摘要 |
<p>Lightwt. foamed concrete is produced as follows: (i) a foamed slurry (a) is moulded, (ii) an intermediate half-cured article (20-60cm in thickness) is produced by keeping the increase in temp. inside the mould article 30 deg.C lower than the temp. of (i), (iii) the intermediate article is cured to obtain the foamed concrete. The foamed slurry (a) contains 0.75 pts.wt. water per 1 pt.wt. solid component and is prepd. at 45-80 deg.C. (a) comprises, as solid components, cement (20-40 wt.%), lime (5-15 wt.%), silica (40-60 wt.%) and plaster (3-10 wt.%). At least 50 wt.% of the lime must be slaked (pref. 80-95%). While the intermediate half-cured moulded article, which is 50-130cm thick, is cured, the increase in the thickness of the mould is controlled to 5% or lower. The difference in density between the upper and lower parts of the obtd. foamed concrete is 0.04 g/cm3 or less. The starting material can contain other additives e.g. colouring agent, waterproofing agents, etc.</p> |