| 摘要 |
<p>Cement mixt. (I) comprises (a) a cement; (b) fly ash contg. 15-45 wt.% CaO; (c) an hydroxycarboxylic acid; and (d) a water-soluble source of alkali metal ions. An additive for cement mixts. contg. fly ash comprising an alkalimetal salt of hydroxycarboxylic acids or a mixt. of a hydroxycarboxylic acid with alkali metal carbonates, bicarbonates or hydroxides is also claimed. (b) contains 25-30 wt.% CaO. Molar ratio of alkali metal ions:hydroxycarboxylic acids is 0.5-1.5:1, pref. 0.6-1:1. (c) contains alkalimetalcarbonates, bicarbonates or hydroxides. (c) and (d) are present as alkali metal salts of a hydroxycarboxylic acid. (I) esp. contains 71-73% (b), 25-26% (a) and 2.5-3.5 salt, and opt. 60-80 wt.% sand. USE/ADVANTAGE - (I) is used as a concrete, mortar or casting mortar, in the building industry. (I) has high strength</p> |
