Mechanical Properties of High Strength Concrete Filled Steel Tubular Columns

2012 ◽  
Vol 472-475 ◽  
pp. 1119-1125 ◽  
Author(s):  
Ke Feng Tan ◽  
Lai Bao Liu
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Strength Increase ◽  
Strength Concrete ◽  
Tubular Columns ◽  
Short Columns ◽  
Core Concrete

This study investigated the mechanical properties of High Strength Concrete filled steel tubular short columns (HSCFSTSC) with length to diameter ratio (L/D) of 3.5.The strength of concrete used to fill the steel tubular columns ranged from 54MPa to 116MPa. The test results showed that using a steel tube as confinement can significantly improve the ductility and compressive strength of core concrete. The magnitude of compressive strength increase of core concrete was directly proportional to the Confinement Index, , and the extent of improvement of the ductility increases as the  increases. For thoroughly improving the ductility of core concrete, the Confinement Index  should be equal or larger than 0.48. The formula used to calculate the load bearing capacity of HSCFSTSC was given out.

scholarly journals Effect of Locally Available Wheat Straw Ash in Developing High Strength Concrete

2021 ◽  
pp. 19-28
Author(s):  
Muhammad Armaghan Siffat ◽  
Muhammad Ishfaq ◽  
Afaq Ahmad ◽  
Khalil Ur Rehman ◽  
Fawad Ahmad
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Wheat Straw ◽  
High Strength Concrete ◽  
High Strength ◽  
Optimum Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Strength Concrete ◽  
Straw Ash

This study is supervised to assess the characteristics of the locally available wheat straw ash (WSA) to consume as a substitute to the cement and support in enhancing the mechanical properties of concrete. Initially, after incineration at optimum temperature of 800°C for 0.5, the ash of wheat straw was made up to the desirable level of fineness by passing through it to the several grinding cycles. Subsequently, the X-ray fluorescence (XRF) along with X-ray diffraction (XRD) testing conducted on ash of wheat straw for the evaluation its pozzolanic potential. Finally, the specimens of concrete were made by consuming 10% and 20% percentages of wheat straw ash as a replacement in concrete to conclude its impact on the compressive strength of high strength concrete. The cylinders of steel of dimensions 10cm diameter x 20cm depth were acquired to evaluate the compressive strength of high strength concrete. The relative outcomes of cylinders made of wheat straw ash substitution presented the slight increase in strength values of the concrete. Ultimately, the C-100 blends and WSA aided cement blends were inspected for the rheology of WSA through FTIR spectroscopy along with Thermogravimetric technique. The conclusions authenticate the WSA potential to replace cement in the manufacturing of the high strength concrete.

scholarly journals THEORETICAL MODEL FOR DOUBLE-SKINNED CONCRETE-FILLEDSTEEL-TUBULAR COLUMNS WITH EXTERNAL CONFINEMENT

2015 ◽  
Vol 21 (5) ◽  
pp. 666-676 ◽  
Author(s):  
Chun Xiao Dong ◽  
Johnny Ching Ming Ho
Keyword(s):  
Theoretical Model ◽  
High Strength Concrete ◽  
High Strength ◽  
Imperfect Interface ◽  
Steel Tube ◽  
Interface Bonding ◽  
Strength Concrete ◽  
Tubular Columns ◽  
Strength And Stiffness ◽  
Transverse Steel

Recent advances in the production of super-fine cement and filler technology has made the production of high-strength concrete (HSC) of 120 MPa practicable in the industry. Nonetheless, the application of such HSC in real construction is still limited. One of the reasons that inhibits the use of HSC is the brittleness, which causes HSC structures to fail explosively if the concrete confinement is not adequate. The traditional method of installing transverse steel as confinement is not feasible in HSC structures, as the steel will be too congested to ensure proper concrete placing. To overcome the problem, double-skinned high-strength concrete-filled-steel-tubular (HSCFST) columns has been advocated, which could provide large, continuous and uniform confinement to HSC. However, a major shortcoming of the double-skinned HSCFST columns is the imperfect interface bonding that occurs at the elastic stage that reduces the elastic strength and stiffness of columns. To improve the situation, the authors have verified previously that using external steel rings on the outer steel tube can successfully restrict the dilation of HSCFST columns and thus restore an intact interface bonding condition. As a continued study, the authors will in this paper develop a theoretical model for predicting the uni-axial load-carrying capacity of doubled-skinned HSCFST columns.

The The Characterization and Modeling the Mechanical Properties of High Strength Concrete (HSC) Modified with Fly Ash (FA)

2020 ◽  
Vol 38 (2A) ◽  
pp. 173-184 ◽  
Author(s):  
Saman M. Kamal ◽  
Jalal A. Saeed ◽  
Ahmed Mohammed
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Strength Concrete ◽  
High Strength ◽  
Curing Time ◽  
Strength Concrete ◽  
Statistical Variation ◽  
Study Results ◽  
Concrete Testing ◽  
Linked Model

One of the main challenges facing Civil Engineering community is to modify cement quantity in the mix design by admixtures to enhance the mechanical properties. According to more than 1000 data from literature, mechanical characteristics of concrete modified with FA were discussed. The statistical variation with modeling were achieved by set of data. The cement was replaced up to 70% with FA (weight of dry cement) and by cube of concrete testing up to 90 days of curing time and different w/c ratio. The compressive strength of concrete varied from 18-67 MPa, while, for modified concrete with FA, compressive strength ranged from 21-94 MPa, tensile strength ranged from 1-9 MPa and flexural strengths ranged from 3 - 10 MPa. The w/c ratio of concrete modified with FA varied from 0.24-0.53, also the FA content varied from 0-50 %. Vipulanandan correlation model was effective by connecting mechanical properties and compare with Hoek-Brown model. The nonlinear model was used to investigate the effect of FA on properties of normal and high strength concrete. Study results presented a worthy correlation between compressive strength and curing time, w/c ratio and FA content. By using the interactive linked (model) for compressive, tensile, and flexural strengths of concrete quantified well as a function of w/c ratio, curing time and FA content by using a nonlinear relationship.

Experimental Study on Compressive Bearing Capacity of High Strength Concrete-Filled Steel Tube Composite Columns

2011 ◽  
Vol 368-373 ◽  
pp. 410-414 ◽  
Author(s):  
Hong Zhen Kang ◽  
Lei Yao ◽  
Xi Min Song ◽  
Ying Hua Ye
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Test Results ◽  
Concrete Filled Steel Tube ◽  
Composite Columns ◽  
Strength Concrete ◽  
Axial Compressive Strength

To study axial compressive strength of high strength concrete-filled steel tube composite columns, tests of 18 specimens were carried out. Parameters of the specimens were the confinement index of concrete-filled steel tube, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. Test results show that the concrete-filled steel tube and the reinforced concrete deformed simultaneously in the axial direction before and at the peak value of axial compressive force; after failure of the reinforced concrete, the concrete-filled steel tube can still bear the axial load and deformation; the main influential factors of axial compressive capacity are confinement index, the cubic strength and the stirrup characteristic value of concrete outer of steel tube. The accuracy of the formula of axial compressive strength of composite columns provided by CECS 188:2005 is proved by the test results of this paper.

Mechanical Behaviors of Slender Steel Tubular Columns Filled with Steel-Reinforced High-Strength Concrete

2015 ◽  
Vol 1089 ◽  
pp. 235-238
Author(s):  
Ping Guan ◽  
Lan Xiang Chen
Keyword(s):  
Yield Stress ◽  
High Strength Concrete ◽  
High Strength ◽  
Steel Tube ◽  
Mechanical Behaviors ◽  
Composite Columns ◽  
Strength Concrete ◽  
Tubular Columns ◽  
Finite Element Software ◽  
Mechanical Models

To study on the mechanical behaviors of the new slender steel-concrete composite columns that are named after steel tubular columns filled with steel-reinforced high-strength concrete(STSRHC), the mechanical models of slender STSRHC are established for the analysis with the finite element software ABAQUS. There are seven influencing factors on the mechanical behaviors of slender STSRHC, they are: slender ratio, eccentricity, the thickness of steel tube, the yield stress of steel tube, the yield stress of inserted steel, the cube strength of high-strength concrete, the shape of inserted steel cross section. The results show the results calculated by software have good agreements with the tested ones; slender ratio, eccentricity and the thickness are the most effective factors on the mechanical properties of slender STSRHC.

Mechanical Properties of Steel Fibre-Reinforced High Strength Concrete with High early-Age Strength Used in Freezing Shaft Lining

2012 ◽  
Vol 174-177 ◽  
pp. 1388-1393
Author(s):  
Hai Qing Song ◽  
Teng Long Zheng
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Flexural Strength ◽  
High Strength Concrete ◽  
Steel Fibre ◽  
High Strength ◽  
Plain Concrete ◽  
Split Tensile Strength ◽  
Strength Concrete

Plain concrete is susceptible to cracking under aggressive environment such as in freezing shaft. And addition of steel fibres in plain high strength concrete is proved to be effective in cracking resistance and brittleness improvement, etc. This paper presents results of experimental investigation carried out to study the mechanical properties of steel fibre-reinforced concrete having volume fractions of 0.38%, 0.51% and 0.64% for two types of fibres respectively. The results of this study revealed that there is an increase for all the mechanical properties such as compressive strength, split tensile strength, modulus of elasticity and flexural strength. Enhancement for split tensile strength and flexural strength is more evident than compressive strength.

scholarly journals Reduction of Postfire Properties of High-Strength Concrete

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Neno Torić ◽  
Ivica Boko ◽  
Bernardin Peroš
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
High Temperature ◽  
Ambient Temperature ◽  
Modulus Of Elasticity ◽  
High Strength Concrete ◽  
High Strength ◽  
Maximum Temperature ◽  
Secant Modulus ◽  
Strength Concrete

This paper presents an experimental study of behaviour of high-strength concrete at high temperature. Reduction of the mechanical properties of concrete was determined starting from the period when the concrete specimens were heated to the maximum temperature and cooled down to ambient temperature and the additional 96 hours after the initial cooling of the specimens. The study includes determination of compressive strength, dynamic and secant modulus of elasticity, and stress-strain curves of concrete specimens when exposed to temperature level up to 600°C. The study results were compared with those obtained from other studies, EN 1994-1-2 and EN 1992-1-2. Tests point to the fact that compressive strength of concrete continues to reduce rapidly 96 hours after cooling of the specimens to ambient temperature; therefore indicating that the mechanical properties of concrete have substantial reduction after being exposed to high temperature. The study of the dynamic and secant modulus of elasticity shows that both of the properties are reduced but remain constant during the period of 96 hours after cooling. The level of postfire reduction of compressive strength of the analyzed concrete is substantial and could significantly affect the postfire load bearing capacity of a structure.

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