Abstract: The present invention discloses apparatus for molding an elongate annular product such as a pole, the apparatus including two outer mold sections (1) relatively movable to form in a first position a substantially enclosed upright molding cavity and in a second position opening said molding cavity, an upright core member (3) is moveable into and out of said molding cavity and when located in said molding cavity defining an annular molding zone (37) between the core member (3) and the outer mold sections (1), filling means (5) arranged to fill the annular molding zone (37) from below, and end capping means (6) arranged to close an upper end region of the zone (37), the end capping means (6) including a filter membrane adapted to allow fluids to escape through the filter membrane while fine solid particles are retained within the molding zone (37).

Abstract: The production of a moulded stressed concrete pipe in which stressed coated tendons are completely embedded in the finished article. The pipe is moulded in at least one longitudinal segment joined only by helically concentrically positioned tendons. The cured segments are then expanded radially to stretch and stress the tendons, the gap formed between the segments being filled with filler material to maintain the stress in the tendons. There is also disclosed a method where the tendons are stressed on a former prior to immersion of the tendons and former in a concrete pour. The former is segmented and collapsible so that the tension in the tendons can be transferred from the former to the concrete when it has cured, thus forming a stressed pipe structure.