RESTORATION OF STRENGTH IN ADJACENT PRESTRESSED CONCRETE BOX BEAMS. INTERIM REPORT

This research project is aimed at the development and implementation of methods to restore strength to deteriorated prestressed concrete box beams used in bridges built in the early 1950s. This report describes a search of applicable literature and proposes repair schemes. The literature survey produced details of various methods used to restore strength in bridges, but none specifically applicable to adjacent box beams. Two external reinforcement repair schemes were developed. Each includes the removal of deteriorated concrete, placement of epoxy-coated reinforcing steel and/or epoxy-coated, post-tensioned tendons and application of gunite to the soffit of the test beam. In Scheme 1, epoxy-coated reinforcing bars are used. This procedure restores ultimate flexural capacity, but does not restore any lost prestress. It was proposed because it utilizes materials and procedures already familiar to PADOT and is the least costly method envisioned. In Scheme 2, post-tensioned, epoxy-coated strands are used. They restore the full ultimate flexural capacity and most of the lost prestress, but may cause some relatively high tensile stresses on the tops of the beams at their ends.

• Supplemental Notes:
  • Pennsylvania DOT Research Project 84-21.
• Corporate Authors:

  Wiss, Janney, Elstner Associates, Incorporated

  55 Princeton Hightstown Road
  Princeton Junction, NJ  United States  08550

  Federal Highway Administration

  1200 New Jersey Avenue, SE
  Washington, DC  United States  20590

  Pennsylvania Department of Transportation

  Office of Research and Special Studies, P.O. Box 2926
  Harrisburg, PA  United States  17120
• Authors:
  • Preston, H K
  • Osborn, AEN
• Publication Date: 1986-1-31

Media Info

• Pagination: 50 p.

Subject/Index Terms

• TRT Terms: Box beams; Bridges; Coatings; Epoxides; Flexural strength; Posttensioning; Prestressed concrete; Reinforcing steel; Repairing; Shotcrete; Strength of materials; Tendons; Tension
• Uncontrolled Terms: Repairs; Restoration; Soffits; Tensile stress
• Old TRIS Terms: Epoxy
• Subject Areas: Bridges and other structures; Construction; Design; Highways; Maintenance and Preservation; Materials; I24: Design of Bridges and Retaining Walls;

Filing Info

• Accession Number: 00457078
• Record Type: Publication
• Source Agency: Federal Highway Administration
• Report/Paper Numbers: FHWA-PA-85-016, WJE 841207
• Files: TRIS, USDOT, STATEDOT
• Created Date: Jul 31 1987 12:00AM