An experimental study on FRC infilled steel tubular columns under eccentric loading

Concrete filled Steel tubular columns have become more popular as the requirements on the performance of steel structures increased as in case of tall buildings all over the world. These types of columns offer a number of advantages attaining economy in the construction and have been used in variety of applications. Because of their excellent ductility these have been used in earthquake resistant structures. This paper presents an experimental study on the behavior of both plain and fiber reinforced concrete filled slender steel tubular columns eccentrically loaded in compression to failure. The composite columns have different lengths varied from 11D to 28D and diameter to thickness ratio of the steel tube is 38. The column strength, load-strain relationships, load-mid height deflection relationships and failure modes were measured from the tests. Companion tests on six numbers of similar empty steel tubes were also undertaken to highlight the beneficial effects of composite column. The study has shown that fiber reinforced concrete filled steel tubular slender columns offer a significant increase in the column strength and ductility compared with plain concrete filled steel tubular slender columns.