The Performance of Self-Compacted High Strength Concrete Columns with Laced Steel Section

In view of the great orientation to the steel buildings and the large role played by the columns in carrying and transferring the loads it is necessary to go to strengthen the steel rolled columns to meet the requirements of the architecture that witch is looking for large spacing. In present paper this research the objectives of this research can be summarized as following: prevent local buckling occurs in columns, strengthen the steel columns from the weak axis in a new methodology, to compare buckling loads of single lacing reinforcement versus double lacing reinforcement and obtain a high bearing column steel section with small surface area increase in column strength capacity. Different parameters are taking into account to investigate the behavior and strength of steel and composite columns such as slenderness ratio, and double lacings and presence of longitudinal reinforcement that parallel to the column height. The type of concrete that adopt is self-compact concrete with high compressive strength. The new and alternative method is were used to strengthen the steel rolled columns at low cost by strengthening the weak axis to preventing or minimize buckling of the columns by using high strength concrete self-compacted without main reinforcements with steel section columns reinforced by lacing as single and double so that it work as full composite structural element and there are connections between concrete block and steel column. There are five specimens with the same height of 1450 mm that was classified as the control specimen and the others with different parameters such as lacing configurations, presence of longitudinal dowels and presence of concrete subject to concentric load. All specimens except the control filled with self-compacted high strength concrete. The result showed that as increase in strength in presence of concrete as compared with the control specimen. Control specimen gave strength capacity compared with the others composite specimens; the increased are 50% composite column, 62.50% composite column with single lacing and 75.00% composite column with double lacing respectively. Specimen (CL1CDL2R) increased in strength capacity as compared with the control specimen 87.50% and 7.14% compared with specimen (CL1CDL) because of presence dowels along the specimen height that increase the stiffness of the composite column. Presence of single and double lacing reduced the buckling value because of reduced the effective columns height. Specimen (CC1L1) gave maximum buckling 32.00 mm compared with the others specimens such as CL1C), (CL1CSL), (CL1CDL) and (CL1CDL2R) respectively, there is significant difference in buckling that reduced by 17.19%, 28.13%, 45.31% and 55.63% respectively.

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Simulation Model for Ultra-High Strength Concrete Filled Composite Column under Static Loads

Proceedings of the 10th International Conference on Advances in Steel Concrete Composite and Hybrid Structures ◽

10.3850/978-981-07-2615-7_r015 ◽

2012 ◽

Author(s):

T. Y. Song ◽

J. Y. Richard Liew

Keyword(s):

Simulation Model ◽

High Strength Concrete ◽

High Strength ◽

Static Loads ◽

Composite Column ◽

Strength Concrete ◽

Filled Composite

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Evaluation of Bond Strength between Steel Fiber Reinforced Ultra-High Strength Concrete and Rebar

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.665.41 ◽

2015 ◽

Vol 665 ◽

pp. 41-44

Author(s):

B.I. Bae ◽

Hyun Ki Choi ◽

Chang Sik Choi

Keyword(s):

Bond Strength ◽

High Strength Concrete ◽

Steel Fiber ◽

High Strength ◽

Fiber Reinforced ◽

Strength Concrete ◽

Pull Out ◽

Reinforced Concrete Member ◽

Significant Difference ◽

Cover Thickness

In order to design reinforced concrete member using steel fiber ultra high strength concrete, current structural design methods should be re-evaluated because it has significant difference in material characteristics compared with normal concrete. In this study, bond strength of steel fiber reinforced ultra-high strength concrete was evaluated. For this purpose, direct pull out test specimens were constructed with variables of cover thickness, compressive strength of matrix and fiber inclusion ratio. According to the test, bond strength were sensitively varied with cover thickness and fiber inclusion. Because bond strength was determined by tensile strength of concrete. Comparing test results with theoretical methods suggested by Tepfers, specimens without steel fiber show good agreement with analytical method, because this method were based on elasticity. And other empirical equations were evaluated with other previous researches.

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Experimental research on the fire performance of a special cross-shaped composite column with a high-strength concrete-filled steel tubular core

Advances in Structural Engineering ◽

10.1177/1369433217753426 ◽

2018 ◽

Vol 21 (11) ◽

pp. 1608-1619 ◽

Cited By ~ 1

Author(s):

Yong Yang ◽

Lin Zhang ◽

Yicong Xue ◽

Dengpan Zhao ◽

Hui Deng ◽

...

Keyword(s):

Experimental Research ◽

High Strength Concrete ◽

High Strength ◽

Fire Performance ◽

Composite Column ◽

Strength Concrete

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Behaviour of Composite Column of Cold-Formed Steel Section without Web Stiffener Integrated with Ferrocement Jacket

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.752-753.528 ◽

2015 ◽

Vol 752-753 ◽

pp. 528-532

Author(s):

Anis Saggaff ◽

Khaled Alenezi ◽

Mahmood Md Tahir ◽

Talal Alhajri ◽

Mohamad Ragae

Keyword(s):

Axial Load ◽

Load Capacity ◽

Axial Loading ◽

Column Height ◽

Composite Column ◽

Compression Load ◽

Composite Columns ◽

Strength Capacity ◽

Cold Formed Steel ◽

Steel Section

Cold-formed steel (CFS) is known to be a thin section. Thus it is considered a weak slender steel section which limits the compression capacity of the column. The aim of this study was to determine the ultimate capacity of built-up lipped CFS (assembled with ferrocement jacket) as composite column (CFFCC) under axial compression load. Nine specimens of composite columns were prepared and tested. The main parameters that varied in the CFFCC columns were column height, cold-formed steel thickness, and influence of ferrocement jacket. There were 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 by a thick steel plate. The results indicated that ferrocement jacket provided sufficient lateral support to the column web and significantly increased both the strength and ductility of the specimens under axial loading. The strength capacity of CFFCC improved significantly, about 149% greater than that of bare steel column section. It was also found that the axial load capacity of CFS-ferrocement jacket composite columns (CFFCC) had increased significantly (in the range of 20% to 40%) as thickness of CFS increased.

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Experimental behaviour of very high-strength concrete-encased steel composite column subjected to axial compression and end moment

Proceedings 12th international conference on Advances in Steel-Concrete Composite Structures - ASCCS 2018 ◽

10.4995/asccs2018.2018.7034 ◽

2018 ◽

Cited By ~ 2

Author(s):

Zhenyu Huang ◽

Xinxiong Huang ◽

Weiwen Li ◽

Yingwu Zhou ◽

Lili Sui ◽

...

Keyword(s):

High Strength Concrete ◽

High Strength ◽

Compression Tests ◽

Plastic Design ◽

Composite Column ◽

Composite Columns ◽

Strength Concrete ◽

Steel Composite ◽

Compressive Resistance ◽

Very High

A type of cost-effective and very high strength concrete (VHSC) with 28-day compressive strength of 100-150 MPa is developed for applications in concrete-encased steel composite column constructions. This paper experimentally investigates the structural behaviour of VHSC encased steel composite columns based on a series of pure compression and eccentric compression tests. It is found that such high-strength composite column exhibits brittle post peak behaviour and low ductility but with acceptable compressive resistance. Throughout the tests, the main failure of VHSC encased column under compressive load is brittle spalling of concrete followed by local buckling of the reinforcement bars. The splitting and slippage may occur between concrete and steel section due to bending downward action. The confinement effect by the shear stirrups designed based on normal reinforced concrete codes may not be sufficient. Composite column subjected to initial flexural cracking due to end moment load with large eccentricity may experience degradation in the stiffness and ultimate resistance so that plastic design resistance may not be achieved. Analytical studies show that the N-M interaction model based on current design codes may over-predict the combined resistance of the composite columns. Therefore, a modified elastic-plastic design approach based on strain compatibility is developed to evaluate the compressive resistance of concrete encased composite columns. The validation against the test data shows a reasonable and conservative estimation on the combined resistance of VHSC encased composite columns.

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