Steel Deck Fastening Systems
1.1 Steel Deck Fastener Design and Selection
1.1.2 Steel Deck Diaphragm Design and Theory 1.1.2.1 General Discussion
A steel deck diaphragm is a horizontal assembly that resists wind , seismic and other lateral forces . A diaphragm can be modeled as a horizontal beam with interconnected floor and roof deck units that act as the beam web . Intermediate joists or beams act as web stiffeners and perimeter beams or reinforcement on the diaphragm perimeter act as the beam flanges . Figure 1 , based on graphics from the Steel Deck Institute ( SDI ) Diaphragm Design Manual , depicts a roof deck diaphragm model .
Design of steel deck diaphragms has traditionally been done using the Steel Deck Institute ( SDI ) Diaphragm Design Manual or Technical Manual ( TM ) 5-809-10 Seismic Design for Buildings , Departments of the Army , Navy and Air Force ( Tri-Services Design Manual ). Both methods provide the basic equations for determining the strength and stiffness of the diaphragm considering the following parameters :
1 . Steel Deck Profile Type and Thickness 2 . Supporting Steel Frame Spacing or Deck Span
3 . Frame Fastener Type and Spacing ( connector for steel deck to steel frame )
4 . Sidelap Fastener Type and Spacing ( connector for steel deck panel edge to edge )
5 . Safety Factors ( ASD ) or Resistance Factors ( LRFD / LSD ) based on load type ( wind , seismic , other ) and fastening type ( mechanical , weld )
ICC Evaluation Services recognizes both design methods as acceptable in AC43 , Acceptance Criteria for Steel Deck Roof and Floor Systems . An ICC Evaluation Service Report ( ESR ) based on ICC-ES AC43 provides recognition for use with the IBC . Hilti deck fasteners are currently listed in the SDI DDM03 and Appendix VI , VII and VIII and were evaluated in ICC-ES ESR-3592 , ESR-2776 and ESR-2197 . Hilti deck fastener performance with proprietary sidelap clinching systems is also documented in ESR-1735P , ESR-1116 , ESR-1169 , ESR-1414 and ESR-2408 . Additional industry research on quasi-static and seismic / cyclic load performance of diaphragms is ongoing . Other system approvals and evaluation reports are pending .
1.1.2.2 Fastener Test Programs
Many small element and full scale test programs have been conducted using Hilti deck fasteners to evaluate their performance .
1 . Small Element Connection Tests
Figure 1 : Diaphragm Model
Small element connection tests are used to determine fastener pullout , pullover and lap-joint shear strength and stiffness with sheet steel and base steel representative of typical construction . The data is analyzed and used in a predictive model to calculate the performance of the larger steel deck diaphragm assembly or system . These tests are conducted in accordance with the following standards , and shown in Figure 2 .
• AISI S905 Test Methods for Mechanically Fastened Cold- Formed Steel Connections
• ASTM E1190 Standard Test Methods for Strength of Power-Actuated Fasteners Installed In Structural Members
• ICC-ES AC70 Acceptance Criteria for Fasteners Power Driven Into Concrete , Steel and Masonry Elements
• ICC-ES AC118 Acceptance Criteria for Tapping Screw Fasteners
4 Hilti , Inc . ( US ) 1-800-879-8000 | www . us . hilti . com I en español 1-800-879-5000 I Hilti ( Canada ) Corp . 1-800-363-4458 I www . hilti . ca I PTG Decking Supplement 2014