USE OF HIGH-STRENGTH CONCRETE IN PRESTRESSED CONCRETE BOX BEAMS FOR HIGHWAY BRIDGES

A study was conducted to determine the structural and economic benefits of using high-strength (6,000 to 12,000 psi) concrete in box beams for highway bridges. The goal was to establish a range of application of various beam designs in terms of span capacity. The study focused on long-span, simply supported, prestressed concrete box beams. The application of high-strength concrete was investigated in two ways. First, high-strength concrete was substituted for normal-strength concrete in the design of standard beam sections. Second, to improve structural performance, modifications were made to the geometry of the standard beams in conjunction with use of the high-strength material. In both cases a parametric study was performed to identify the most structurally efficient designs. Results indicate that the maximum attainable span of the box beam can be significantly increased by using high-strength concrete in conjunction with a modified internal void shape. In addition, attainable span lengths were generally longer and had 1/2-in. rather than 0.6-in. strands for the beam sections studied. Those designs found to provide the greatest structural benefit were subsequently examined for their relative cost-effectiveness. Comparisons were made on the basis of a total superstructure cost per square foot of bridge deck. For shorter span lengths, spread box beams 3 ft wide were found to be the most cost-effective. For longer spans, the 4-ft-wide adjacent box sections were less costly. Strand size does not appear to significantly influence the cost of a box beam.

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 12-18
  • Monograph Title: Bridge research
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00603587
  • Record Type: Publication
  • ISBN: 0309050618
  • Files: TRIS, TRB, ATRI
  • Created Date: Feb 28 1991 12:00AM