COCRETE FILLED STEEL TUBES

PRESENTAION BY:

K.NAVEEN CHAKRAVARTHY

Roll No-233049

CONTENTS 1. COMPOSITE CONSTRUCTION2. COMPOSITE COLUMNS3. DIFFERENT TYPES OF COMPOSITE COLOUMNS4. CONCRETE FILLED STEEL TUBES5. SILENT POINTS OF CONCRETE FILLED STEEL TUBES6. BEHAVIOR UNDER AXIAL LOAD7. BEHAVIOR UNDER SEISMIC LOAD8. CREEP AND SHRINKAGE9. FIRE PERFORMANCE10. CONSTRUCTION ASSPECTS11. BEAM COLOUMN CONNECTION DETAILS12. CONCLUSION13. REFERENCE

COMPOSITE CONSTRUCTION

Different materials arranged in optimum geometric configuration, with the aim that only the desirable property of each material will be utilized by the virtue of its designated position. The structure is then known as composite structure and the method of construction is known as composite construction.

COMPOSITE COLUMNS

Compression members in which the steel elements act compositely with concrete element to resist the compressive forces are known as composite columns..

DIFFERENT TYPES OF COMPOSITE COLOUMNS

CONCRETE FILLED STEEL TUBES

Concrete Filled Steel Tube (CFT) structural system is based on filling the steel tube with high strength concrete.

The CFT structural system promises excellent structural characteristics like strength, rigidity, deformation capacity and fire resistance in every field of construction..

SALIENT FEATURES OF CFT

Higher load caring capacity permits more floor space area.

Good ductility and energy absorption. Excellent earthquake resistance. Stiffness in horizontal plane. No need of formwork. Speed construction. Fire resistance.

BEHAVIOR UNDER AXIAL LOAD Experimental study done in HEAVY

STRUCTURAL LABOROTARY RANDWIK.

Load-deflection results for : (a) hollow steel tube section and (b) concrete filled steel tube section.

Failure mode for : (a) hollow steel tube section and (b) concrete filled steel tube section.

BEHAVIOR UNDER SEISMIC LOAD

CREEP AND SHRINKAGE

FIRE PERFORMANCE Concrete filled steel tubes have good fire

resistance property. The inner concrete core acts as a cooling

agent. Redistribution of temperature will take place

from steel tube to concrete core. External fire protection can be eliminated

thus reducing cost and increasing floor space area.

CFT’s WHEN COMPARED WITH OTHER STRUCTURES

CONSTRUCTION ASPECTS No need of form work which reduces

materials, crainage, labour. Temporary bracings are provided. Concrete can be filled from the top or can be

pumped through hole from the bottom. Vibrators are not necessary if concrete is

filled from the bottom. Load resistance of the column can vary by

changing the grade of concrete.

CONSTRUCTION SITE

BEAM COLOUMN CONNECTION DETAILS

SOME OF THE TALLEST BUILDINGS WERE CFT’S ARE USED

The Taipei 101 tower, one of the tallest building in the world.

COLUMNS IN TAIPEI 101 Two super columns at each face. Two sub super columns at each face. 16 column at core. Columns filled with concrete till 62nd floor.

Tower PalaceIII, Seoul, Korea.

71 storey residential building,264m high.

Queens Central Tower, Honkong

Pacific Century Pacific Century Palace,Palace,

Marunouchi, Marunouchi, Tokyo.Tokyo.

CONCLUSION The load carrying capacity and behavior (stiffness)

in compression, bending, and shear are excellent and superior to reinforced concrete.

The strength of the concrete is enhanced by the confining pressure induced by the steel.

The compressive load carrying capacity of the concrete can be fully utilized because of the brittle nature of failure is prevented by the containing tube.

CFT’s have good ductility and energy absorption and thus excellent for use in seismic region.

Speed and economic construction can be achieved.

REFERENCE:

S.T.Zhong and C.D. Goode (NOV.2001) “Composite Construction for column in high rise building”, Proceedings of institute of civil engineering structure and building.

Colin B. Brown (MAY1999) “Composite action in concrete filled tubes”, Journal of structural engineering.

Shaw-Song, Ching-Chang, and Jiun-Hong,” Structural Design of Composite Super –column for the Taipei101 Tower”. egc.com.tw

www.ste.chalmers.se

www.civ.unsw.edu,au

www.seaoi.org

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