NOTES ON THE PREPARATION AND GROUTING OF DUCTS IN PRESTRESSING CONCRETE MEMBERS

NOTES ON THE DUCTS THEMSELVES INCLUDE DISCUSSION OF THE SPECIAL DESIGN FEATURES REQUIRED WHERE GROUTING IS TO BE EMPLOYED, THE TYPES OF DUCT IN COMMON USE (CORED DUCTS AND CORRUGATED METAL DUCTING) AND THE NEED TO INSPECT FOR FLAWS SUCH AS MISALIGNMENTS, DENTS, SPLITS AND HOLES WHICH CAN RESULT FROM MALFORMATION OR FROM DAMAGE. LIKELY CAUSES OF DAMAGE TO DUCTS AND PREVENTATIVE MEASURES ARE DISCUSSED IN DETAIL TOGETHER WITH REPAIRS THAT CAN BE EFFECTED. METHODS OF TESTING INCLUDE THE USE OF RODS OR COMPRESSED AIR TO CHECK FOR BLOCKAGES, COMPRESSED AIR FOR FLAWS AND CHECKING ALIGNMENT BY THE USE OF RADIOACTIVE MATERIAL IN A DROGUE. NOTES ON GROUTS INCLUDE THEIR PURPOSES ( TO PROTECT THE STEEL AND GIVE A GOOD BOND) AND LIMITING CRITERIA FOR SHRINKAGE ON SETTING, BLEEDING, WORKABILITY AND COMPRESSIVE STRENGTH. SUITABLE MATERIALS ARE NAMED (PORTLAND CEMENT, PORTLAND BLASTFURNACE CEMENT, PURE WATER AND A RANGE OF FINE AGGREGATES). DETAILS OF INJECTION METHODS ARE GIVEN WHICH INCLUDE THE PREPARATIONS THAT ARE NEEDED, FOR BOTH TYPES OF DUCT, THE CONSISTENCY OF THE GROUT, PUMPING EQUIPMENT REQUIREMENTS AND COMPREHENSIVE NOTES ON THE SEQUENCE OF OPERATIONS. IN CONCLUSION NOTES ARE GIVEN ON TESTING THE EFFICIENCY OF THE GROUTING AND MEASURES TO BE TAKEN WHEN GROUTING IN COLD WEATHER. /TRRL/

  • Corporate Authors:

    Cement and Concrete Association

    52 Grosvenor Gardens
    London SW1W 0AQ,   England 
  • Publication Date: 1972-11

Media Info

  • Pagination: 5 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00083123
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: R&D Rpt.
  • Files: ITRD, TRIS
  • Created Date: May 1 1975 12:00AM