APPARATUS FOR MAKING PRECAST PRESTRESSED CONCRETE UNITS WITH IMMEDIATELY ACHIEVABLE ADHERENCE BETWEEN CONCRETE MIX AND REINFORCEMENT, IN PARTICULAR PRESTRESSED CONCRETE SLEEPERS

摘要

PCT No. PCT/EP93/00289 Sec. 371 Date Dec. 23, 1993 Sec. 102(e) Date Dec. 23, 1993 PCT Filed Feb. 8, 1993 PCT Pub. No. WO93/15889 PCT Pub. Date Aug. 19, 1993.A method for the manufacture of pretensioned prestressed concrete sleepers wherein, the tensioning wires are taken directly from one or more rolls of wire and are introduced in a longitudinal feed into a tensioning frame, and the tensioning wires (5) are initially anchored at the end thereof located at the front in feed direction. The wires are tensioned by a tensioning device arranged outside of the tensioning frame and resting against the opposite end thereof, and the wires (5) are anchored at the tensioning device; only then are the wires severed by means of a severing device. In this manner, it is possible to combine in a single station the operating stages of cutting to length, introducing and tensioning the wires, which stages in the past were distributed over several manufacturing stations, so that the labor intensive and time consuming manipulation of wires which have been previously cut to length is eliminated.