scholarly journals Shear Tests of Deep Hollow Core Slabs Strengthened by Core-Filling

2020 ◽  
Vol 10 (5) ◽  
pp. 1709
Author(s):  
Hyo-Eun Joo ◽  
Sun-Jin Han ◽  
Min-Kook Park ◽  
Kang Su Kim
Keyword(s):  
Shear Strength ◽  
Resistance Mechanism ◽  
Hollow Core ◽  
Shear Reinforcement ◽  
Shear Cracks ◽  
Shear Strengthening ◽  
Strain Behavior ◽  
Long Span ◽  
Current Design ◽  
The Web

Prestressed hollow core slabs (PHCSs) have commonly been applied to long-span structures, due to their excellent flexural capacity and deflection control performance. However, in quite a few cases, the web-shear strength at member ends subjected to high shear forces is insufficient, because the web of the PHCS is very thin, making it difficult to place shear reinforcement, and the prestress is not fully effective in transfer length regions. Accordingly, a variety of shear strengthening methods have been proposed to improve the web-shear strength of PHCS ends. In this study, experimental research was conducted to investigate the shear resistance mechanism of PHCS strengthened by core-filling method, which has been most widely used in the construction field. The number of filled cores and the shear reinforcement ratio were set as the main test variables, and the patterns and angles of shear cracks that occurred in the PHCS units and filled cores, respectively, and the strain behavior of the shear reinforcement, were measured and analyzed in detail. This study also analyzed the test results based on the current design codes, and proposed a modified shear strength equation that can be applied to the core-filled PHCS.

scholarly journals Shear Performance for Prestressed Concrete Hollow Core Slabs

2020 ◽  
Vol 10 (5) ◽  
pp. 1636 ◽  
Author(s):  
Yong-Jun Lee ◽  
Hyeong-Gook Kim ◽  
Min-Jun Kim ◽  
Dong-Hwan Kim ◽  
Kil-Hee Kim
Keyword(s):  
Compressive Strength ◽  
Shear Strength ◽  
Prestressed Concrete ◽  
Hollow Core ◽  
Loading Test ◽  
Cross Sectional ◽  
Simply Supported ◽  
Shear Performance ◽  
Compressive Strength Of Concrete ◽  
The Web

This study evaluated the shear performance of prestressed concrete hollow core slabs (HCS), which are convenient to use as floor structures of flexible spaces. A total of 18 specimens, with cross-sectional height and presence of topping concrete as variables, were fabricated by extrusion. A four-point loading test was conducted using simply supported beams. The results showed that shear performance satisfied the requirements of ACI 318-19 regardless of cross-sectional height or presence of topping concrete. Through comparison with past studies, the web-shear strength of HCS was found to be influenced by compressive stress due to prestress at the centroid, compressive strength of concrete, and shear span-to-depth ratio.

Experimental investigation of the web-shear strength of deep hollow-core units

PCI Journal ◽  
2011 ◽  
Vol 56 (4) ◽  
pp. 83-104 ◽  
Author(s):  
Keith D. Palmer ◽  
Arturo E. Schultz
Keyword(s):  
Experimental Investigation ◽  
Shear Strength ◽  
Hollow Core ◽  
The Web

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.

scholarly journals Impact of Reinforcement Ratio on Shear Behavior of I-Shaped UHPC Beams with and without Fiber Shear Reinforcement

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1525 ◽  
Author(s):  
Altug Yavas ◽  
Cumali Ogun Goker
Keyword(s):  
Shear Strength ◽  
Failure Mode ◽  
High Performance Concrete ◽  
Shear Behavior ◽  
Reinforcement Ratio ◽  
Steel Fibers ◽  
Experimental Program ◽  
Shear Reinforcement ◽  
Ultimate Shear Strength ◽  
Loading Test

In the presented paper, the impacts of steel fiber use and tensile reinforcement ratio on shear behavior of Ultra-High Performance Concrete (UHPC) beams were investigated from the point of different tensile reinforcement ratios. In the scope of the experimental program, a total of eight beams consisting of four reinforcement ratios representing low to high ratios ranged from 0.8% to 2.2% were casted without shear reinforcement and subjected to the four-point loading test. While half of the test beams included 30 mm end-hooked steel fibers (SF-UHPC) with 2.0 vol%, the remaining beams were produced without the fiber to show possible effectiveness of the fiber use. The shear performances were discussed in terms of the load—deflection response, cracking pattern and failure mode, first cracking load and ultimate shear strength. In this sense, all the non-fiber beams were failed by shear with a dramatic load drop, regardless of the tensile reinforcement amount, before the yielding of reinforcement and they produced no deflection capability. The test results showed that while the inclusion of steel fibers to the UHPC mixture with low reinforcement ratios changed the failure mode from the shear to flexure, it significantly enhanced the ultimate shear strength in the case of higher reinforcement ratio through the SF-UHPC’ superior mechanical properties and fibers’ crack-bridging ability.

scholarly journals Post-tensioned girders with low amounts of shear reinforcement: Shear strength and influence of flanges

2013 ◽  
Vol 56 ◽  
pp. 357-371 ◽  
Author(s):  
Michael Rupf ◽  
Miguel Fernández Ruiz ◽  
Aurelio Muttoni
Keyword(s):  
Shear Strength ◽  
Shear Reinforcement ◽  
Post Tensioned

scholarly journals Determination of reinforcing bars for tests of hollow core slabs with continuity

2013 ◽  
Vol 6 (6) ◽  
pp. 903-932
Author(s):  
A. P. Santos ◽  
M. A. Ferreira ◽  
R. C. Carvalho ◽  
L. M. Pinheiro
Keyword(s):  
Shear Strength ◽  
The Other ◽  
Hollow Core ◽  
Reinforcing Bars ◽  
Simply Supported ◽  
Resistance Moment ◽  
Hollow Core Slab ◽  
Maximum Shear Strength

The structural designs of floors formed by hollow core slabs usually consider these as simply-supported slabs. In recent years there have been project changes and hollow core slabs with continuity are widely used. The objective of this study is to suggest a way to calculate the reinforcement bars to be used in tests with continuity provided by a structural topping. Thus, this paper presents a method based on the maximum positive resistance moment and maximum shear strength of a hollow core slab. The method is applied to a test in hollow core slab specimens which have the following dimensions: 2 m width, 6 m long, and 21 cm high. The results indicated that the method was satisfactory to the performed test, and can therefore be applied to the other test configurations or even designs.

scholarly journals TECHNICAL CONDITION OF PRECAST BEAMS WITH THE USE OF EXPANDED LIGHTWEIGHT CONCRETE HOLLOW-CORE SLABS

2019 ◽  
pp. 35-42
Author(s):  
Г. Смоляго ◽  
G. Smolyago ◽  
С. Дрокин ◽  
S. Drokin ◽  
А. Дронов ◽  
...  
Keyword(s):  
Lightweight Concrete ◽  
Significant Proportion ◽  
Physical And Mechanical Properties ◽  
Technical Condition ◽  
Building Structures ◽  
Hollow Core ◽  
Shear Cracks ◽  
Total Load ◽  
Normative Documents ◽  
Methods Of Calculations

The use of expanded lightweight concrete for the production of building structures can significantly reduce the weight, which is important in the manufacture of hollow-core slabs; the weight is a significant proportion of the total load. In the current regulatory documents, the physical and mechanical properties of expanded lightweight concrete differ significantly, and sometimes contradict each other. The defects and damages of expanded lightweight concrete hollow-core slabs are described in the case of the kindergarten built near 50 years ago. They appeared during the manufacture of the slabs - uncompacted concrete and uncovered ribs, or in the course of exploitation of the building - normal cracking, holes for pipes and corrosion of reinforcement. Two slabs in emergency condition have numerous longitudinal and shear cracks and chips of concrete caused by overloading. The differences in normative documents and methods of calculations used at the time of designing the kindergarten building and at the present time are shown. The assessment of the technical condition of the expanded lightweight concrete hollow-core slabs considering defects and damages are carried out

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