Moulding reinforced concrete into U-channels with high walls - carriage-borne upper half of mould having raked leading edge

摘要

A U-section channel is formed between a fixed lower mould and a sliding upper mould, with the concrete poured just in front of the upper mould. When the walls of the channel are high, the wet concrete mixture cannot maintain a vertical profile at the leading edge. The inner mould must have a similar profile if the leading edge of the concrete is to be accessible for filling, and the chute (18) which conveys the concrete from the hopper (15) must have its distributing edge directly above this same raked profile. Vertical plates (20a, 20b) at the edges of the upper mould reduce the poured concrete to the required thickness; the section of the upper mould next behind is vibrated to compact the concrete (vibrators 13); behind that again is a non-vibrated section which gives a smooth finish to the work as the carriage slides it forward (rails 2, wheels 5).