FACTORS AFFECTING GIRDER DEFLECTIONS DURING BRIDGE DECK CONSTRUCTION

Problems involved in obtaining the desired thickness of bridge decks were investigated. The study, which was limited to decks longitudinally screeded during construction, included a) field measurements of the girder deflections during construction, and b) theoretical frame analysis of the girder deflections under the field-loading conditions. Two simple supported steel-plate spans were investigated. When full-span length longitudinal screeding is used, the finished grade elevations are set on the screeding edge of the machine and remain independent of the bridge girder deflections, and thus the forming elevations, will in turn have a bearing on the final thickness of a bridge deck. In addition, all factors that in effect cause the deck forming to be too high at the time the concrete is screeded to grade have the potential of causing an inadequate deck thickness. The most significant factors were found to be a) plan dead-load deflection values that are in error, b) differential temperatures existing between the top and bottom flanges of the girders during concrete placement as opposed to those that may have existed when the forming elevations were established, and c) the transverse position of the concrete dead loading at the time a final screeding pass is made over a given point on a span.

Media Info

  • Media Type: Print
  • Features: Figures; References;
  • Pagination: pp 55-68
  • Monograph Title: Bridge design, construction and repair
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00043905
  • Record Type: Publication
  • Report/Paper Numbers: ISBN 0-309-02072-7
  • Files: TRIS, TRB
  • Created Date: Jun 1 1973 12:00AM