| 摘要 |
PURPOSE: A cement mineral(calcium aluminate)-based accelerator for the dry and the wet process shotcrete that is mainly used in construction of tunnel, dam and underground structure is provided to improve compression strength, reduce environmental pollution and save construction cost. CONSTITUTION: The cement mineral-based accelerator comprises 50-90pts.wt. of amorphous calcium aluminate powder, 4-30pts.wt. of Na2CO3, 0.1-20pts.wt. of anhydrous gypsum, and optionally 0.1-10pts.wt. of sodium aluminate(NaAlO2), 0.1-20pts.wt. of slaked lime(Ca(OH)2) and 0.1-0.5pts.wt. of carboxylated styrene butadiene as a thickener, wherein the amorphous calcium aluminate powder is prepared by mixing CaO with Al2O3 to be C12A7, melting at 1600-1700deg.C, and spraying with high-pressure air to make less than 10mm of particles.
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