Study of Flat Slabs Strengthening against Punching Shear

2016 ◽  
Vol 249 ◽  
pp. 221-226 ◽  
Author(s):  
Jan Nováček ◽  
Miloš Zich
Keyword(s):  
Shear Crack ◽  
3D Models ◽  
Shear Resistance ◽  
Material Nonlinearity ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Design Code ◽  
Shear Strengthening ◽  
Absolute Value ◽  
Flat Slabs

The paper focuses on punching shear strengthening of flat slabs. In the study, different, in practice commonly used systems of strengthening are introduced, systems used less frequently are also mentioned. Chosen methods of strengthening are modeled using FEM software considering material nonlinearity and crack development in structures. 3D models with brick finite elements and discrete modeling of reinforcement are used. The way of modeling of the structure itself is verified against known results of tests of concrete slabs under punching shear. Comparison of individual systems of strengthening is performed from the viewpoint of absolute value of punching shear resistance and it is supplemented by calculation of punching shear resistance according to design code EC 1992. Simultaneously, results are compared to the approach of Critical Shear Crack Theory that places great emphasis on deformation capacity of the slab itself, which can be easily determined from FEM models which allow for material nonlinearity.

Effect of Membrane Forces on Punching Shear Capacity of Flat Slabs

2021 ◽  
Vol 322 ◽  
pp. 136-141
Author(s):  
Aleksandar Vidaković ◽  
Lucia Majtánová ◽  
Jaroslav Halvonik
Keyword(s):  
Shear Crack ◽  
Three Dimensional ◽  
Structural Response ◽  
Experimental Tests ◽  
Shear Resistance ◽  
Shear Capacity ◽  
Punching Shear ◽  
Element Analysis ◽  
Flat Slabs ◽  
Non Linear

The paper presents the analysis of the membrane forces and moment redistribution effect on punching shear capacity of flat slabs on the area of the inner column. The previous experimental tests performed on the isolated slab specimens representing the slab-column connections are assessed by the method that uses the levels-of-approximation (LoA) approach, introduced in the fib Model Code 2010. LoA I to III are intended for design and the highest LoA IV, which uses non-linear finite element analysis (NLFEA) combined with the Critical Shear Crack Theory (CSCT) model is used for assessment and a better understanding of the punching shear phenomenon. Both, multi-layered (2D) shell and three-dimensional (3D) continuum elements were used to model the slab-column connection specimen and were found to accurately predict the structural response. The numerical model was then used to conduct a parametric study on the influence of slab continuity on punching shear resistance. The results from a non-linear analysis of continuous slab models are then compared with the punching shear resistance obtained from the code provisions. The paper will present the obtained results by the LoA method and recommendations concerning of NLFEA modelling of RC flat slabs.

PREDICTION OF PUNCHING SHEAR RESISTANCE OF PRESTRESSED CONCRETE FLAT SLABS

2011 ◽  
Vol 14 (1) ◽  
pp. 180-196
Author(s):  
A M Elshihy ◽  
H A ShehabEldeen ◽  
O Shaalan ◽  
R S Mahmoud
Keyword(s):  
Prestressed Concrete ◽  
Shear Resistance ◽  
Punching Shear ◽  
Flat Slabs

Critical shear crack theory-based punching shear model for FRP-reinforced concrete slabs

2020 ◽  
pp. 136943322097814
Author(s):  
Xing-lang Fan ◽  
Sheng-jie Gu ◽  
Xi Wu ◽  
Jia-fei Jiang
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Shear Crack ◽  
Concrete Strength ◽  
Weight Ratio ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Crack Theory ◽  
Reinforced Concrete Slabs ◽  
Rc Slabs

Owing to their high strength-to-weight ratio, superior corrosion resistance, and convenience in manufacture, fiber-reinforced polymer (FRP) bars can be used as a good alternative to steel bars to solve the durability issue in reinforced concrete (RC) structures, especially for seawater sea-sand concrete. In this paper, a theoretical model for predicting the punching shear strength of FRP-RC slabs is developed. In this model, the punching shear strength is determined by the intersection of capacity and demanding curve of FRP-RC slabs. The capacity curve is employed based on critical shear crack theory, while the demand curve is derived with the help of a simplified tri-linear moment-curvature relationship. After the validity of the proposed model is verified with experimental data collected from the literature, the effects of concrete strength, loading area, FRP reinforcement ratio, and effective depth of concrete slabs are evaluated quantitatively.

Moment and shear transfer between columns and concrete slabs

1990 ◽  
Vol 17 (4) ◽  
pp. 621-628
Author(s):  
Amin Ghali ◽  
Adel A. Elgabry
Keyword(s):  
Shear Strength ◽  
Structural Design ◽  
American Concrete Institute ◽  
Punching Shear ◽  
Vertical Shear ◽  
Concrete Slabs ◽  
Finite Element Analyses ◽  
Shear Transfer ◽  
Flat Slabs ◽  
Punching Failure

Gravity and horizontal forces cause the transfer of vertical shear and moments between concrete flat slabs and their supporting columns. These forces can cause punching failure. Design equations for safety against punching given in the Canadian Standards Association and the American Concrete Institute codes are critically reviewed. It is shown that the equations give in some cases incorrect stresses which do not satisfy equilibrium. A modification is suggested which makes the equations applicable to all cases. The paper also discusses the codes' approach of sharing the resistance to transferred moment between resistances by flexure and by eccentricity of shear, using the coefficient γv. Comparisons are made with the result of finite element analyses. It is concluded that the code equations, with the suggested modification, are adequate, provided that appropriate values are used for the coefficient γv. Key words: columns, connections, flat concrete plates, moments, punching shear, reinforced concrete, shear strength, slabs, structural design.

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

Punching Shear Strengthening of Two-Way Flat Slabs with CFRP Grids

2014 ◽  
Vol 18 (2) ◽  
pp. 04013047 ◽  
Author(s):  
M. Hasan Meisami ◽  
Davood Mostofinejad ◽  
Hikaru Nakamura
Keyword(s):  
Punching Shear ◽  
Shear Strengthening ◽  
Flat Slabs

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.

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