| 摘要 |
According to the invention, the tubular preform radially mouldable between a folded state in the longitudinal direction and a susbstantially cylindrical unfolded state, in order to form in situ a rigid tube section, comprises a flexible leakproof inner envelope (6), the perimeter of which is equal to the inner perimeter of the tube section and, on the exterior of this inner envelope, reinforcement in the form of a filamentary structure comprising a plurality of fibres impregnated with a hardening resin, the fibres (3) being chiefly oriented in the peripheral direction of the preform, each of these fibres (3) extending for more than one turn and co-operating by contact with the adjacent fibres, such that the adjacent fibres are able to slide in relation to the others in any state of the preform other than its unfolded state where, under internal pressure, they are mutually immobilized by the friction generated between them due to a capstan effect. |
