scholarly journals Experimental and Numerical Analysis of the Punching Shear Resistance Strengthening of Concrete Flat Plates by Steel Collars

2021 ◽  
Vol 11 (6) ◽  
pp. 7853-7860
Author(s):  
A. A. Abdulhussein ◽  
M. H. Al-Sherrawi
Keyword(s):  
Experimental Study ◽  
Numerical Analysis ◽  
Shear Resistance ◽  
Punching Shear ◽  
Control Specimen ◽  
Flat Plates ◽  
Concentrated Load ◽  
Steel Angles ◽  
Abaqus Software ◽  
Good Agreement

In this study, six square reinforced concrete flat plates with dimensions of (1500×1500×100) mm were tested under a concentrated load applied on a column located at the center of the slabs. One of these slabs was the control specimen, whereas, in the others, steel angles (steel collars) were used, fixed at the connection region between the slab and the column to investigate the effect of the presence of these collars on punching shear strength. Five thicknesses were used (4, 5, 6, 8, 10mm) with constant legs of angles (75×75) mm of the steel collars to investigate the effects on the punching shear resistance with respect to the control slab. The results of the experimental study show that the punching shear resistance increased by 41 to 77% when steel collars were used. The experimental results were in good agreement with the numerical analysis acquired with the ABAQUS software.

scholarly journals Punching shear resistance of UHPFRC

2019 ◽  
Author(s):  
Andreas Lampropoulos ◽  
James N. Duncan ◽  
Ourania T. Tsioulou
Keyword(s):  
High Performance ◽  
Shear Resistance ◽  
High Energy ◽  
Punching Shear ◽  
Concentrated Load ◽  
Steel Fibres ◽  
Tension And Compression ◽  
Shear Performance ◽  
High Energy Absorption ◽  
Normal Strength

<p>Ultra-High Performance Fibre Reinforced Concrete (UHPFRC) is a high performance cementitious material with enhanced strength in tension and compression and significantly high energy absorption in the post crack region. Its mix composition is not much dissimilar from that of normal strength concrete. The main difference is that only fine aggregates are used in order to enhance the homogeneity of the mix, while microsilica is used to improve the density of the mix thereby reducing voids and defects. A high percentage of steel fibres is used to increase the tensile strength and at the same time to provide ductility.</p><p>UHPFRC has been recently introduced in applications such as bridge decks, thin slabs and for the strengthening of existing elements. Even if there are various published studies on the compressive, tensile and flexural characteristics of UHPFRC, the punching shear performance of UHPFRC without additional steel bars has not been sufficiently studied. In this paper an extensive experimental work has been conducted on UHPFRC tiles with various thicknesses and various percentages of steel fibres and tests have been conducted under a concentrated load. Using the experimental results, the punching shear characteristics of the various UHPFRC mixes have been evaluated and shear resistance values have been proposed.</p>

Inducing Frictional Force to Enhance the Transient Response in Beams

2019 ◽  
Vol 22 (2) ◽  
pp. 88-93
Author(s):  
Hamed Khanger Mina ◽  
Waleed K. Al-Ashtrai
Keyword(s):  
Numerical Analysis ◽  
Transient Response ◽  
Frictional Force ◽  
Damping Ratio ◽  
Experimental Results ◽  
Damping Capacity ◽  
Tightening Force ◽  
Contact Areas ◽  
Good Agreement ◽  
Ansys Workbench

This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.

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

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.

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