干湿两用型粉状无碱速凝剂的制备与性能研究

Research on synthesis and properties of powder alkali-free accelerator for dry and wet shotcrete

以超细硫酸铝、氟硅酸镁、固体醇胺等为原料,制备了一种干、湿两用型粉状无碱速凝剂,同时研究了该速凝剂的匀质性、低温稳定性,以及与不同水泥的适应性。结果表明:该速凝剂的稳定性良好,低温条件下仍能保持较好的状态。既可以作干粉速凝剂使用,也可以加水溶解后作为液体速凝剂使用;相同折固掺量下,将干粉速凝剂加水溶解用作液体速凝剂时,砂浆的抗压强度略高于掺粉状速凝剂的砂浆,但均符合GB/T 35159—2017《喷射混凝土用速凝剂》对无碱速凝剂的相关要求,且对不同水泥具有良好的适应性。

A kind of powder alkali-free accelerator for dry and wet shotcrete was prepared by using aluminum sulfate,magnesium fluorosilicate,solid alkyl amine as raw materials.The homogenization,stability at low temperature and adaptability to different cements were studied.The results show that the accelerator has good stability and remained in good condition at low temperature.It not only can be used as a dry powder accelerator,but also be used as a liquid accelerator after being dissolved in water.Under the same solid content,when the dry powder accelerator is dissolved in water and used as a liquid accelerator,the compressive strength of mortar is slightly higher than that of powder,but it can meet the relevant requirements of alkali-free accelerator in GB/T 35159—2017"Flash setting admixtures for shotcrete".Similarly,the accelerator has a wide range of adaptability to different cements.