scholarly journals Experimental and numerical studies on punching shear strength of concrete slabs containing sintered fly ash aggregates

2021 ◽  
Vol 20 (1) ◽  
pp. 15-25
Author(s):  
Ranjith Babu B. ◽  
◽  
Thenmozhi R ◽  
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Fly Ash ◽  
Constitutive Modelling ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Rc Slabs ◽  
Plate Connection ◽  
Ash Aggregates

This paper presents experimental and numerical investigations on M30 Grade of concrete containing 40% of sintered fly ash aggregates (SFAs) on the punching behaviour of reinforced concrete (RC) slabs. Two 1000 x 1000 x 100 mm reinforced concrete slabs were cast and subjected to punching tests. The experimental results were compared with creating a nonlinear finite element programme using ABAQUS. This 3D Finite element analyses were performed with the appropriate modelling of element size and the constitutive modelling of concrete. The material parameters of the damaged plasticity model in ABAQUS were calibrated based on the test results of slab – plate connection. The comparison between experimental and numerical results indicates that the calibrated model correctly predicts the punching shear response of the slabs. A modification of 0.4 is introduced in MC2010 code.

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.

scholarly journals Punching Shear Behavior of Reinforced Concrete Slabs under Fire using Finite Elements

2020 ◽  
Vol 26 (5) ◽  
pp. 106-127
Author(s):  
Athraa H. Gharbi ◽  
Akram S. Mahmoud
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Shear Failure ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Mechanical And Thermal Properties ◽  
Element Analysis ◽  
Reinforced Concrete Slabs ◽  
Fire Condition ◽  
Increasing Temperature

The main aim of this paper is studied the punching shear and behavior of reinforced concrete slabs exposed to fires, the possibility of punching shear failure occurred as a result of the fires and their inability to withstand the loads. Simulation by finite element analysis is made to predict the type of failure, distribution temperature through the thickness of the slabs, deformation and punching strength. Nonlinear finite element transient thermal-structural analysis at fire conditions are analyzed by ANSYS package. The validity of the modeling is performed for the mechanical and thermal properties of materials from earlier works from literature to decrease the uncertainties in data used in the analysis. A parametric study was adopted in this study,  it has many factors such as the ratios of length to thickness, fire temperature, time exposed to fire, concrete compressive strength, area exposed to fires and type of support. It can be concluded from this research the significant factors that affect the punching shear strength. However, the increasing ratio of length to thickness may be lead to increasing the deflection more than 123% at fire condition. Also, the increasing temperature leads to increasing the deflection about 40% at fire condition.

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.

Data Base for Punching Shear Strength of Reinforced Concrete Slabs and Evaluation for CCES Equation

2011 ◽  
Vol 90-93 ◽  
pp. 933-939 ◽  
Author(s):  
Qiu Ning Yang ◽  
Ming Jie Mao ◽  
Sumio Hamada
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Reinforced Concrete Slab ◽  
Factors Affecting ◽  
Reinforced Concrete Slabs ◽  
Numerous Test ◽  
Rc Slabs

Several equations for punching shear strength of the reinforced concrete slab have been proposed in the world. These equations have their own factors affecting the strength. There are numerous test data for punching shear strength of RC slabs, which have been obtained by numerous researchers. A database with approximately 300 specimens has been structured through the present study. In the present study seven equations for punching shear strength are evaluated based on the database. CCES equation is also evaluated from the present database.

scholarly journals Nonlinear finite element analysis of punching shear strength of reinforced concrete slabs supported on L-shaped columns

2020 ◽  
Vol 19 (4) ◽  
pp. 125-138
Author(s):  
Qing Zhang ◽  
Graeme J. Milligan ◽  
Maria Anna Polak
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Nonlinear Finite Element ◽  
Punching Shear ◽  
Shear Behaviour ◽  
Concrete Slabs ◽  
Shear Stresses ◽  
Element Analysis ◽  
Reinforced Concrete Slabs

Most current concrete design codes include provisions for punching shear of reinforced concrete slabs supported on columns with L, T, and cruciform shapes. Reference studies verifying the accuracy of these code provisions are typically not provided. Empirical data of punching failures of slabs supported on columns with L, T, and cruciform shapes are limited due to the cost and time required to test specimens with slab thicknesses and column sizes commonly used in practice. In this paper, the punching shear behaviour of five interior L-shaped slab-column connections, one without a slab opening and four with slab openings, subjected to static concentric loading are analyzed using a plasticity-based nonlinear finite element model (FEM) in ABAQUS. The FEM is similar to models previously calibrated at the University of Waterloo and are calibrated considering nine slabs that are tested to study the impact of column rectangularity on the punching shear behaviour of reinforced concrete slabs. The finite element analysis results indicate that shear stresses primarily concentrate around the ends of the L, and that current code predictions from ACI 318-19 and Eurocode 2 may be unconservative due to the assumed critical perimeters around L-shaped columns.

scholarly journals Finite Element Simulation on Punching Shear Behavior of Reinforced Concrete Slabs

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
A. K. M. Jahangir Alam ◽  
Khan Mahmud Amanat
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Finite Element Simulation ◽  
Shear Behavior ◽  
Crack Pattern ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Element Simulation

A finite element simulation for experimental punching shear behavior of reinforced concrete slab is presented in this paper. The numerical simulation is based on previously tested 15 reinforced concrete model slabs. Finite element analysis of reinforced concrete slabs subjected to punching load is evaluated and results are compared with experiments. This study involves development of a nonlinear strategy which implements solution for a realistic description of the deflection, load carrying capacity and crack, pattern related to punching shear of RC slabs for several types of slab thickness, edge restraints, and reinforcement ratio. It has been shown that the load versus. deflection diagram and ultimate load capacity obtained from FE analysis closely match with the experimental results. Comparison of crack pattern of the slab also shows good agreement. It has been shown that using appropriate method and material for numerical simulation, significant benefit can be achieved using finite element tools and advanced computing facilities in obtaining safe and optimum solutions without doing expensive and time-consuming laboratory tests.

scholarly journals Deformations of R.C.Circular Slabs in Fire Condition

2018 ◽  
Vol 4 (4) ◽  
pp. 712 ◽  
Author(s):  
Abdelraouf Tawfik Kassem
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Slenderness Ratio ◽  
High Surface ◽  
High Surface Area ◽  
Concrete Slabs ◽  
Finite Element Models ◽  
Reinforced Concrete Slabs ◽  
Fire Condition ◽  
In Fire

Reinforced concrete slabs are elements in direct contact with superimposed loads, having high surface area and small thickness. Such a condition makes slabs highly vulnerable to fire conditions. Fire results in exaggerated deformations in reinforced concrete slabs, as a result of material deterioration and thermal induced stresses. The main objective of this paper is to deeply investigate how circular R.C. slabs, of different configurations, behave in fire condition. That objective has been achieved through finite element modelling. Thermal-structural finite element models have been prepared, using "Ansys". Finite element models used solid elements to model both thermal and structural slab behaviour. Structural loads had been applied, representing slab operational loads, then thermal loads were applied in accordance with ISO 843 fire curve. Outputs in the form of deflection profile and edge rotation have been extracted out of the models to present slab deformations. A parametric study has been conducted to figure out the significance of various parameters such as; slab depth, slenderness ratio, load ratio, and opening size; regarding slab deformations. It was found that deformational behaviour differs significantly for slabs of thickness equal or below 100 mm, than slabs of thickness equal or above 200 mm. On the other hand considerable changes in slabs behaviour take place after 30 minutes of fire exposure for slabs of thickness equals or below 100 mm, while such changes delay till 60 minutes for slabs of thickness equals or above 200 mm.

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