Steel Tube Institute Written

Written

Course Information
Filling steel Hollow Structural Section (HSS) columns with concrete achieves increased compression capacity through steel and concrete composite action. Additional benefits to concrete-filled HSS columns include increased fire endurance (research has shown up to 3 hours depending on the level of loading), reduction in the requirements for costly coatings for fire protection, and even increases in connection capacity in some configurations.

While engineers may be aware of these benefits, often questions arise about the practical aspects. Which type of concrete should be specified? What are the limitations? How are connections affected? This article provides guidance on the benefits of concrete-filled HSS with a primary focus on beam-column design. The 2016 Specification is used for this discussion and is referred to as AISC 360-16.

Author
Jason Ericksen, S.E.; Kim Olson, P.E.; and Mike Manor, P.E., MLSE; Technical Consultants to the Steel Tube Institute

Learning Objectives
At the conclusion of this article, the reader should be able to:

• Understand how filling steel hollow structural section (HSS) members with concrete increases strength through composite action.

• Be aware of the pros and cons of filling HSS with concrete.

• Know the design recommendations for composite HSS framing members.

• Realize the effects that concrete filling has on connections to the HSS member.