scholarly journals Punching shear in reinforced concrete flat slabs with hole adjacent to the column and moment transfer

2014 ◽  
Vol 7 (3) ◽  
pp. 414-467 ◽  
Author(s):  
D. C. Oliveira ◽  
R. B. Gomes ◽  
G. S. Melo
Keyword(s):  
Reinforced Concrete ◽  
Reinforcement Rate ◽  
Load Test ◽  
Punching Shear ◽  
Test Results ◽  
Flat Slab ◽  
Flat Slabs ◽  
Flexural Reinforcement ◽  
Hole Dimension ◽  
The Moment

The structural behavior and the ultimate punching shear resistance of internal reinforced concrete flat slab-column connections, with one hole adjacent to the column, with or without flexural moment transfer of the slab to the column was investigated. Main variables were: the existence whether or not hole, flexural reinforcement layout and ratio, the direction and sense of the moment transferred and the eccentricity of the load (M (moment transferred to column) / V (shear)) ratio at the connection - 0,50 m or 0,25 m. Seven internal slab-column joining were tested and ultimate loads, cracking, deflections, concrete and reinforcement strains were analyzed. The existence of hole adjacent to the smaller column dimension, the hole dimension, flexural reinforcement rate and placing, the variation of relation Mu/Vu in function of the load, and, than, of eccentricity of the load, influenced the slabs behavior and rupture load. Test results were compared with the estimations from CEB-FIP/MC1990 [7], EC2/2004 [12], ACI-318:2011 [1] and NBR 6118:2007 [5]. ACI [1] and EC2 [12] presented most conservative estimates, although have presented some non conservative estimates. Brazilian NBR [5], even though being partly based in EC2 [12], presented smaller conservative estimates and more non conservative estimates. A modification on all codes is proposed for taking in account the moment caused by the eccentricity at the critical perimeter for slabs with holes.

scholarly journals Experimental verification of punching shear resistance of flat slab fragments

2021 ◽  
Vol 30 (4) ◽  
Author(s):  
Simona Šarvaicová ◽  
Viktor Borzovič
Keyword(s):  
Reinforced Concrete ◽  
Experimental Verification ◽  
Shear Resistance ◽  
Linear Analysis ◽  
Punching Shear ◽  
Test Results ◽  
Loading Test ◽  
Design Models ◽  
Flat Slab ◽  
Standard Design

The paper deals with the loading test results of an experimental reinforced concrete flat slab fragment, which was supported by an elongated rectangular column. The slab specimens were 200 mm thick and were designed without any shear reinforcement. By experimentally obtained punching shear resistance, the accuracy of the standard design models for prediction punching resistance was compared. The results of the experiments were also compared with the results of a numerical non-linear analysis performed in the Atena program.

scholarly journals A Comparative Study of Flat Slabs Using Different Shear Reinforcement Parameters

2018 ◽  
Vol 7 (2.20) ◽  
pp. 321
Author(s):  
N Girish ◽  
N Lingeshwaran
Keyword(s):  
Reinforced Concrete ◽  
Brittle Failure ◽  
Shear Failure ◽  
Crack Pattern ◽  
Steel Plates ◽  
Punching Shear ◽  
Shear Reinforcement ◽  
Flat Slab ◽  
Flat Slabs ◽  
Four Corners

Punching shear failure is a brittle failure and it is one of the most important types of failure to be considered while designing a reinforced concrete flat slab. This paper aims to study the performance of reinforced concrete flat slabs equipped with different punching shear reinforcement parameters. Three flat slab specimens were cast where two specimens contain punching shear reinforcement in the form of shear stirrups and structural shearbands. The test specimens have length and width of 1000mm and thickness of 185mm for the slabs. The slabs are connected to a column at the center with length and breadth of 300mm and a depth of 700mm. The test specimens were supported by steel plates with length and breadth of 150mm and a thickness of 25mm at the four corners of the slab. The test specimens are loaded on the column face at the top. The deflection, strain and crack pattern were observed and recorded.   

scholarly journals Performance of Shear Reinforcement against Punching Shear Loads

2019 ◽  
Vol 9 (2) ◽  
pp. 841-850
Keyword(s):  
Numerical Study ◽  
Shear Capacity ◽  
Punching Shear ◽  
Slab Thickness ◽  
Test Results ◽  
Shear Reinforcement ◽  
Concentrated Load ◽  
Flat Slab ◽  
Flat Slabs ◽  
Strength Formula

This research targets to maximize the ductility and strength of the reinforced concrete flat slabs. However, to be efficient, the shear reinforcement must be anchored well in the tension and compression zones of the slab. The test results on the slab-column connection models which provided with shear reinforcement are introduced in this study. The benefits of using shear reinforcement are to reduce the slab thickness, and to minimize both the cost and the total weight of the structure. Twelve flat slab specimens have been tested to study the effect of different types of steel RFT on the punching shear of the flat slab. The experimental parameters include no shear reinforcement which study the advantage of using tension RFT ONLY against punching shear, no shear reinforcement which study the advantage of using compression RFT against punching shear, shear RFT (Vertical Stirrups) which study the effect of using shear RFT with constant distribution 0.5d, and a new distribution of shear stirrups which study the effect of using new different width & spacing of vertical stirrups. The twelve specimens were loaded with concentrated load at the mid span until failure. The general behavior of the deformation of the tested slab specimens was examined and recorded (cracking, deflection, and strain in both steel and concrete). A comparison established between the experimental and the numericaltheoretical results obtained from applying the punching shear strength formula given in design codes, and finite element modeling analysis; ABAQUS 2017 software package was used for this analysis. A total of six building codes were examined with regard to their provisions concerning the punching shear. A comparison had been made between the research test results and the codes equations to improve the methods of the analysis about the flat slabs. This study aimed to improve the punching shear capacity of flat slab which leads to more accurate results compared with the codes predictions. To achieve this aim, an experimental and numerical study was carried out for this investigation.

Reinforced concrete slab-column edge connections with shear studs

2000 ◽  
Vol 27 (2) ◽  
pp. 338-348 ◽  
Author(s):  
Ehab F El-Salakawy ◽  
Maria Anna Polak ◽  
Monir H Soliman
Keyword(s):  
Reinforced Concrete ◽  
Large Scale ◽  
Concrete Slab ◽  
Punching Shear ◽  
Test Results ◽  
Shear Reinforcement ◽  
Reinforced Concrete Slab ◽  
Test Parameters ◽  
Flexural Reinforcement ◽  
Large Scale Tests

The paper reports the results of an experimental investigation on the influence of shear studs on the behaviour of reinforced concrete slab-column edge connections with openings. The test parameters were the location of openings around the column, the size of openings, and the existence of shear reinforcement. The objective of the paper is to present and discuss the results of large-scale tests on slabs with shear stud reinforcement and compare these test results with those of tests on identical slabs but without shear reinforcement. All tested slabs contained same amounts of typical flexural reinforcement (ACI 318-95 and CSA A23.3-94). The presented test results can be used for studying the behaviour of slab-column connections and for calibration of the predictive models.Key words: reinforced concrete, edge connections, flat concrete plates, punching shear, shear strength, openings, failure, shear studs, shear reinforcement.

scholarly journals Punching Shear Strength of Reinforced Concrete Flat Plates with GFRP Vertical Grids

2021 ◽  
Vol 11 (6) ◽  
pp. 2736
Author(s):  
Min Sook Kim ◽  
Young Hak Lee
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Test Results ◽  
Shear Reinforcement ◽  
Flat Plates ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Vertical Grids

In this study, the structural behavior of reinforced concrete flat plates shear reinforced with vertical grids made of a glass fiber reinforced polymer (GFRP) was experimentally evaluated. To examine the shear strength, experiments were performed on nine concrete slabs with different amounts and spacings of shear reinforcement. The test results indicated that the shear strength increased as the amount of shear reinforcement increased and as the spacing of the shear reinforcement decreased. The GFRP shear reinforcement changed the cracks and failure mode of the specimens from a brittle punching to flexure one. In addition, the experimental results are compared with a shear strength equation provided by different concrete design codes. This comparison demonstrates that all of the equations underestimate the shear strength of reinforced concrete flat plates shear reinforced with GFRP vertical grids. The shear strength of the equation by BS 8110 is able to calculate the punching shear strength reasonably for a concrete flat plate shear reinforced with GFRP vertical grids.

Punching Shear Behavior of Flat Slabs Utilizing Reactive Powder Concrete with and without Flexural Reinforcement

2021 ◽  
Vol 26 (1) ◽  
pp. 04020060
Author(s):  
Mohammed M. Kadhum ◽  
Salah M. Harbi ◽  
Shahad S. Khamees ◽  
Mustafa S. Abdulraheem ◽  
Ehsan Noroozinejad Farsangi
Keyword(s):  
Shear Behavior ◽  
Punching Shear ◽  
Reactive Powder Concrete ◽  
Flat Slabs ◽  
Flexural Reinforcement ◽  
Reactive Powder

scholarly journals A Novel Feature Selection Approach Based on Tree Models for Evaluating the Punching Shear Capacity of Steel Fiber-Reinforced Concrete Flat Slabs

Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3902 ◽  
Author(s):  
Shasha Lu ◽  
Mohammadreza Koopialipoor ◽  
Panagiotis G. Asteris ◽  
Maziyar Bahri ◽  
Danial Jahed Armaghani
Keyword(s):  
Feature Selection ◽  
Reinforced Concrete ◽  
Predictive Models ◽  
Steel Fiber ◽  
Shear Capacity ◽  
Fiber Reinforced Concrete ◽  
Punching Shear ◽  
Fiber Reinforced ◽  
Steel Fiber Reinforced Concrete ◽  
Flat Slabs

When designing flat slabs made of steel fiber-reinforced concrete (SFRC), it is very important to predict their punching shear capacity accurately. The use of machine learning seems to be a great way to improve the accuracy of empirical equations currently used in this field. Accordingly, this study utilized tree predictive models (i.e., random forest (RF), random tree (RT), and classification and regression trees (CART)) as well as a novel feature selection (FS) technique to introduce a new model capable of estimating the punching shear capacity of the SFRC flat slabs. Furthermore, to automatically create the structure of the predictive models, the current study employed a sequential algorithm of the FS model. In order to perform the training stage for the proposed models, a dataset consisting of 140 samples with six influential components (i.e., the depth of the slab, the effective depth of the slab, the length of the column, the compressive strength of the concrete, the reinforcement ratio, and the fiber volume) were collected from the relevant literature. Afterward, the sequential FS models were trained and verified using the above-mentioned database. To evaluate the accuracy of the proposed models for both testing and training datasets, various statistical indices, including the coefficient of determination (R2) and root mean square error (RMSE), were utilized. The results obtained from the experiments indicated that the FS-RT model outperformed FS-RF and FS-CART models in terms of prediction accuracy. The range of R2 and RMSE values were obtained as 0.9476–0.9831 and 14.4965–24.9310, respectively; in this regard, the FS-RT hybrid technique demonstrated the best performance. It was concluded that the three hybrid techniques proposed in this paper, i.e., FS-RT, FS-RF, and FS-CART, could be applied to predicting SFRC flat slabs.

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