Ambient and fire behaviour of eccentrically loaded elliptical slender concrete-filled tubular columns

This paper presents the results of an experimental program carried out on slender elliptical hollow section columns filled with concrete. Given the reduced number of experimental results found in the literature on concrete filled tubular columns with elliptical cross-section, the main objective of this paper is to compare the behaviour of such innovative cross-sections under ambient and high temperatures. The test parameters covered in this experimental program were the load eccentricity (0, 20 and 50 mm) and the type of infill (plain concrete or bar-reinforced concrete). Six room temperature tests were performed, while other six tests were carried out at elevated temperatures, under both concentric and eccentric axial load. Using the results of these tests, the current provisions of Eurocode 4 for room temperature and fire design were assessed, and a specific design proposal developed by the authors was evaluated.