scholarly journals Punching Shear Strength Characteristics of Flat Plate Panels Reinforced with Shearhead Collars: Experimental Investigation

2019 ◽  
Vol 5 (3) ◽  
pp. 528 ◽  
Author(s):  
Maroua Mohammed Majeed ◽  
Aamer Najim Abbas
Keyword(s):  
Experimental Investigation ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Flat Plate ◽  
Energy Absorption ◽  
Concrete Slab ◽  
Shear Capacity ◽  
Load Test ◽  
Punching Shear ◽  
Reference Specimen

This paper presents an experimental investigation on the punching shear strength of reinforced concrete flat plate slabs with shearhead collars. Eight reinforced concrete slab specimens were casted and tested under static load test, the load was applied at the center of slab by 100x100 mm steel column. The effect of the shapes, diameter and number of stiffeners has been discovered for shearheads through studying its effect on the load-deflection behavior, ultimate capacity, cracking load, failure mode, stiffness, ductility and energy absorption of tested specimens. The experimental results indicates that using square shearhead had achieved a slight increase in punching shear strength about 3% over that circular shearhead using the same surface area. Also, utilize 550 mm shearhead diameter will contribute to increase the punching shear strength about 14.5%. The increase in the number of stiffeners in specimen (CS4) had reduced the ultimate punching shear capacity by 20.3% over reference specimen. The first crack was decreased from 12.5kN to 7.5kN, when increases the number of stiffeners from one to two. The cracking load was increased with the increase of the diameter of circular shearhead from 10kN to 15Kn in specimens of 336mm and 550mm respectively. The specimen with 336mm diameter and 30mm height circular shearhead achieved 427 kN.m energy absorption, it is higher than the energy absorption of reference specimen by 2.6%. Also, using two stiffeners improved the energy absorption by 110.2% higher than the specimen with one stiffener.

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

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.

scholarly journals Strengthening of Reinforced Concrete Slab-Column Connections with Carbon Fiber Reinforced Polymer Laminates

2019 ◽  
Vol 10 (1) ◽  
pp. 265 ◽  
Author(s):  
Cheng-Chih Chen ◽  
Shun-Long Chen
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Concrete Slab ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Carbon Fiber Reinforced Polymer ◽  
Cfrp Laminates ◽  
Reinforced Polymer

This study presents the structural behavior and punching shear strength of the concrete slab-column connections strengthened with carbon fiber reinforced polymer (CFRP) laminates. The variables considered for the twelve specimens included the compressive strength of the concrete, the ratio of the tensile steel reinforcement, and the amount of the CFRP laminates. Square concrete slabs were simply supported along four edges. During the test, monotonically concentrated load was applied to the stub column located at the center of the slab. The punching shear strength, stiffness, and mode of failure were investigated. Test results demonstrated that increasing the compressive strength of concrete, ratio of the steel reinforcement, and amount of the CFRP laminates led to an increase in the punching shear strength of the slabs. Moreover, the CFRP laminates were effective in appreciably increasing the punching shear strength of the slab-column connections. An analytical approach was conducted to calculate the punching shear strength of the slab-column connections strengthened with CFRP laminates. Based on the theory of reinforced concrete members, the application of the CFRP laminates increased the flexural strength of the slab and resulted in an increase of the effective depth of the slab section. Consequently, the punching shear strength was increased. The results of the analytical calculation revealed that the analytical work accurately predicted the experimental punching shear strength.

scholarly journals Evaluation of punching shear strength of flat slabs supported on rectangular columns

2018 ◽  
Vol 33 ◽  
pp. 02007 ◽  
Author(s):  
Valery Filatov
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Structural Parameters ◽  
Experimental Studies ◽  
Punching Shear ◽  
Design Solution ◽  
Concrete Slabs ◽  
Reinforced Concrete Slabs ◽  
Rectangular Columns

The article presents the methodology and results of an analytical study of structural parameters influence on the value of punching force for the joint of columns and flat reinforced concrete slab. This design solution is typical for monolithic reinforced concrete girderless frames, which have a wide application in the construction of high-rise buildings. As the results of earlier studies show the punching shear strength of slabs at rectangular columns can be lower than at square columns with a similar length of the control perimeter. The influence of two structural parameters on the punching strength of the plate is investigated - the ratio of the side of the column cross-section to the effective depth of slab C/d and the ratio of the sides of the rectangular column Cmax/Cmin. According to the results of the study, graphs of reduction the control perimeter depending on the structural parameters are presented for columns square and rectangular cross-sections. Comparison of results obtained by proposed approach and MC2010 simplified method are shown, that proposed approach gives a more conservative estimate of the influence of the structural parameters. A significant influence of the considered structural parameters on punching shear strength of reinforced concrete slabs is confirmed by the results of experimental studies. The results of the study confirm the necessity of taking into account the considered structural parameters when calculating the punching shear strength of flat reinforced concrete slabs and further development of code design methods.

Effective Critical Section Evaluation of a Reinforced Concrete Flat-Plate Slab with Openings for its Punching Shear Strength Estimation

2015 ◽  
Vol 764-765 ◽  
pp. 1164-1169
Author(s):  
Dae Jin Kim ◽  
Jong Hwan Park ◽  
Tae Hun Ha
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Flat Plate ◽  
Numerical Algorithm ◽  
Critical Section ◽  
Direct Application ◽  
Punching Shear ◽  
Design Codes ◽  
Critical Sections ◽  
Section Evaluation

Most of current concrete design codes require that critical sections should be reduced in the presence of openings near columns to consider their effects on the punching shear strength of reinforced concrete flat-plate slabs. For example, ACI 318-11 stipulates that a part of the perimeter enclosed by two projection lines from the centroid of the column to the boundaries of the openings shall be considered ineffective. However, the direct application of this rule to practical cases may be rather complicated depending on the geometrical layout and shape of columns and openings. In this paper, simple mathematical formulations are proposed to evaluate the ineffective part of critical sections due to openings. This approach can be applied to the design of reinforced concrete flat-plate slabs based on ACI 318-11. A numerical algorithm is also developed to handle general cases where the ineffective parts of multiple openings overlap with each other.

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 Punching shear strength of corroded reinforced concrete slab-column connections

2021 ◽  
pp. 103489
Author(s):  
Kai Qian ◽  
Jin-Song Li ◽  
Ting Huang ◽  
Yun-Hao Weng ◽  
Xiao-Fang Deng
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Concrete Slab ◽  
Punching Shear ◽  
Reinforced Concrete Slab

Structural Effect of Using Steel Fiber Reinforcement on the Punching Shear of Self-Compacting Fiber Reinforced Concrete (SCFRC) Ribbed Slabs

2019 ◽  
Vol 972 ◽  
pp. 99-104
Author(s):  
Nurulain Hanida Mohamad Fodzi ◽  
M.H. Mohd Hisbany
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Slab ◽  
Fiber Reinforcement ◽  
Field Application ◽  
Fiber Reinforced Concrete ◽  
Punching Shear ◽  
Reinforced Concrete Slab ◽  
Reinforced Concrete Slabs

—Ribbed slab is an ideal structure for architects and contractors. It has an attractive soffit appearance and also giving economical value when it is come in weight and material saving. Placing and finishing of concrete slab normally influence about 30% - 35% of overall cost of flooring system. Ribbed slab or also known as one-way joist slab system consist of regularly spaced concrete joist or ribs spanning in one direction, a reinforced concrete slab cast integrally with the ribs and beam span between the columns, perpendicular to the ribs. However the complexity of the structure itself has become an issue due to honeycomb and poor workmanship. To overcome this problem, the use of Self-Compacting Steel Fiber Reinforcement Concrete (SCFRC) could improve the workmanship quality and to minimize the occurrence of honeycomb in concrete. Steel fiber in concrete improved the resistance of reinforced structural members cracking, deflection and other serviceability condition. Thus, this alternative approach will be the main focus in this study.Punching shear strength in reinforced concrete slabs subjected to concentrated loads has received a lot of emphasis due to its importance in the structural system, this failure may take place due to in conservative design of slab overloading and deterioration of strength in concrete and reinforcement. The continuous improvement of the technology of SCFRC and the better knowledge on the mechanical behavior of this SCFRC ribbed slab are contributing to a larger field application of SCFRC. Determination of punching shear strength has received considerable attention by the engineering profession in recent years.

Load Distribution and Shear Strength Evaluation of an Old Concrete T-Beam Bridge

2000 ◽  
Vol 1696 (1) ◽  
pp. 52-62 ◽  
Author(s):  
Riadh Al-Mahaidi ◽  
Geoff Taplin ◽  
Armando Giufre
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Load Distribution ◽  
Monitoring Program ◽  
Shear Capacity ◽  
Load Test ◽  
Load Rating ◽  
Element Analysis ◽  
Beam Bridge ◽  
T Beam

There are about 330 T-beam bridges in the Australian state of Victoria that were built before 1950. Australia-wide there are nearly 1,000 of these early T-beam bridges. The shear capacity of these bridges, when assessed in accordance with current codes of practice, is in some cases not adequate for the current design loading. In 1996, VicRoads, the Victorian state road authority, initiated a project to enable a more accurate assessment of the shear capacity of these bridges to be made so that decisions on load rating or replacement could be made. An analysis of an existing reinforced concrete T-beam bridge that had been identified for a load test to failure was commissioned. The purpose of the analysis was to predict the load distribution behavior and the ultimate strength and to advise on the testing and monitoring program. After successful load testing of the bridge, a comprehensive analysis of the observed behavior was carried out and compared with the theoretical models. The pre-and posttesting analysis, which was undertaken with linear and nonlinear finite element analysis and with the modified compression field theory, are described and the analysis results are compared with the real behavior of the tested bridge. In particular, the load distribution in the elastic range and the ultimate shear strength of the reinforced concrete T-beams are discussed. The consequences of these findings on the load rating procedures are discussed, and a strategy for rating old reinforced concrete T-beam bridges is outlined.

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