| 摘要 |
<p>The binder contains by wt. 72-82% fly ash obtd. from hard coal; plus 16-24% hydraulic binder; and 2-4% gypsum. The pref. binder is clinker, cement, or hydraulic lime; and the mixt. may also contain 4-6% silica sand. They flay ash and possibly sand are pref. first milled to a Blaine fineness (BF) of min. 4000 cm2/g, esp. to ca. 5000 cm2/g; and are then milled with the other materials at l000-8000 cm2/g, esp. to ca. 7000 cm2/g. The pref. concrete made using the binder employs a ratio of 1 pt. of the above binder: 1 pt. normal fine sand: 0.29 pts. water; or 1 pt. binder: 2 pts. coarse sand: 0.29 pts. water. The concrete mouldings may also be heat treated. A high proportion of inexpensive fly ash, obtd. from thermal power stations, can be used without loss of strength of the concrete, which has virtually no tendency to swell, shrink, or creep, and has high resistance to frost.</p> |
