一种减缩型无碱液体速凝剂的制备及性能评价

采用丙烯酸、聚乙二醇单甲醚和甲基丙烯酸甲酯,通过酯化和聚合反应合成聚丙烯酸盐类减缩剂,再将合成减缩剂与硫酸铝、二乙醇胺等混合,通过有机-无机化合反应,合成一种减缩型无碱液体速凝剂,并对其性能进行测试。结果表明,当该减缩型无碱速凝剂的折固掺量为4.1%时,水泥净浆凝结时间和水泥砂浆强度符合GB/T 35159—2017《喷射混凝土用速凝剂》要求,且与其它水泥的适应性较好;该减缩型无碱速凝剂折固掺量为基准水泥用量的0.26%时,可大幅度减小基准水泥砂浆试件的干缩。

Preparation and performance evaluation on a shrinkage-reducing alkali-free liquid accelerator admixture

A polyacrylic acid salt was prepared by esterifying and polymerizing with acrylic acid,polyethylene glycol monomethyl ether and methyl methacrylate,and thena shrinkage-reducing alkali-free liquid accelerator admixture was produced by organic and inorganic reactions by mixing with the shrinkage reducing agent,aluminum sulfate,diethanolamine,etc. And its properties were tested. The results show that using the benchmark cement test,the shrinkage-reducing alkali-free liquid accelerator admixture is consistent with the requirements of standard GB/T 35159—2017 "Flash setting admixtures for shotcrete" and has good adaptability with other cement when the translated solid content was 4.1%. At the same time,the shrinkage-reducing alkali-free liquid accelerator admixture can greatly reduce the dry shrinkage of mortar when the translated solid content was 0.26% of benchmark cement consumption.