This paper discusses experience of strengthening about 50 concrete box girder bridges in France since 1970. Only two of them needed a second strengthening, and this was only due to an over-optimistic analysis of their condition before strengthening. No new structural disorders have yet appeared in the other bridges. The three principal types of crack disorders, observed in prestressed concrete bridges with box girders or ribs, are: (1) cracking due to insufficient bending strength; (2) diffusion and entrainment cracking; and (3) 'downward thrust' cracking. The amount of additional prestressing, required for a damaged bridge, should be evaluated by appraising its mechanical condition. The methods of weighing bearing reactions and decompression moments may help here. The main types of measurement points used are: (1) gauge/transducer pair; and (2) gauge on prestressing tendons. Strengthening by additional prestressing consists of setting additional longitudinal prestressing inside the box girder after injecting the joints when they have been opened enough. The paper describes some methods for: (1) anchoring the prestressing; (2) joint injection; (3) tendon protection; and (4) strengthening a box girder locally.

  • Availability:
  • Corporate Authors:

    International Association for Bridge and Structural Engineering

    ETH-Honggerberg, Wolfgang-Pauli-Strasse 15
    Zurich 8093,   Switzerland  CH-8093
  • Authors:
    • GODART, B
  • Publication Date: 1995-5


  • English

Media Info

  • Features: References;
  • Pagination: p. 81-4
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00712351
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • Files: ITRD
  • Created Date: Oct 24 1995 12:00AM