| 摘要 |
<p>Quick-setting concrete made from modified portland cement contains (a) water-soluble aliphatic polyhydroxy cpd. (I), which may contain COOH gps. in form of water soluble salts, and (b) a water-soluble resin (II) based on amino-striazine (III), modified by an aliphatic amino acid (IV), esp. glycine, in the form of a water soluble salt. The mole ratio HCHO: (II):(IV) is 1.5-6:1:0.15-1, pref. 3-4:1:0.3-0.7. The concrete can also contain standard plasticisers and air-pore generating agents. Pref. (I) is 0.05-0.5 wt.% on the cement, esp. 0.10.4% (as free acid) of a gluconate salt or is sorbital. (II) is pref. 0.01-2, esp. 0.05-0.8 wt.%. Addition of (II) delays the setting time. By appropriate choice of (I) and (II) the setting time, strength and flow properties can be adjusted to suit a particular end-use.</p> |
