Abstract: A tube having walls of multi-layer construction, wherein said multi-layer construction includes one or more sub-layers, each said sub-layer consisting of a woven polymer mesh disposed in between one or more outer layers of material selected from the group consisting of paper, poly-propylene and polyethylene, wherein said tube is formed by affixing said sub-layers to each other while said sub-layers are wound around a mandrel.

Abstract: A concrete formwork tube, said tube including: an internal lining; an external lining; and two or more complementary mould segments, adapted to be received between said external and internal lining; each mould segment having an inner face and an outer face; said mould segments, when assembled and substantially restrained by the external lining from relative movement, defining a moulding cavity open towards an upper and a lower end of the formwork; and at least one locking segment, said locking segment adapted to be disposed between two of said mould segments, thereby to tighten the fit of the assembled mould segments inside the external lining.

Abstract: A tube having walls of multi-layer construction, wherein said multi-layer construction includes one or more sub-layers, each said sub-layer consisting of a woven polymer mesh disposed in between one or more outer layers of material selected from the group consisting of paper, poly-propylene and polyethylene, wherein said tube is formed by affixing said sub-layers to each other whilst said sub-layers are wound around a mandrel.