| 摘要 |
<p>A jointless floor comprising cement and sawdust is prepared by employing means for preventing the failure to set and develop strength, mixing a small proportion of a neutral aggregate with the cement and sawdust, and preparing and laying the composition in such a way as to ensure adhesion to the base. If the sawdust is one that has little adverse affect on cement, such as a soft wood sawdust not containing a high proportion of larch or Douglas fir, hydrated lime, from 1/2 to 1/3 of the volume of cement, is added; if a hardwood sawdust is used, it is first treated by boiling with ferrous sulphate as described in Specification 560,801. The proportions of cement, sand and sawdust in the mix are between 1:1:2 to 1:2:1 by volume, preferably 1:1:2 to 1:1 1/2 :1/ba1/2 . In mixing, water is added in amount approximately equal to 40-45 per cent of the weight of cement plus 150 per cent of the weight of sawdust. If the composition is to be laid on a concrete foundation, the surface is cleaned, hacked and brushed to remove the surface skin and, if space is available, a cement-sand screed is applied; alternatively, a cement slurry is brushed into the concrete. The composition is laid immediately on to the screed or slurry. For application to a wooden floor, wire netting is first stapled down. After hardening and drying, the composition is wax polished or impregnated with linseed oil and white spirit, and different surface textures can be obtained by buffing.</p> |
