THE TORSIONAL STIFFNESS OF SUPPORT DIAPHRAGMS IN BEAM AND SLAB BRIDGES

The first part of this 2-part report describes the results from eight quater-scale model diaphragm beams with two different widths and with different reinforcement details; the second part presents the results of analyzing three bridge decks with various values of torsional stiffness of the diaphragm beams. The influence of the latter on the moment distribution in the deck and the design of the diaphragm beams is discussed. The study indicates that the composite beams behave monolithically prior to cracking and are stiffer than their monolithic counterparts after cracking. It is suggested that the torsional stiffness to be used in design should be 50 percent of that of the in situ section. It is recommended that the diaphragm should permit the provision of continuous reinforcement through the precast beams, and that the in situ concrete should extend beyond the ends of the precast beams.

• Corporate Authors:

  Cement and Concrete Association

  52 Grosvenor Gardens
  London SW1W 0AQ,   England 
• Authors:
  • CLARK, L A
  • West, R
• Publication Date: 1975-8

Media Info

• Features: Figures; References; Tables;
• Pagination: 20 p.

Subject/Index Terms

• TRT Terms: Beams; Bridge decks; Bridge design; Bridges; Composite materials; Concrete; Continuously reinforced concrete pavements; Engineering moments; Fracture mechanics; Precast concrete; Slabs; Stiffness; Structural design; Structural diaphragms; Structural supports; Torsion
• Uncontrolled Terms: Composite beams; Moment distribution
• Old TRIS Terms: Continuous reinforcement; Diaphragms; Supports
• ITRD Terms: 3472: Beam; 3482: Bridge deck; 9005: Composite; 4755: Concrete; 9006: Continuous; 5211: Cracking; 6226: In situ; 4792: Precast concrete; 3471: Reinforcement (in mater); 3491: Slab; 5931: Stiffness; 6255: Test; 5512: Torsion
• Subject Areas: Bridges and other structures; Highways;

Filing Info

• Accession Number: 00128576
• Record Type: Publication
• Report/Paper Numbers: 42.510 Tech. Rpt.
• Files: ITRD, TRIS
• Created Date: Mar 10 1976 12:00AM