Seismic retrofit of concrete slabs against punching shear: Testing and modelling

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.

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Estimating punching shear capacity of steel fibre reinforced concrete slabs using sequential piecewise multiple linear regression and artificial neural network

Measurement ◽

10.1016/j.measurement.2019.01.035 ◽

2019 ◽

Vol 137 ◽

pp. 58-70 ◽

Cited By ~ 12

Author(s):

Nhat-Duc Hoang

Keyword(s):

Neural Network ◽

Artificial Neural Network ◽

Linear Regression ◽

Steel Fibre ◽

Shear Capacity ◽

Punching Shear ◽

Concrete Slabs ◽

Fibre Reinforced Concrete ◽

Steel Fibre Reinforced Concrete ◽

Reinforced Concrete Slabs

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Moment and shear transfer between columns and concrete slabs

Canadian Journal of Civil Engineering ◽

10.1139/l90-070 ◽

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.

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Punching shear mechanism of reinforced concrete slabs with corroded reinforcing bars

Life-Cycle of Civil Engineering Systems - Life-Cycle of Structural Systems ◽

10.1201/b17618-186 ◽

2014 ◽

pp. 1257-1264

Author(s):

Y Tanaka ◽

T Sudoh

Keyword(s):

Reinforced Concrete ◽

Punching Shear ◽

Concrete Slabs ◽

Reinforcing Bars ◽

Shear Mechanism ◽

Reinforced Concrete Slabs

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Analysis on Punching Shear Behavior of the Raft Slab Reinforced with Steel Fibers

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.400-402.335 ◽

2008 ◽

Vol 400-402 ◽

pp. 335-340

Author(s):

Xiao Wei Wang ◽

Wen Ling Tian ◽

Zhi Yuan Huang ◽

Ming Jie Zhou ◽

Xiao Yan Zhao

Keyword(s):

Reinforced Concrete ◽

Concrete Slab ◽

Shear Behavior ◽

Shear Capacity ◽

Steel Fibers ◽

Punching Shear ◽

Concrete Slabs ◽

Mass Concrete ◽

Reinforced Concrete Slab ◽

The Common

The thickness of the raft slab is determined by punching shear. The raft slab is commonly thick, which causes concrete volume is large. Mass concrete can bring disadvantage to the foundation. In order to increase the bearing capacity and reduce the thickness, it is suggested that the raft slab to be reinforced by steel fibers. There are five groups of specimens in this paper. S1 is the common reinforced concrete slab. S2 and S3 are concrete slabs reinforced by steel fibers broadcasted layer by layer when casting specimen. S4 and S5 are concrete slabs reinforced by steel fibers mixed homogeneously when making concrete. The punching shear tests of these slabs were done. The test results indicate that the punching shear capacity of the slab reinforced with steel fibers is higher than that of concrete slab, the stiffness and crack resistance of the steel fibers reinforced concrete slab are better than those of the common concrete slab and the punching shear of the slabs with different construction methods of steel fibers is similar. It analyses the punching shear behavior of the slab reinforced with steel fibers and suggests the ultimate bearing formula. The calculative values are coincided with the measured values well.

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Strength and ductility of lightweight reinforced concrete slabs under punching shear

Structures ◽

10.1016/j.istruc.2020.08.002 ◽

2020 ◽

Vol 27 ◽

pp. 2329-2345 ◽

Cited By ~ 2

Author(s):

A. Deifalla

Keyword(s):

Reinforced Concrete ◽

Punching Shear ◽

Concrete Slabs ◽

Reinforced Concrete Slabs ◽

Strength And Ductility

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Modeling Punching Shear Capacity of Fiber-Reinforced Polymer Concrete Slabs: A Comparative Study of Instance-Based and Neural Network Learning

Applied Computational Intelligence and Soft Computing ◽

10.1155/2017/9897078 ◽

2017 ◽

Vol 2017 ◽

pp. 1-11 ◽

Cited By ~ 1

Author(s):

Nhat-Duc Hoang ◽

Duy-Thang Vu ◽

Xuan-Linh Tran ◽

Van-Duc Tran

Keyword(s):

Neural Network ◽

Regression Model ◽

Shear Capacity ◽

Fiber Reinforced Polymer ◽

Punching Shear ◽

Polymer Concrete ◽

Concrete Slabs ◽

Fiber Reinforced ◽

Reinforced Concrete Slabs ◽

Reinforced Polymer

This study investigates an adaptive-weighted instanced-based learning, for the prediction of the ultimate punching shear capacity (UPSC) of fiber-reinforced polymer- (FRP-) reinforced slabs. The concept of the new method is to employ the Differential Evolution to construct an adaptive instance-based regression model. The performance of the proposed model is compared to those of Artificial Neural Network (ANN) and traditional formula-based methods. A dataset which contains the testing results of FRP-reinforced concrete slabs has been collected to establish and verify new approach. This study shows that the investigated instance-based regression model is capable of delivering the prediction result which is far more accurate than traditional formulas and very competitive with the black-box approach of ANN. Furthermore, the proposed adaptive-weighted instanced-based learning provides a means for quantifying the relevancy of each factor used for the prediction of UPSC of FRP-reinforced slabs.

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