Behaviour of masonry infilled steel frames

1989 ◽  
Vol 16 (6) ◽  
pp. 865-876 ◽  
Author(s):  
J. L. Dawe ◽  
C. K. Seah
Keyword(s):  
Key Words ◽  
Ultimate Strength ◽  
Large Scale ◽  
Steel Frames ◽  
Shear Capacity ◽  
Test Series ◽  
Interface Conditions ◽  
Initial Stiffness ◽  
Roof Level ◽  
Major Crack

Masonry shear panels used as infilling in steel frames are investigated experimentally. Twenty-eight large-scale specimens were tested to ultimate panel strength under in-plane, horizontal loading applied at roof level. Of the parameters varied in the test series, interface conditions between panel edges and frame were found to significantly affect the strength and behaviour. Column-to-panel ties were found to be ineffective in increasing ultimate strength while initial stiffness was only marginally increased. A 20 mm gap between the upper edge of a panel and roof beam was particularly detrimental to the system shear capacity. While panel openings reduced initial major crack load, the same was not necessarily true for their effect on ultimate strength. Reinforced bond beams at one third and two thirds of the panel height forced initial major cracking to occur quite close to ultimate, which itself was only marginally increased. The lowest initial major cracking and ultimate loads were recorded for those specimens consisting of a panel in a hinge frame with a 20 mm gap between the upper edge of the panel and roof beam. Key words: masonry, infilled panel, steel frame, experimental, in-plane, behaviour, strength.

scholarly journals Experimental/Numerical Evaluation of Steel Trapezoidal Corrugated Infill Panels with an Opening

2021 ◽  
Vol 11 (7) ◽  
pp. 3275
Author(s):  
Majid Yaseri Gilvaee ◽  
Massood Mofid
Keyword(s):  
Energy Dissipation ◽  
Ultimate Strength ◽  
Steel Plate ◽  
Shear Walls ◽  
Experimental Results ◽  
Structural Performance ◽  
Initial Stiffness ◽  
Infill Panels ◽  
Energy Dissipation Capacity ◽  
Ductility Ratio

This paper investigates the influence of an opening in the infill steel plate on the behavior of steel trapezoidal corrugated infill panels. Two specimens of steel trapezoidal corrugated shear walls were constructed and tested under cyclic loading. One specimen had a single rectangular opening, while the other one had two rectangular openings. In addition, the percentage of opening in both specimens was 18%. The initial stiffness, ultimate strength, ductility ratio and energy dissipation capacity of the two tested specimens are compared to a specimen without opening. The experimental results indicate that the existence of an opening has the greatest effect on the initial stiffness of the corrugated steel infill panels. In addition, the experimental results reveal that the structural performance of the specimen with two openings is improved in some areas compared to the specimen with one opening. To that end, the energy dissipation capacity of the specimen with two openings is obtained larger than the specimen with one opening. Furthermore, a number of numerical analyses were performed. The numerical results show that with increasing the thickness of the infill plate or using stiffeners around the opening, the ultimate strength of a corrugated steel infill panel with an opening can be equal to or even more than the ultimate strength of that panel without an opening.

scholarly journals Experimental Investigation into the Seismic Performance of Prefabricated Reinforced Masonry Shear Walls with Vertical Joint Connections

2021 ◽  
Vol 11 (10) ◽  
pp. 4421
Author(s):  
Zhiming Zhang ◽  
Fenglai Wang
Keyword(s):  
Seismic Performance ◽  
Cross Sections ◽  
Shear Walls ◽  
Construction Method ◽  
Shear Capacity ◽  
Initial Stiffness ◽  
Equivalent Viscous Damping ◽  
Displacement Ductility ◽  
Reinforced Masonry ◽  
Cracking Performance

In this study, four single-story reinforced masonry shear walls (RMSWs) (two prefabricated and two cast-in-place) under reversed cyclic loading were tested to evaluate their seismic performance. The aim of the study was to evaluate the shear behavior of RMSWs with flanges at the wall ends as well as the effect of construction method. The test results showed that all specimens had a similar failure mode with diagonal cracking. However, the crack distribution was strongly influenced by the construction method. The lateral capacity of the prefabricated walls was 12% and 27% higher than that of the corresponding cast-in-place walls with respect to the rectangular and T-shaped cross sections. The prefabricated walls showed better post-cracking performance than did the cast-in-place wall. The secant stiffness of all the walls decreased rapidly to approximately 63% of the initial stiffness when the first major diagonal crack was observed. The idealized equivalent elastic-plastic system showed that the prefabricated walls had a greater displacement ductility of 3.2–4.8 than that of the cast-in-place walls with a displacement ductility value of 2.3–2.7. This proved that the vertical joints in prefabricated RMSWs enhanced the seismic performance of walls in shear capacity and ductility. In addition, the equivalent viscous damping of the specimens ranged from 0.13 to 0.26 for prefabricated and cast-in-place walls, respectively.

Effect of Detailed Formations on the In-Plane Shear Capacity of Hairpin Connectors in Precast RC Floor Slabs

2010 ◽  
Vol 163-167 ◽  
pp. 1510-1514 ◽  
Author(s):  
Rui Pang ◽  
Shu Ting Liang ◽  
Xiao Jun Zhu ◽  
Yao Meng
Keyword(s):  
Simulation Analysis ◽  
Plate Thickness ◽  
Shear Capacity ◽  
Steel Plates ◽  
Strong Impact ◽  
Deformation Capacity ◽  
Initial Stiffness ◽  
Plane Shear ◽  
Floor Slabs ◽  
Strength And Deformation

Detailed formation of precast floor slab connectors has significant effect on their shear capacity, but there is no such specific provision on it at present. The effects of detailed formations on the shear strength, stiffness and deformation capacity of hairpin connectors(HPC) were studied, through numerical simulation analysis under in-plane shear force. The imbedded depth (d), slug length (h), steel plate thickness (t) and its stickout(s) were taken as parameters. The analysis results show that: ⅰ) the increase of imbedded depth can improve the bearing capacity and stiffness of HPC, but decrease the deformation capacity; ⅱ) with the increase of slug length, the HPC strength, stiffness and deformation capacity raised a lot; ⅲ) the steel plates’ thickness has small effect on the stiffness, but has strong impact on the strength and deformation capacity of HPC. ⅳ) the stickout can affect the initial stiffness and yield strength of HPC slightly, but has a considerable impact on its ultimate strength and deformation capacity. On the basis of analysis, recommendations on formation details of HPC are proposed for design and construction.

Durability of coral-reef-sand concrete beams reinforced with basalt fibre-reinforced polymer bars in seawater

2021 ◽  
pp. 136943322098166
Author(s):  
Wang Xin ◽  
Shi Jianzhe ◽  
Ding Lining ◽  
Jin Yundong ◽  
Wu Zhishen
Keyword(s):  
Coral Reef ◽  
Marine Environment ◽  
Failure Modes ◽  
Concrete Beams ◽  
Shear Capacity ◽  
Initial Stiffness ◽  
Basalt Fibre ◽  
Rc Structures ◽  
Reinforced Polymer ◽  
Fibre Reinforced Polymer

A combination of coral reef sand (CRS) concrete and fibre-reinforced polymer (FRP) bars provides an effective solution to the durability deficiency in conventional RC structures. This study experimentally investigates the durability of CRS concrete beams reinforced with basalt FRP (BFRP) bars in a simulated marine environment. Flexural tests are conducted on a total of fourteen CRS concrete beams aged in a cyclic wet-dry saline solution at temperatures of 25, 40 and 55°C. The variables comprise the types of reinforcement (steel and BFRP), the aging duration and the temperature. The failure modes, capacities, deflections and crack development of the beams are analysed and discussed. The results indicate that the ultimate load of the beams exhibits no degradation after aging, whereas the failure mode of the BFRP-CRS concrete beams transition from flexure to shear, which is caused by the degradation in the mechanical properties of the stirrups. The aged BFRP-CRS concrete beams show a substantial increase of over 70% in their initial stiffness compared with the control beams (beams without aging) and a substantial decrease in their crack width after aging due to the prolonged maturation of the concrete. Furthermore, a formula for calculating the shear capacity in the existing code is modified by a partial factor equal to 2, which can predict the capacity of a CRS concrete beam reinforced with BFRP bars in a marine environment.

scholarly journals An Experimental Study of Horizontal Bearing Capacity of Vertical Steel Floral Tube Micropiles with Double Grouting

2018 ◽  
Vol 2018 ◽  
pp. 1-11
Author(s):  
Kaiyang Wang ◽  
Yanjun Shang
Keyword(s):  
Bearing Capacity ◽  
Large Scale ◽  
Slip Surface ◽  
Bending Moment ◽  
Shear Capacity ◽  
Soil Reinforcement ◽  
Scale Model ◽  
Soil Pressure ◽  
Floral Tube ◽  
Grouting Pressure

This paper examines the performance of a novel technology, vertical steel floral tube micropiles with double grouting. It is the combination of micropile technology and double grouting technology. A large-scale model tank was applied to impart horizontal bearing capacity, and the slope soil pressure and flexural performance of the micropile were investigated under four experimental conditions. The peak grouting pressure during the double grouting process was defined as the fracturing pressure of the double grouting, and it was positively correlated to the interval time between first grouting and secondary grouting. Compared with traditional grouting, double grouting increased the horizontal bearing capacity of the single micropile with the vertical steel floral tube by 24.42%. The horizontal bearing capacity was also 20.25% higher for the structure with three micropiles, compared with a 3-fold value of horizontal sliding resistance. In the test, the maximum bending moment acting on the pile above the sliding surface was located 2.0–2.5 m away from the pile top, and the largest negative bending moment acting on the pile below the slip surface was located 4.0 m away from the pile top. The ultimate bending moment of the single pile increased by 12.8 kN·m with double grouting, and the bending resistance increased by 96.2%. The experimental results showed that the double grouting technology significantly improved the horizontal bearing capacity of the micropile with the steel floral tube, and the soil reinforcement performance between piles was more pronounced. Also, the shear capacity and the flexural capacity were significantly improved compared with the original technology.

scholarly journals Studi Eksperimental: Perilaku Siklik Anticompression Split-K Braced Steel Frame

2020 ◽  
Vol 14 (2) ◽  
pp. 143-153
Author(s):  
Oksa Eberly ◽  
◽  
Sri Murni Dewi ◽  
Wisnumurti Wisnumurti ◽  
◽  
...  
Keyword(s):  
Steel Frames ◽  
Cyclic Strength ◽  
Steel Frame ◽  
Lateral Loads ◽  
Cyclic Tests ◽  
Initial Stiffness ◽  
Loading Tests ◽  
Quasistatic Loading ◽  
Cyclic Loading Tests ◽  
Good Behaviour

This paper presents an experimental study on the behaviour of a braced steel frame with a proposed system: anticompression brace system (ABS) subjected to cyclic lateral loads. The ABS is proposed to deal with common brace buckling problems. In the study, split-K braced steel frames: with ABS and with ordinary brace system (OBS) were used as speciments. Cyclic loading tests were conducted to evaluate the performance of the proposed system in preventing the brace to buckle and to obtain the behaviour of the frame with ABS compared to the frame with OBS under cyclic quasistatic loading. From the cyclic tests, it was observed that the proposed system worked in preventing the braces to buckle, hence, the aimed state, “buckling prevention” was achieved. The results of the study also show that the frame with ABS had a lower initial stiffness compared to the frame with OBS, nevertheless, after exceeding drift ratio of 0.85% based on raw data or 0.64% based on fitted-curves, the frame with ABS exhibited good behaviour through lower degradations in stiffness and cyclic strength relative to the frame with OBS that experienced sudden and greater degradations.

scholarly journals Antimicrobial activity of Moringa oleifera: A short review

2020 ◽  
Vol 12 (1) ◽  
pp. 128-132
Author(s):  
I.A. Raubilu ◽  
U. Isah ◽  
M.A. Ahmad
Keyword(s):  
Antimicrobial Activity ◽  
Middle East ◽  
Key Words ◽  
Large Scale ◽  
Moringa Oleifera ◽  
Short Review ◽  
Medicinal Properties ◽  
Pathogenic Microbes ◽  
Potential Use ◽  
Moringa Oleifera Lam

Moringa oleifera Lam. (Family Moringaceae) is well – known for its various medicinal properties. It grows wild in the tropical and subtropical areas of Asia, Africa and the Middle East. In Nigeria, Moringa oleifera trees are planted at a large scale especially in the northern part of the country. It has been widely used in the treatment of certain diseases as a traditional medicinal herb. Antimicrobial activity is the most studied property of Moringa oleifera. Many studies have shown that nearly all types of Moringa oleifera tissues exhibit antimicrobial activity including antibacterial, antifungal, antiviral and anti parasitic property. This review describes progress on research conducted to understand the antimicrobial activity of Moringa oleifera and discusses the potential use of Moringa oleifera in the control of pathogenic microbes. Key words: Antimicrobial activity; Moringa oleifera; pathogenic microbes, control.  

scholarly journals An Opportunities-Based Approach to Mitigating Risks Associated with Infrastructure Development Projects

2009 ◽  
Vol 3 ◽  
pp. 9-15 ◽  
Author(s):  
Don Messerschmidt
Keyword(s):  
Risk Factors ◽  
South Asia ◽  
Key Words ◽  
Large Scale ◽  
Field Experience ◽  
Development Projects ◽  
Infrastructure Development ◽  
Negative Consequences ◽  
Infrastructure Projects ◽  
Energy And Environment

‘Risk' is a major point of focus in the literature on resettlement and reconstruction associated with the impacts of major infrastructure development on project affected individuals and families. Previous approaches to risk appear to emphasize the negative consequences of development, and it is no wonder then that project affected people often emphatically resist development and change. This paper proposes that a more pro-active, positive opportunities and benefits approach be taken in dealing with resettlement and reconstruction associated with large scale infrastructure projects. The discussion is focused on the eight ‘risk factors' (or ‘opportunity factors'?) listed in the well known ‘Impoverishment Risk and Reconstruction' (IRR) Model. Three more such factors are added to the list based on field experience in South Asia. The point is that by emphasizing the potential opportunities and benefits, project affected people are more likely to be supportive of projects that may disrupt their lives. Key words: Resettlement, opportunities, risk, IRR model, South Asia, infrastructure development  doi: 10.3126/hn.v3i0.1912 Hydro Nepal: Journal of Water, Energy and Environment Issue No. 3, January, 2008 Page 9-15

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