Experimental and Numerical Investigations of Composite Concrete–Steel Plate Shear Walls Subjected to Axial Load

This research is presented experimental and numerical investigations of composite concrete-steel plate shear walls under axial loads to predicate the effect of both concrete compressive strength and aspect ratio of the wall on the axial capacity, lateral displacement and axial shortening of the walls. The experimental program includes casting and testing two groups of walls with various aspect ratios. The first group with aspect ratio H/L=1.667 and the second group with aspect ratio H/L=2. Each group consists of three composite concrete -steel plate wall with three targets of cube compressive strength of values 39, 54.75 and 63.3 MPa. The tests result obtained that the increase in concrete compressive strength results in increasing the ultimate axial load capacity of the wall. Thus, the failure load, the corresponding lateral displacement and the axial shortening increased by increasing the compressive strength and the rate of increase in failure load of the tested walls was about (34.5% , 23.1%) as compressive strength increased from 39 to 63.3 MPa for case of composite wall with aspect ratio H/L=1.667 and H/L=2, respectively. The effect of increasing aspect ratio on the axial load capacity, lateral displacement and axial shortening of the walls was also studied in this study. Compared the main performance characteristic of the testing walls, it can be indicated that the walls with aspect ratio equal to (2) failed under lower axial loads as compared with walls with aspect ratio equal to 1.667 ratios by about (5.8, 12, 15.6 %) at compressive strength (39, 54.75, 63.3 MPa), respectively and experienced large flexural deformations. The mode of failure of all walls was characterized by buckling of steel plates as well as cracking and crushing of concrete in the most compressive zone. Nonlinear three-dimensional finite element analysis is also used to evaluate the performance of the composite wall, by using ABAQUS computer Program (version 6.13). Finite element results were compared with experimental results. The comparison shows good accuracy.

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EFFECT OF ASPECT RATIO ON THE BEHAVIOR OF GFRP-RC CIRCULAR COLUMNS UNDER SIMULATED SEISMIC LOADING

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.2021.8(1).str-47 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Amr Elsayed Mohammed Abdallah ◽

Ehab Fathy El-Salakawy

Keyword(s):

Aspect Ratio ◽

Axial Load ◽

Load Capacity ◽

Load Level ◽

Experimental Results ◽

Rc Columns ◽

Drift Capacity ◽

Glass Fiber Reinforced ◽

Axial Load Capacity ◽

Code Provisions

The mechanical and physical properties of glass fiber-reinforced polymer (GFRP) reinforcement are different from steel, which requires independent code provisions for GFRP-reinforced concrete (RC) members. The currently available code provisions for GFRP-RC members still need more research evidence to be inclusive. For example, the available provisions for confinement reinforcement of FRP-RC columns do not consider the effects of column aspect ratio, which is not yet supported by any available research data. In this study, two full-scale spirally reinforced GFRP-RC circular columns were constructed and tested under concurrent seismic and axial loads. Both specimens had an aspect ratio (shear span-to-diameter ratio) of 7.0, while other two specimens with an aspect ratio of 5.0, from a previous stage of this study, were included for comparison purposes. For each aspect ratio, each specimen was loaded under one of two levels of axial load; 20 or 30% of the axial load capacity of the column section. All test specimens had a 35 MPa concrete compressive strength, 350-mm diameter, 85-mm spiral pitch and 1.2% longitudinal reinforcement ratio. The experimental results were analyzed in terms of hysteretic response, drift capacity and inelastic deformability hinge length. Based on the experimental results, it can be concluded that the aspect ratio affects the magnitude of secondary moments and inelastic deformability hinge length. In addition, the aspect ratio may affect drift capacity of GFRP-RC columns, depending on axial load level.

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Behaviour of Composite Column of Cold-Formed Steel Section with Web-Stiffener Integrated with Ferrocement Jacket

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.752-753.533 ◽

2015 ◽

Vol 752-753 ◽

pp. 533-538

Author(s):

Khaled Alenezi ◽

Mahmood Md Tahir ◽

Talal Alhajri ◽

Mohamad Ragae

Keyword(s):

Compressive Strength ◽

Axial Load ◽

Load Capacity ◽

High Ratio ◽

Column Height ◽

Composite Column ◽

Composite Columns ◽

Axial Load Capacity ◽

Strength Capacity ◽

Cold Formed Steel

Cold-formed steel (CFS) is known as slender or class 4 section due to high ratio of web-to-thickness ratio. The compressive strength of this type of section is usually very low as it tends to fail due to distortion and warping before reaching the actual compressive strength. The aim of this study is to determine the ultimate capacity of build-up lipped CFS assembled with ferrocement jacket where web-stiffener is provided as the proposed composite column (CFFCC) is under axial compression load. Nine specimens of composite columns were prepared and tested. The main parameters varied in the CFFCC columns are column height, cold-formed steel thickness and influence of ferrocement jacket and web-stiffener. There are three different heights of the CFFCC composite column namely 2000mm, 3000mm and 4000mm used in this study. All CFFCC columns were tested under axial load where a thick steel plate is used to evenly distribute the applied load. The results show the effect of providing both the ferrocement jacket to increase the confinement effect and the web stiffener to provide sufficient lateral support to the column web. A significant increase in both the strength and the ductility of the specimens under axial loading has been recorded. The strength capacity of CFFCC has been improved by about 178% greater than that of bare steel column. Also it is found that, axial load capacity of CFS-ferrocement jacket composite columns (CFFCC) were increased with the increase in thickness of CFS. The use of web-stiffener has improved the axial load capacity of the column but not that significant.

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EXPERIMENTAL ASSESSMENT OF CONCENTRICALLY LOADED PRE-STRESSING CONCRETE-FILLED STEEL TUBULAR COLUMNS

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2015.165 ◽

2015 ◽

Vol 2 (1) ◽

Author(s):

Aman Mwafy ◽

Amr El-Dieb ◽

Abdulaziz Lazkani

Keyword(s):

Compressive Strength ◽

Axial Load ◽

Load Capacity ◽

Concrete Compressive Strength ◽

Tubular Columns ◽

Modes Of Failure ◽

Axial Load Capacity ◽

Load Tests ◽

Expansive Additive ◽

Cfst Columns

Although expansive additives are frequently used in contemporary concrete-filled steel tubular (CFST) structures to improve the bond between concrete and steel tubes, little information is available regarding their influence on the mechanical characteristics of CFST columns. This reflects the pressing need to investigate the impacts of the pre-stressing achieved through the expansive additives, especially on the concrete confinement and axial load capacity of CFST. This paper thus discusses the results of concentric load tests carried out for 12 pre-stressing CFST columns to assess their axial load capacity and modes of failure. The main parameters investigated are the concrete compressive strength (40, 50 and 90 MPa) and the dosage of the expansive agent (0%, 6%, 12% and 24% by mass of cement). The results indicate that the axial load capacity is improved by increasing both the concrete compressive strength and the expansive additive dosage. The expansive additive has an important influence on the confinement effect of CFST. The paper presents new test results that contribute to fill a gap in the literature and provides insights into the behavior of concentrically loaded pre-stressing CFST columns.

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Comparative study of Y-shaped and circular floating piles in consolidating clay

Canadian Geotechnical Journal ◽

10.1139/cgj-2015-0634 ◽

2016 ◽

Vol 53 (9) ◽

pp. 1483-1494 ◽

Cited By ~ 9

Author(s):

Yaru Lv ◽

Charles W.W. Ng ◽

Sze Yue Lam ◽

Hanlong Liu ◽

Xuanming Ding

Keyword(s):

Bearing Capacity ◽

Axial Load ◽

Load Capacity ◽

Limit State ◽

Three Dimensional ◽

Axial Loads ◽

Axial Load Capacity ◽

Lateral Extent ◽

Adjacent Soil ◽

Geometrical Effects

Although engineers often make use of pile geometry to improve the axial load capacity of piles, geometrical effects on floating piles in consolidating clay are still not fully understood. This paper reports two centrifuge model tests to investigate the responses of a Y-shaped pile and a circular pile subjected to an induced dragload and applied axial loads. Three-dimensional numerical back-analyses were performed considering the elastoplastic slip. The Y-shaped and circular piles developed similar downdrag, but the dragload induced on the Y-shaped pile was larger than that induced on the circular pile. As the axial load increased, the neutral plane shifted upward along a nonlinear path, of which the gradient of the Y-shaped pile was gentler. The ultimate bearing capacity of the Y-shaped pile was 1.73 times that of the circular pile. The dragload on the Y-shaped and circular piles was eventually eliminated at approximately 0.56 and 0.83 times the corresponding ultimate pile capacities, respectively. Three flanges of the Y-shaped pile “hung-up” adjacent soil that settled together with the pile shaft. The lateral extent of vertically nonuniform trapped soil decreased with increasing axial load. Even though the Y-shaped and circular piles encountered a similar serviceability limit state, Y-shaped pile had advantages in bearing capacity.

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Post-Fire Performance of Square Concrete-Filled Steel Tube Columns under Uni-Axial Load

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1016.618 ◽

2021 ◽

Vol 1016 ◽

pp. 618-623

Author(s):

Jaksada Thumrongvut ◽

Apichat Tipcharoen ◽

Kamonwan Prathumwong

Keyword(s):

Ambient Temperature ◽

Axial Load ◽

Elevated Temperatures ◽

Load Capacity ◽

Steel Tube ◽

Fire Performance ◽

Concrete Filled Steel Tube ◽

Axial Load Capacity ◽

Comparison Results ◽

Axial Shortening

This paper presents experimental studies on the post-fire performance of concrete-filled steel tube (CSFT) columns under uni-axial load. The structural responses and axial load capacity of CSFT columns after exposure to elevated temperatures are investigated and discussed. All of the specimens are 750 mm in height, the nominal cross-section of the specimen is 150 mm x 150 mm, and have cylinder compressive strength of 18 MPa. The primary test parameters to be measured during the uni-axial compression test are wall thicknesses of the square tube (3.0 mm, 4.5 mm and 6.0 mm) and three different exposure to elevated temperatures (400°C, 600°C and 800°C). The results showed that the load-axial shortening relationship of the CSFT columns have a linear elastic response up to 80-90% of axial load capacity. After the axial load capacity is reached, the load-axial shortening curves are rarely becoming a nonlinear manner. It is also shown that the axial load capacity and ductility of the post-fire test columns are decreased significantly compared to the columns at ambient temperature, depending mainly on the elevated temperature. In addition, by comparing the axial load capacity of the test results with those obtained from the ACI design equation, the comparison results indicate that calculation formula in ACI code unconservative predicts the axial load capacity of the CSFT columns after exposure to elevated temperatures. Finally, the residual strength ratios are modified to both strength of concrete and steel tube under ambient temperature, and analyzed to evaluate the effect of post-fire behavior on the axial capacity of CFST columns.

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