FRICTION LOSSES DURING PRESTRESSING. STAGE 1: INVESTIGATION OF COEFFICIENT OF FRICTION FOR SINGLE WIRE AND STAND TENDONS

Loss of load in stressed single wire and strand tendons due to friction between tendon and duct has been measured in a simple curved duct. Tendons used ranged from 7 mm wire to 18 mm drawn strand. As manufactured 'clean', rusty and oiled samples were used in a series of 25 tests. The object of the programme was to isolate variable factors and instrumentation errors in order to obtain an accurate assessment of the tendon/duct coefficient of friction. Particular care was taken to eliminate loss of load due to factors such as inaccurate alignment or damage of the ducting. A novel system was used to measure the loss in tendon tension across the duct. The results, therefore, compare the value of the coefficient of friction between duct and differing types and conditions of tendons, but do not give a final figure for use in design. They show the coefficient to increase with increase in diameter of tendon but apparently to be independent of tendon load for any given duct size. Rust on the tendon greatly increases the coefficient of friction. (A) /TRRL/

  • Corporate Authors:

    Construction Industry Research & Information Assoc

    6 Storey's Gate
    London SW1P 3AU,   England 
  • Authors:
    • OWENS, A
    • Moore, D R
  • Publication Date: 1974-5

Media Info

  • Features: Figures; Photos; Tables;
  • Pagination: 28 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00131496
  • Record Type: Publication
  • Source Agency: Transport and Road Research Laboratory (TRRL)
  • Report/Paper Numbers: No. 56 Tech. Note
  • Files: ITRD, TRIS
  • Created Date: May 14 1976 12:00AM