Behaviour of a hollow RC column with an internal tube

A non-linear column model of an internally confined hollow (ICH) reinforced concrete (RC) column was suggested and column tests were performed. The suggested column model considered the confining effect and the material non-linearity of the concrete. To verify the suggested column model and to investigate the behaviour of an ICH RC column, quasi-static tests were performed for three different ICH RC columns and a solid RC column. The analysis results by the suggested model were agreeable with the test results, and they showed that it was reasonable to consider the confining effect of concrete. The test results showed that an ICH RC column has high strength, high energy-absorbing capacity, a normal damage index and acceptable ductility, which can be controlled by the thickness and the type of its internal tube.