiranuwat Angsumalee ◽  
Panuwat Joyklad ◽  
...  
Keyword(s):  
Shear Strength ◽  
Standard Deviation ◽  
Experimental Evidence ◽  
Shear Capacity ◽  
Experimental Results ◽  
Punching Shear ◽  
Minimal Impact ◽  
Flat Slabs ◽  
Analytical Results ◽  
Eurocode 2

Experimental evidence have proved that punching shear capacity of flat slabs deteriorate with the presence of openings located within the critical perimeter around columns. It is understood that this deterioration varies inversely with the distance of openings from column’s face. However, effect of the shape of openings on punching shear capacity is not well known. This study presents experimental results of 14 flat specimens to investigate the effects of the number (2 and 4), shape (circular, square, and rectangular), and location (1 and 4 times of slab’s thickness from column’s face) of openings on punching shear strength. It was found that circular openings had least influence on punching capacity followed by square and rectangular openings, respectively. Further, placing openings at a distance of four times the slab’s thickness from column’s face had minimal impact on punching capacity. Further, increasing the number of openings from 2 to 4 substantially reduced the punching capacity. An effort was made to predict the punching capacities of all specimens using the descriptive equations of ACI 318-19 and Eurocode 2. Mean of the ratio of experimental to analytical results and standard deviation of ACI equations were found to be more accurate than those of Eurocode 2 predictions.

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