A method and apparatus for constructing a multi-storey building. A first slab (22) is formed directly on top of a second slab (21). The slab (22) is formed with a plurality of apertures spread about the slab area. A plurality of extendible prop means (10) are positioned in the respective apertures, the head portion (12) of each prop means being connected to the first slab (22), the foot portion (13) of each prop means being supported by a slab below the first slab (22). The prop means (10) is extended such that the first slab (22) is lifted to its desired position. Once in that desired position, the foot portion (13) of each extended prop means is retracted through its respective aperture to engage the upper surface of the first slab (22) and the process is repeated according to the number of storeys required in the building.
A method and apparatus for raising concrete floor slabs to form a multi-floor structure. Slabs are cast near ground level with apertures cast for well placed columns. The slabs are lifted sequentially, uppermost first, by an air cushion backed up by follower means to hold the slabs safely at any elevation reached. The air cushion is created between the current uppermost slab, the slab below, and the walls of a steel enclosure erected around the stacked slabs and extending upward allowing slabs to travel upward.
A flat-formed arch ring unit includes a linear array of voussoir portions connected along their upper edges. The unit is then archable. A method is provided for forming an archway including the steps of arching one or more the flat formed arch ring units and locating them between two or more foundation blocks or the like. This provides a simple yet effective process and unit for forming an archway. With ease of production, shaping and transportation, making new archways or carrying out repairs of existing bridge archways is significantly faster and cheaper, minimizing disruption and delay to traffic.
