Patent ID: 7708917

Claim:
A method for casting at least two batches of (1) multiple beams with determined length that may vary between batches or (2) a hollow core slab with a determined length that may vary between batches, said slab having more than one longitudinal hollow core, the method comprising: (a) using a slipforming apparatus movable with respect to a bed, said apparatus comprising: (i) forming members for forming beam profiles or hollow cores, said members being supported at their upper portion, each forming member comprising a basic part and an extension part attached to the basic part, and (ii) side walls for forming the edges of the beams or hollow core slab, (b) preparing a first batch by: (i) feeding a mass to form the lower portion of the beams or of the hollow core slab, and (ii) bringing the forming members onto the lower portion of the beams or the slab and additional mass being fed between and onto the extension parts, wherein the heights of the hollow cores are determined by the heights of the extension parts or wherein the heights and/or form of the beams is determined by the heights of the extension parts, (c) modifying the forming members by detaching only one or more extension parts of the forming members and attaching one or more extension parts with a different size, (d) preparing a second batch by: (i) feeding a mass to form the lower portion of the beams or of the hollow core slab, and (ii) bringing the forming members onto the lower portion of the beams or the slab and feeding additional mass between and onto the extension parts of the forming members, wherein the heights of the hollow cores are determined by the heights of the extension parts of the forming members or wherein the heights and/or form of the beams is determined by the heights of the extension parts of the forming members, wherein the second batch has a difference in the height(s) of the hollow cores or the height(s) and/or form of the beams resulting from the changed one or more extension parts of the forming members.