Experimental investigations on Concrete‐Filled Double Steel Tube Columns

Abstract

Concrete‐filled double steel tube columns (CFDST) constitute a structurally efficient and architectonically appealing alternative to conventional solid concrete columns. However, the simplified design concepts in Eurocode 4 are not directly applicable to newly developed high‐performance hollow section composite columns that use high‐strength steel and concrete. The expansion of the application range of the design rules requires comprehensive investigations of the structural behaviour of these innovative composite columns. Therefore, full‐scale slender column tests were performed on high‐strength CFDST specimens, systematically varying relative slenderness and imposed load eccentricity. The experimental results serve as a basis for subsequent numerical studies aimed at formulating a unified, practice‐oriented design concept applicable to a broad range of innovative hollow section composite columns, thereby promoting resource‐efficient, high‐performance composite structures. In this paper, the experimental testing programme for the CFDST and initial findings on the load‐deformation response are presented.