SUBMITTED BY: PAUL MASCHINENFABRIK
Optical inspection of button heads
on prestressing steel
Button-headed prestressing tendons are used with end-anchorage for wire tendons in railway sleepers and for poles and towers. Button-headed prestressing wires have two advantages over stranded prestressing tendons: there is no loss of pretensioning force due to wedgeslip and there is, in addition to bonding, an end anchorage through which the tensioning force is applied.
The button heads are produced in series, usually on automatic button-heading machines. Process faults that occur during heading can result in geometric irregularities. Cracks can occur during cold working due to fluctuation in...
