| 摘要 |
<p>Lightweight construction matl. pref. comprises 360g. silica sand, 75g cement 680, 75g milled quick lime, 0.2 dm3 water, 0.25 dm3 foaming agent and 0.5 anhyd. powdered aluminium. The finely milled silica sand is mixed with the cement and quick lime substantially dry then water at >=30 degrees C is added and mixing is continued. The foaming agent which may comprise a mixt. of Cu(NO3)2 and sodium auryl sulphate or a commercial foaming agent such as "Foacem" (RTM) is added and the batch is then transferred to a high speed mixer where the Al powder is added and then the mortar is cast into moulds. After ageing under 12 atmos. of satd. water vapour at 220 degrees C, light weight blocks of 0.45 kg/dm3 which are dimensionally stable and shock resistant are produced which can be worked with woodworking tools.</p> |
