A Composite Action Duct-Beam System

This paper describes a new method of utilizing steel in building construction, based on a research program Undertaken by Reid & Tarics, Architects-Engineers, for the American Iron and Steel Institute. Specifically the project was intended to generate a structural system to be bid competitively for the URBS (University Residential Building System) Project of the University of California. It appears, however, that the field of application of this concept may have general interest. Basically, the concept is to take advantage of the proven inherent economic advantages of composite design and to combine it with a beam shape (unsymmetrical rectangle) which will allow the beam to serve as an air duct for either warm or cool air. The structural frame of the building thus becomes the primary network of horizontal air distribution, eliminating conventional ductwork in part or in whole. The system has application wherever a central system must be used for ventilation. It has the advantages of minimum steel weight and long span economy inherent in a composite steel structure, coupled with the obvious savings in ductwork and story height.