Title:
Composite Response of High-Strength Concrete Confined by Circular Steel Tube
Author(s):
Peter McAteer, John F. Bonacci, and Mohamed Lachemi
Publication:
Structural Journal
Volume:
101
Issue:
4
Appears on pages(s):
466-474
Keywords:
column; confinement; high-strength concrete; strain; stress
DOI:
10.14359/13332
Date:
7/1/2004
Abstract:
Concrete-filled steel tubes (CFSTs) have gained wide acceptance as column elements. Current North American design codes assume the load to be placed across the entire steel-concrete cross section, calculate the independent resistance of the load by the component materials, and determine the composite resistance by superposition. Another form of CFST construction exists where only the concrete surface is directly loaded. In this case, the steel tube serves primarily to confine the concrete core. With the increasing use of high-strength concrete, and the well-documented need for it to be confined, this form of construction warrants consideration. Currently there are no design guidelines specifically for this type of CFST element. This paper addresses this shortcoming in two ways. First, the existing database of these CFST columns is examined. Next, an experimental program is developed to examine the interaction between the steel tube and the concrete core, as indicated by the tube response and the volumetric and axial strain history of the concrete. Expressions are derived for peak and residual load capacity.