CONCRETE FILLED TUBES SUBJECTED TO IMPACT LOADING

Abstract

What is CFST? CFST is a composite system that stands for Concrete Filled Steel Tubes. Composite system are the structures in which the components comprise of at least two different material having the different physical and chemical properties like Elasticity, density etc. CFST consists of a steel tube and concrete core. Steel tube is used as the outer material which is in-filled with concrete. CFST can be casted of desired cross-section but mostly square, rectangular and circular sections are used. A typical cross-section of CFST is shown in figure 1.1. Being the composite material CFST owes the advantages of two different materials. Steel tube provides the confinement to the concrete core that enhances the properties of concrete and delayed the buckling locally of steel tubes. The steel at the outer perimeter of CFST performs most effectively in tension and bending. It also enhances the stiffness as the steel lies furthest from the centroid and the combination of this with the large modulus of elasticity. The concrete core gives the greater contribution to resisting axial compression. They are widely used in Multi-storey and highrise buildings as columns and beam-columns