新型喷射混凝土用无碱液体速凝剂的研制与优化配伍

Development and Optimizing-mixing of New-type Non-alkaline Liquid Accelerator of Shotcrete

介绍了新型喷射混凝土用无碱液体速凝剂的研制与优化方法,采用无机、有机物质复合的研制路线,使用硫酸盐和中性钠盐作为主要促凝物质,并利用高分子物质对速凝剂进行优化,如使用醇胺类聚合物提高砂浆的1 d强度,使用酰胺类聚合物来改善喷射混凝土的粘聚性,以提高喷射混凝土与基体的粘结力,降低喷射过程中的回弹损失量。优化后的无碱液体速凝剂完全满足《喷射混凝土用速凝剂》标准(JC477-2005)中的一等品要求,使水泥在3min内初凝,8 min内终凝,砂浆1 d强度大于12 MPa,与空白砂浆试块相比28 d抗压强度比达94%以上,后期强度基本无损失,性能优于国内外同类品牌。且原料成本低廉,仅为1000元/t左右,工业化生产方法简单,适合工业化大批量生产。

A method was introduced to develop and optimize a new-type non-alkaline liquid accelerator of shotcretc. It adopted composites of inorganic and organic materials and used sulphate and neutral sodium salt as main accelerated materials, polymers as optimization materials. For example, it used alcamines polymer to increase 1 d strength of mortar, and used amide polymer to improve concrete adhesive performance so as to improve the bonding strength of concrete and matrix, meanwhile to decrease the rebound lost in shooting process. The optimized accelerator completely meets the requirements for the first class products in the Flash Setting Admixtures ofShoterete standard（JC477 -2005）, which can let the initial setting time within 3 minutes and the final setting time within 8 minutes. 1 d strength of mortar is beyond 12 MPa and comparing with blank mortar specimens, 28 d strength ratio is more than 94%, and there is no loss in later strength basically. The results show that this accelerator has better performance than the similar fa- mous brand products, its raw materials＇ cost is very cheap just 1000RMB/t and the simple industrialized producing method is suitable for mass production.