| 摘要 |
A plurality of cables to be prestressed and made a part of the final concrete slab, each have their ends secured within a plate with the overall arrangement of wires or cables being of a geometry substantially that of the desired final structural unit. A pair of lever bars pivotally related at their ends are connected to the plates such that when pivoted into straight line relation, the plate securing the ends of the cables are separated from one another, placing the wires in tension. The entire set of stressed cables and lever bars is lifted as a unit and placed onto a horizontal surface having upstanding means received through openings in the plates. Adjustment screws secure the plates to the upstanding means on the horizontal surface, after which the lever bars are removed. Concrete is poured over the tension cables, forming the structural slab, after which on setting up, the end plates are removed from the wires, leaving the prestressed concrete slab with implanted tension wires.
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