Activation model for various punching shear reinforcement types in flat slabs and column bases optimized for design

2021 ◽  
Vol 249 ◽  
pp. 113310
Author(s):  
Philipp Schmidt ◽  
Michel Pleim ◽  
Jan Bielak ◽  
Josef Hegger
Keyword(s):  
Punching Shear ◽  
Shear Reinforcement ◽  
Activation Model ◽  
Flat Slabs ◽  
Column Bases

Punching shear behavior of reinforced concrete flat slabs with a varying amount of shear reinforcement

2019 ◽  
Vol 21 (1) ◽  
pp. 235-246 ◽  
Author(s):  
Philipp Schmidt ◽  
Dominik Kueres ◽  
Josef Hegger
Keyword(s):  
Reinforced Concrete ◽  
Shear Behavior ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Flat Slabs

Enhanced reliability assessment of punching shear resistance models for flat slabs without shear reinforcement

2021 ◽  
Vol 226 ◽  
pp. 111319
Author(s):  
Marcus Ricker ◽  
Tânia Feiri ◽  
Konstantin Nille-Hauf ◽  
Viviane Adam ◽  
Josef Hegger
Keyword(s):  
Reliability Assessment ◽  
Shear Resistance ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Flat Slabs

A Method to Predict the Punching Shear Strength of Flat Slabs with Shear Reinforcement Using a Strut-and-Tie Model

2017 ◽  
Vol 738 ◽  
pp. 25-35
Author(s):  
Lukáš Lyčka ◽  
Petr Štěpánek
Keyword(s):  
Shear Failure ◽  
Complex Problem ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Model Code ◽  
Strut And Tie ◽  
Flat Slabs ◽  
Model Code 2010 ◽  
Strut And Tie Model ◽  
Critical Aspects

The use of flat slabs in constructions due to its many functional and economic advantages is wide-spread. Behavior of flat slabs in shear and flexure is a fairly complex problem. Therefore, the punching shear failure belongs to one of the most critical aspects in the design of concrete buildings.The purpose of this paper is to describe a framework of the proposed method for predicting the punching shear of flat slabs with shear reinforcement. Most of the current codes in force are mainly based on empirical formulation. The proposed method is based on a strut-and-tie model and therefore could be considered as an analytical approach. For the purpose of demonstrating the effectiveness of the proposed method, the method is compared with some of the main methods currently in use, such as Eurocode EC2, ACI 318 and Model Code 2010. The comparison consists of results of more than 90 experiments on flat slabs with shear reinforcement, gathered from publications from all around the world.

Punching Shear in Post-Tensioned Flat Slabs with Shear Reinforcement: Codes and Tests

2016 ◽  
Vol 113 (2) ◽  
Author(s):  
Alessandra L. Carvalho ◽  
Guilherme S. Melo ◽  
Ronaldo B. Gomes
Keyword(s):  
Punching Shear ◽  
Shear Reinforcement ◽  
Flat Slabs ◽  
Post Tensioned

Strut-and-Tie Model for Predicting the Punching Shear of Flat Slabs with Shear Reinforcement

2017 ◽  
Vol 259 ◽  
pp. 178-183
Author(s):  
Lukáš Lyčka ◽  
Petr Štěpánek
Keyword(s):  
Physical Models ◽  
Punching Shear ◽  
Empirical Equations ◽  
Shear Reinforcement ◽  
Model Code ◽  
Strut And Tie ◽  
Flat Slabs ◽  
The World ◽  
Model Code 2010 ◽  
Strut And Tie Model

The purpose of this paper is to describe a framework of the proposed method for predicting the punching shear of flat slabs with shear reinforcement. The proposed method is based on a strut-and-tie model. Current methods of predicting the punching shear strength of flat slabs could be divided into these categories: models based on empirical equations, physical models, analytical methods and finite element methods. Most of the current codes in force would be best described as empirical formulations. Physical model for prediction of punching shear is described in Model Code 2010. Proposed method for flat slabs with shear reinforcement is based mainly on a strut-and-tie model and therefore could be considered as an analytical method.For the purpose of demonstrating the effectiveness of the proposed method, the method is compared with some of the main methods currently in use, such as Eurocode EC2, American code ACI 318 and Model Code 2010. The comparison consists of results of more than 98 experiments of punching shear on the flat slabs with shear reinforcement, gathered from publications from all around the world.

scholarly journals Investigation of the effects of opening size and location on punching shear resistance of flat slabs using Abaqus

2021 ◽  
Vol 15 (4) ◽  
pp. 136-147
Author(s):  
Nguyen Tuan Trung ◽  
Pham Thanh Tung
Keyword(s):  
Experimental Data ◽  
Numerical Model ◽  
Numerical Study ◽  
Shear Resistance ◽  
Design Principles ◽  
Numerical Results ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Flat Slabs ◽  
Abaqus Model

The paper presents a numerical study on the effects of opening size and location on punching shear resistance of flat slabs without drop panels and shear reinforcement using ABAQUS. The study proposes an ABAQUS model that is enable to predict the punching shear resistance of flat slabs with openings. The model is validated well with the experimental data in literature. Using the validated numerical model, the effects of opening size and location on the punching shear resistance of flat slabs are then investigated, and the numerical results are compared with those predicted by ACI 318-19 and TCVN 5574:2018. The comparison between experimental and numerical results shows that the ABAQUS model is reliable. The punching shear resistances calculated by ACI 318-19 and TCVN 5574:2018 with different opening sizes and locations are agreed well to each other, since the design principles between two codes now are similar.

scholarly journals PERILAKU PUNCHING SHEAR PADA HUBUNGAN KOLOM BULAT DENGAN FLAT SLAB AKIBAT BEBAN TEKAN AKSIAL

2019 ◽  
Vol 1 (1) ◽  
pp. 1-14
Author(s):  
Muhammad Zardi
Keyword(s):  
Concrete Strength ◽  
Load Condition ◽  
Maximum Load ◽  
Shear Capacity ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Eccentric Load ◽  
Flat Slab ◽  
Circular Column ◽  
Flat Slabs

The aim of the tests was to investigate the influence of concrete strength, the eccentricity of the column and the use of shear reinforcement in flat slabs on punching shear. The research specimens are 8 units of flat slabs. Flat slab size 1400 x 1400 mm2 with thickness of 120 mm. Flat slabs were connected with circular column with dimension 225 mm  of diameter and 200 mm of height. Flat slabs were made in to 2 variations of concrete strength, e.i. 30 MPa and 60 MPa, 2 variations of shear reinforcement, e.i. without shear reinforcement and with shear reinforcement and 2 variations of eccentricity that, e.i. without eccentricity and with eccentricity. Each treatment has 1 specimen. Each specimen has 6 cylinder specimens. Cylinder specimens used as a concrete strength control for main specimen (flat slab). The tests showed that the concrete strength had a strong influence on punching shear strength. This is shown by capacity increase of 42.78%; 54.00%; 46.59% and 0.02%. The value is ratio between the maximum load of the specimens with 60 MPa and 30 MPa at the same eccentricity and the same shear reinforcement. The eccentricity of column reduce the capacity of punching shear. This is shown by 3 specimens decrease in capacity of 3.70%; 36.75% and 7.30%. Only 1 specimen that increase in capacity of 9.27%. The value is ratio between the maximum load of the specimens with 40 mm eccentricity and 0 mm eccentricity at the same compressive strenght and the same shear reinforcement. The use of shear reinforcement does not always increase the punching shear capacity. There are 2 observations that increased capacity (52.07% and 65.37% at the centric load) and 2 observations decreased capacity (0.12% and 4.92% at the eccentric load). The value is ratio between the maximum load on the specimens using shear reinforcement with the specimens that do not use shear reinforcement at the same compressive strenght and the same eccentricity.The use of shear reinforcement increase punching shear capacity of flat slab at the centric load condition. The use of shear reinforcement decrease punching shear capacity of flat slab at the eccentric load condition.

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.

scholarly journals Theoretical prediction of punching shear capacity of flat slabs without shear reinforcement strengthened by concrete topping

2021 ◽  
Vol 1203 (2) ◽  
pp. 022108
Author(s):  
Daniel Čereš ◽  
Katarína Gajdošová
Keyword(s):  
Shear Resistance ◽  
Design Guidelines ◽  
Shear Capacity ◽  
Reinforcement Ratio ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Model Code ◽  
Flat Slabs ◽  
Eurocode 2 ◽  
Model Code 2010

Abstract The main reasons for strengthening flat slabs are the change of the use of a building, increase in the value of loads, degradation of the concrete cover layer, or insufficient reinforcement. This paper is focused on the assessment of punching shear capacity of the strengthened flat slabs without shear reinforcement. One of the possibilities how to enhance punching shear capacity is the addition of reinforced concrete topping. The main goal of this paper is to compare the possibilities for calculation of the increase in the punching shear capacity by investigation of the influence of different thicknesses of concrete toppings and different reinforcement ratio. A reference specimen is represented by a fragment of a flat slab with the thickness of h = 200 mm supported by circular column with the diameter of 250 mm. Three different thicknesses (50 mm, 100 mm, 150 mm) of concrete toppings were considered together with three different reinforcement ratios for each thickness of concrete overlay. Theoretical predictions of the punching shear resistance of flat slabs were evaluated by design guidelines according to the relevant standards: Eurocode 2 (EN 1992-1-1), Model Code 2010 and draft of the second generation of Eurocode 2 (prEN 1992-1-1). The differences in the influence of reinforcement ratio are significant. In Model Code 2010 the reinforcement ratio in concrete topping was considered in equation of moment of resistance. This is unlike in both of the mentioned Eurocodes, where the reinforcement ratio was assumed as a geometric average value of the original reinforcement ratio in the slab before strengthening and of the reinforcement ratio of concrete topping. All the predicted theoretical calculations are based on the perfect connection and bond between the original and new layer of concrete. These predictions should be verified by experimental investigation, which is going to be prepared shortly. By the additional increase in the thickness of concrete topping or in the amount of added reinforcement the attention should be payed to the limitation of the punching shear resistance by the value of the maximum punching shear resistance in the compression concrete strut.

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