| 摘要 |
1500189 Pre-stressed beams J-B MAUQUOY 21 Jan 1975 [22 Jan 1974] 2563/75 Headings E1K and E1W A pre-stressed beam comprises an I section metal beam 3, preferably partially encased in concrete 1 prior to pre-stressing, anchorages 4 on the underside of the lower flange of the beam 3 for two pairs of tensioning wires 6 disposed at two different levels, and guides 5 also on the underside of the beam 3 for maintaining the spacing of the lower pair of wires 6, the inner anchorages 4 preferably having a larger transverse dimension than the outer anchorages 4 so as to function as guides for maintaining the spacing of the upper pair of wires 6. The beam is stressed by tensioning the wires while being supported on supports 10 and held straight by abutments 9 previously lowered into the positions shown. After stressing, further concrete is cast around the assembly of anchorages 4, guides 5 and wires 6, this concrete being allowed to set prior to remoaal of the abutments 9. For Figures see next column |
