AISC - DESIGN GUIDE 36
Design Considerations for Camber
|Publication Date:||1 January 2020|
OBJECTIVE AND SCOPE
Advances in technology and analysis methods over the last few decades have led to more efficient structural designs and an expectation by clients that most members within the building system will be optimized. However, there is not always a single or obvious "optimal" solution. In steel building structures, it can be as much art as science, balancing the demands of strength against the demands of serviceability and economy. When designing horizontal members that support gravity loads from floors or roofs, one of the tools in the structural engineer's toolbox for dealing with these conflicting demands is incorporating camber into their designs.
Unlike many situations engineers encounter, there is no specific right or wrong answer dictating how to incorporate camber into member designs. The intention behind the development of this Design Guide is to educate the industry on some of the pros, cons, and pitfalls associated with specifying camber for steel floor or roof members to enable a practicing engineer to make informed decisions in evaluating the best solution for their specific project. There are already several published articles that address various aspects of cambering beams (Kloiber, 1989; Winters-Downey, 2006; Criste, 2009); the objective of this Design Guide, therefore, is to collate this knowledge into a single resource and expand past discussions where appropriate. By addressing the influence of camber on the design of different member types, such as beams or trusses, and explaining the fabrication and erection processes utilized to achieve the design requirements, engineers can make smarter and more cost-effective choices in optimizing building designs.
Camber design, especially for composite floor systems, is a complex steel design problem. The successful use of cambered steel beams requires the proper placement of concrete on the structure. An appendix, Floor Levelness, has been included in this Guide to provide an overview of the interaction of the steel structure with current concrete placement practices.