As part of a continuing examination of concrete quality in New Zealand highway bridges, 120 bridges in the South auckland-waikato region were surveyed to examine the frequency and magnitude of common concrete defects. Significant features seen include: (1) poor compaction, distortions, lack of waterproofing between deck slab and planks on early examples of prestressed beams and planks; (2) efficient dripformers and drainage ports through bridge decks which were effectively sleeved with linings extending below the soffit; (3) frequent plastic shrinkage cracking on deck slabs; and (4) frequent crazing, some of which may be attributable to alkali aggregate reaction (AAR). The following conclusions were drawn from this work, when combined with information from bridge surveys in taranaki, gisborne, hawke's bay, wairarapa, manawatu and wellington: (a) environmental effects on durability include exposure to sea salts leading to corrosion of reinforcement; (b) AAR may occur with certain aggregates; (c) most poor ratings were given to older bridges; and (d) defects related to construction are more common that durability problems.

  • Corporate Authors:

    Ministry of Works and Development

    P.O. Box 30845
    Gracefield, Lower Hutt,   New Zealand 
  • Authors:
    • Freitag, S A
    • ROWE, G H
  • Publication Date: 1987-6


  • English

Media Info

Subject/Index Terms

Filing Info

  • Accession Number: 00498903
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: 4-87/6
  • Files: ITRD, TRIS, ATRI
  • Created Date: Sep 30 1990 12:00AM