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A new composite column system using a solid core and an encasing jacket made from (ultra‐)high‐strength structural steel filled with concrete is presented in this paper that can serve as a promising alternative to prefabricated reinforced concrete columns from an economic and constructive point of view. Within the scope of a research project, this topic is being investigated in more detail by means of numerous experimental and theoretical investigations to enable the use of (ultra‐)high‐strength steels in the future. In this article, stub column tests were carried out to assess the resistance to pure compression and to gain insights into the structural performance of this new composite column system. Novel measurement techniques are used to evaluate the different normal force bearing components of the steel core, the hollow steel section, and the filled concrete over the entire loading process. A clear dependence of the load‐bearing behaviour on the cross‐sectional shape and the load introduction form (full‐surface load introduction vs. load introduction via the core surface) was observed. [ABSTRACT FROM AUTHOR]

Due to price developments, steel composite columns have lost significant market shares to prefabricated reinforced concrete columns in recent years. Using high‐strength steel (HSS) in composite columns may offer a way of reviving the market for these kinds of columns. There are different ways of using HSS for composite columns, however, many are associated with the use of welds. Welding of HSS can lead to cold and hot cracks, while also causing high residual stresses which can lead to a decrease of the load bearing capacity. Hollow section composite columns with embedded solid core cross‐sections and using HSS may offer a way to solve this problem. Round hollow sections with embedded solid core as a composite column have so far only been investigated for steel grades up to S460. Within the scope of German FOSTA research project P1501, a concept for a test setup is derived to investigate hollow sections with embedded solid core as a composite column made of HSS. The experimental results will be used as the basis for further numerical studies, which will be discussed within the scope of this paper. Based on these models, parametric studies will be conducted in the future to validate design concepts. [ABSTRACT FROM AUTHOR]

Universal high‐performance columns made of high‐strength steels without welding In recent years, steel‐concrete composite columns made of normal‐strength steels are seldom used owing to the economic and technological advantages of precast reinforced concrete columns. Though, the use of high‐strength structural steels bears high potential for the efficient production of composite columns with excellent structural performance that are economically competitive to precast concrete columns, there are currently major obstacles to use of the ultra‐high‐strength steels (UHSS) in Germany. Hollow section composite columns with embedded high strength steel core without welded connections provide an opportunity to regain lost market share. A research project, funded by the AiF (Arbeitsgemeinschaft industrieller Forschungsvereinigungen), is intended to explore the potential of UHSS composite columns by experimental and theoretical investigations. The present paper demonstrates the concept of such composite columns with UHSS and gives first exciting insights into the research results. In addition to column tests under ambient and fire conditions, small scale tests are necessary to investigate various influencing factors and to create the basis for new and easy to use design and construction principles that allow efficient application. [ABSTRACT FROM AUTHOR]