| 摘要 |
<p>Construction products are moulded by mixing the dry constituents, including a proportion of fine particulate material, feeding (1, 2) the mixture into a mould (5), compacting the mixture, removing part (6) of the mould (5), lightly spraying (9) an exposed upstanding surface of the product with setting liquid, removing the product from the mould (5) and allowing it to set. Sufficient fine particulate material to surround the coarse particles and compaction, using vibration (7) of the mould (5) and compression of the mixture, to cause the fine particles to fill the interstices between the coarse particles, provide sufficient support of the exposed surface to prevent collapse or erosion thereof during wetting even though no fibre reinforcement is included in the mixture. Sufficient liquid to wet the product but not to saturate it is applied by the spray (8, 9). </p> |
