Feasibility of Composite Reinforcement for Heavy Structure

Abstract

Composite sections are often used for tall bridge columns to reduce their mass, reduce seismic inertia forces,
and reduce foundation forces. However, the seismic performance of Composite columns is still not fully understood
although a few experimental works were conducted previously. The behavior of nine flexure-dominant circular
Composite reinforced concrete cubes, under axial loading is investigated through a experimental studies. Comparison
between test results of nine Composite and nine solid reinforced concrete cubes is presented. All of the 18 cubes were
designed as Composite sections to resist combined load of bending, torsion and shear. Every pair (one Composite and
one solid) was designed for the same load combinations and provided similar reinforcement. Test results showed that
average 15% rise in Composite circular bar’s compressive strength compare to regular bar. All solid beams cracked and
failed at higher loads than their counterpart Composite beams. The smaller the ratio of torsion to bending the larger the
differences in failure loads between the Composite and solid beams. The longitudinal steel yielded while the transverse
steel experienced lower strain values.