CONCRETE MIX Russian patent published in 1998 - IPC

FIELD: production of building materials; production of structures from heavy concrete based on high-calcium fly ash resulting from combustion of lignite. SUBSTANCE: traditionally, proposed concrete mix comprises high-calcium fly ash, crushed stone, sand, chloride-containing additive and water. Inventive novelty resides in fact that proposed concrete mix employs fly ash having free calcium oxide content 20-32.2%, sand in which fraction of grains having size below 0.16 mm accounts for 10-18%, and also in which soluble active silica content is 4-6.5%. As said chloride- containing additive, method employs calcium chloride, said components being taken in following weight ratio, wt.%: high-calcium fly ash 12-16; crushed stone 42-52; sand of above-specified quality 26-34; calcium chloride 0.16-0.24, water being balance. To produce proposed concrete mix, fly ash, crushed stone, calcium chloride and 40-60% mixing water are charged into forcible-action, rotary-type concrete mixer and subjected therein to pre-treatment for 180-240 sec., followed by adding sand and remaining amount of mixing water and by additionally stirring mix components for 50-60 sec. EFFECT: 1) high-quality concrete is produced; 2) fly ash causing serious problems for environment, is here utilized and gives profit. 2 tbl