为解决因预制混凝土早期强度不足导致的模板周转率偏低的问题，同时保障混凝土的工作性能与耐久性，开发了一种适用于免蒸养轨枕混凝土的早强型聚羧酸减水剂，通过正交试验确定了基础合成工艺参数，并选用7种不同早强单体进行母液合成。结果表明，基础合成工艺参数为引发剂与聚醚单体摩尔比0.35，双氧水与抗坏血酸摩尔比5，链转移剂与聚醚单体摩尔比0.2，反应温度50℃，掺0.23%采用季铵类阳离子早强单体合成减水剂混凝土的1、3、7 d抗压强度分别为33.1、48.0、58.9 MPa；掺0.23%采用带有酰胺基团的早强单体合成减水剂混凝土的1、3、7 d抗压强度分别为30.6、47.6、58.5 MPa。

An early strength polycarboxylate superplasticizer suitable for non-steam conditioned sleeper concrete was developed to solve the problem of low formwork turnover rate caused by insufficient strength of precast concrete in the early stage,while ensuring the workability and durability of concrete. Through orthogonal test,the basic process parameters were determined,and seven different monomers were selected to synthesize the mother liquor. The results showed that the basic synthesis process parameters were as follows:molar ratio of initiator to polyether monomer was 0.35,molar ratio of hydrogen peroxide to ascorbic acid was 5,molar ratio of chain transfer agent to polyether monomer was 0.2,reaction temperature was 50 ℃,and when 0.23% of the superplasticizer synthesized using quaternary ammonium cationic methylacryloyloxyethyl trimethyl ammonium chloride was added,the 1-day,3-day,and 7-day compressive strengths of the concrete were 33.1 MPa,48.0 MPa,and 58.9 MPa,respectively;when 0.23% of the superplasticizer synthesized using N,N'-dimethylacrylamide with amide groups was added,the 1-day,3-day,and 7-day compressive strengths of the concrete were 30.6 MPa,47.6 MPa,and 58.5 MPa,respectively.