| 摘要 |
<p>Weight is reduced, esp. in ceilings made from concrete reinforced with steel bars, by providing cavities in rectangular units with flat external surfaces. The cavities are made in each element, during casting, by a number of identical hollow bodies, made of plastics or other material, and these remain in the element. These bodies are pref. of cubid shape, and are brought together with sets of four pipe sockets to form a square cavity pattern, filling the whole element. They pref. open out at the sides into channels for inflow of warm air, hastening drying; and when built in they can be heated, ventilated or fitted with cables. This reduces weight to a min, while leaving ample room for steel reinforcement.</p> |
