types of composite column their performance indices

1. INTRODUCTION
 What is steel-concrete composite column?
A steel-concrete composite column is a compression member, comprising either a concrete
encased steel section or a concrete filled tubular section of hot-rolled steel and is generally
use as a load-bearing member in a composite framed structure.
 Types of steel-concrete composite column
• Fully or partially concrete encased steel section.
• Concrete filled steel tube section.
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2.  Concrete Filled Steel Tube Column (CFST)
1. Circular Concrete Filled Steel Tube Column (CCFST)
2. Rectangular Concrete Filled Steel Tube Column (RCFST)
3. Square Concrete Filled Steel Tube Column (SCFST)
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Introduction…

3.  Advantages of Steel-Concrete Composite Column
• It increases the usable floor space area for given strength.
• It has great fire and corrosion resistance when the concrete encased steel columns are
used.
• It provide good enough strength, stability and stiffness to the structure.
• By using composite column, there is no need to provide a formwork to column
• It provides constant outer dimensions of the column over a number of floors so,
architecture detailing and construction becomes easy
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Introduction…

4.  Performance Indices
• Ductility Index (DI) =
𝜹 𝒖
𝜹 𝟖𝟓%
where, 𝛅 𝑢 is the deformation at ultimate load.
𝛿85% is deformation when load falls 85% of ultimate load.
• Strength Index (SI) =
𝑵 𝒖,𝒇𝒊𝒍𝒍𝒆𝒅
𝑨 𝒄 𝒇 𝒄𝒌+ 𝑨 𝒔 𝒇 𝒚
𝑁 𝑢,𝑓𝑖𝑙𝑙𝑒𝑑 is ultimate load of concrete filled specimen
𝐴 𝑠 = area of steel, 𝐴 𝑐 = area of concrete
𝑓𝑦 is yield strength of steel and 𝑓𝑐𝑘 is characteristic strength of concrete.
• Concrete Contribution Ratio (CCR) =
𝑵 𝒖,𝒇𝒊𝒍𝒍𝒆𝒅
𝑵 𝒖,𝒉𝒐𝒍𝒍𝒐𝒘
𝑁 𝑢,𝑓𝑖𝑙𝑙𝑒𝑑 is Ultimate load (filled) and 𝑁 𝑢,ℎ𝑜𝑙𝑙𝑜𝑤 is Ultimate load (hollow)
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Result and Discussion…

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