An attempt has been made to use this composite structural member as a column with a modification of flutes on the steel tube which enhances the aesthetics and development area of sheet by which the moment of inertia gets increased by about 17 to 40 % for rectangular flutes and 9 to 23 % for triangular flutes. Confining concrete by providing triangular and rectangular shape fluted steel tube has...

Suppression of softening in the load-deflection diagram of concrete-filled tubular columns and spiral columns is proposed to serve as a design criterion helping to avoid the size effect and explosive brittle character of collapse. To this end, the recently developed ‘‘tube-squash’’ tests, in which a short concrete-filled steel tube is squashed to about a half of its original length and allowed ...

This report presents the results of an experimental study that was conducted to investigate the effects of key parameters on the compressive behavior of fiber reinforced polymer (FRP)concrete-steel double-skin tubular columns (FSDT). Hybrid FSDT columns have been introduced as a new form of hybrid columns. They consist of an outer tube made of FRP and inner tube made of steel, with sandwiched c...

A method is presented to predict the complete stress-strain curves of concrete subjected to triaxial stresses, which were caused by axial load and lateral force. The stress can be induced due to the confinement action inside a special-shaped steel tube having multiple cavities. The existing reinforced confined concrete formulas have been improved to determine the confinement action. The influen...

This paper presents research documenting the local damage progression in rectangular concrete-filled steel tube beam-columns and connections in composite frames. Local damage is quantified through the development of damage indices based upon results of worldwide experiments. A fiber-based finite element formulation is also introduced for assessing global capacity and seismic demand.

Concrete columns confined with high-strength fiber reinforced polymer (FRP) composites can enhance the strength as well as the ductility of such structures. In recent years, the use of FRP composites to repair and strengthen existing reinforced concrete (RC) structures has been widely used. When the columns of existing RC structures are wrapped with FRP composites, the core concrete of such col...

Steel-reinforced concrete (SRC) columns, which are classified as composite columns, became the most widely used in recent years; because of their extensive advantages over the reinforced concrete and the steel columns. In this paper, the ductility index and its influential factors were explored to investigate the behavior of SRC columns. A straightforward approach was then proposed by establish...