Title:
The Un-Shored Composite Slab on Metal Deck Part I, Construction and Behavior
Author(s):
Eldon Tipping and Bryan M. Birdwell
Publication:
Symposium Paper
Volume:
338
Issue:
Appears on pages(s):
57-64
Keywords:
composite, deflection, gauging, level, metal deck
DOI:
10.14359/51724728
Date:
3/1/2020
Abstract:
This is the first of a three-part series, the goal of which is to provide the designer and contractor with tools
necessary to produce deflected slabs on metal deck that are essentially level. This first part provides a general
description of the components of a composite slab on metal deck including the behavior of each of the components
prior to concrete placement and after the concrete hardens. Elements impacting the ability of the
design/construction team to produce level deflected floors are presented and discussed. Fabrication tolerances for
structural steel are published by the American Institute of Steel Construction (AISC) and impact the relative
elevation of erected beam/column connections prior to concrete placement. Deflection of the erected floor frame
under the weight of fresh concrete is impacted by choices made by the designer regarding the use of Allowable
Strength Design (ASD) and Load and Resistance Factor Design (LRFD). Uncertain net deflections of the
supporting structural steel frame provide challenges for the contractor in his efforts to provide sufficient concrete in
the appropriate locations during initial strike-off to off-set the structural steel deflection. Implications of gauging up
off the supporting structural steel versus using a rod and level for initial concrete strike-off are presented and
discussed. The importance of construction joint location is addressed, and recommendations are presented.