GB1179845A - Improvements in segmental pipe construction - Google Patents

Abstract

1,179,845. Pipes; pipe joints. L. I. D. LLEWELLYN. 17 July, 1967 [15 July, 1966], No. 31817/66. Headings F2G and F2P. A circumferential segment 1 for use in conjunction with a plurality of other similar segments in assembling a pipe comprises opposed longitudinal edges at least part of each of which is a part cylindrical bearing surface the axis of which is symmetrically positioned within the thickness of the segment or a continuation thereof, one or both of the bearing surfaces having thereon a layer of friction-reducing material, e.g. PTFE. The segment is of an inherently non-flexible material such as concrete, ceramics or hollow sheet steel box units. Each segment may be provided with one projecting and one inwardlyextending bearing surface. The outer edges of the inwardly extending bearing surfaces may be cut back (Figs. 3, 4, not shown). The bearing surfaces may extend over only part of the edges, the remainder thereof being cut back (Fig. 4, not shown). Two adjacent projecting bearing surfaces may be connected by a coupling unit having two female bearing surfaces. Two segmental pipes with radial flat faces may be connected by a T-cross-sectioned, annular gasket, a strapping band being provided therearound (Fig. 6, not shown). The fastening of the band allows the band to slip on the application of a load above a predetermined level as the culvert portions are deformed and thus increase in circumference. The ends of the segments may be offset to the circumference of the pipe to be formed (Fig. 7, not shown), a thin strip of plastics material being interposed between adjacent segmental pipes.