| 摘要 |
A method of manufacturing pre-stressed hollow core concrete panels comprises pouring wet concrete into a pre-stress bed 2 comprising: retaining walls 10,11,12,13 surrounding the panel mould and tubes 30 suspended between two substantially parallel retaining walls 12, 13 and retained in place by apertures in said walls, vibrating said wet concrete, and withdrawing said tubes 30. The tubes 30 may be withdrawn before the concrete is set, and may have an arch-like upper profile to facilitate this without the concrete collapsing. The tubes may also be drawn into a further pre-stress bed 3, to allow manufacture of a further panel. The tubes may be withdrawn by means of a winch (41, Figure 4) |
