Title: The Un-Shored Composite Slab on Metal Deck Part III, Level Deflected Slab Strategies

Author(s): Eldon Tipping and Bryan M. Birdwell

Publication: Symposium Paper

Volume: 338

Issue:

Appears on pages(s): 75-87

Keywords: composite, deflection, elevation, gauging, level, metal deck

DOI: 10.14359/51724730

Date: 3/1/2020

Abstract:
This is the third of a three-part series, the goal of which is to provide the designer and contractor with tools necessary to produce level deflected slabs on metal deck. This third part provides the designer and contractor with strategies for producing level deflected slabs on metal deck. An approach by which elevation tolerances can be successfully imposed on the erected steel frame is presented. The method requires that the designer first provide the contractor with desired relative elevation of splice points at each floor level and flexible column splice details. This information, provided by the designer, enables the contractor to establish desired relative elevations that can assist in achieving those tolerances. An effective cambering strategy that recognizes the differing behavior of members framing to columns and those that connect to girders is presented and discussed. The paper finally presents a floor construction/monitoring program that identifies frame behavior during construction and provides both the designer and contractor with the resources necessary to produce level deflected slabs. The program includes pre- and postplacement surveys of structural steel frame, utilization of a controlled method of striking off the concrete, a survey of the completed slab surface, and use of the collected data to respond to unexpected structural behavior. Other tools, including the selective use of “loose shores” or a secondary placement can enable the contractor to produce deflected slabs on metal deck with 80% or more of the surface within a 3/4 inch (19 mm) deep envelope.