摘要 |
A mixture comprised of an alkali metal carbonate and an inorganic salt of ferric iron, other than ferric phosphate, is an accelerator for cementitious compositions and is particularly useful for shotcrete and hand-applied mortar. The preferred alkali metal carbonates are sodium carbonate and potassium carbonate and the preferred ferric iron salts are ferric sulfate, ferric chloride and ferric nitrate. The mixture achieves initial set times of at most about 3 minutes and final set times of at most about 10 minutes. Both initial and final set times are shorter than predicted by simply averaging the corresponding set times of both components when used alone.
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