This paper describes the construction of two prestressed concrete viaducts carrying the Camborne and Scorrier by-pass over the valleys of Blowinghouse and Gilberts Combe in Cornwall. Blowinghouse viaduct is 183M long and 39M high and Giblerts Combe viaduct is 176m long and 22M high. Each of the carriageways in the viaducts is carried on a hollow 3-cell concrete box girder of trapezoidal cross section, prestressed longitudinally to give continuity over the piers. Each box is 2.2M deep and has a top flauge width of 12M. Each carriageway is constructed as an independent bridge supported on four piers 1M thick. The viaducts are in an area of former metalliferous mining, and the location of some workings is not completely known; areas most likely to be liable to subsidence were indicated by the consulting engineers, and appropriate measures were taken. A design strength of 45 n/sq.m with a maximum aggregate size of 20mm was selected. The mix specification is given and the concreting sequence and prestressing are described. /TRRL/

  • Availability:
  • Corporate Authors:

    Cement and Concrete Association

    52 Grosvenor Gardens
    London SW1W 0AQ,   England 
  • Publication Date: 1975-9

Media Info

  • Features: Photos;
  • Pagination: p. 32-33
  • Serial:
    • Volume: 9
    • Issue Number: 9
    • ISSN: 0010-5317

Subject/Index Terms

Filing Info

  • Accession Number: 00132313
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Files: ITRD, TRIS
  • Created Date: Jun 23 1976 12:00AM