Load introduction for concrete‐encased steel composite columns using high‐performance materials

Due to the increasing demand for high‐rise buildings and resource‐efficient construction, the demand for innovative construction technologies and materials is growing. High‐performance materials provide resource‐optimized structural solutions providing an important load‐bearing resistance.

However, questions arise about the ductility of structural members using e.g., high‐strength concrete that is particularly important for the shear connectors of composite structures. This paper evaluates the load‐bearing capacity of the headed stud shear connectors arranged in the load introduction zone of encased composite columns using concrete compression strength classes C50/60, C80/95, and C100/115. An experimental study consisting of 32 specific push‐tests for circular and square cross‐sections with an embedded structural steel profile HE 160 B has been investigated. The loading procedure defined in EN1994‐1‐1:2004 Annex B was applied. Eight specimens were initially preloaded for six to twelve months to investigate the impact of the long‐term behavior of the concrete.

Numerical simulations performed in FE code Abaqus® supported the investigation, using a simplified definition of the bond. The results correlated well with the outcomes of the extremital campaign.

The research project thus provides the first approaches to be able to include high‐strength materials in the composite construction regulations for columns in the future.