高保坍型聚羧酸减水剂的合成及性能表征

Research on synthesis and characterization of high slump retention superplasticizer

研制了一种高保坍型聚羧酸减水剂,可以在炎热环境下使用,具有减水率高、保坍性好等优势。通过PC-M与不同水泥的适应性研究、混凝土保坍性试验、吸附量以及Zeta电位的研究,结果表明:n(AA)∶n(T)=5∶1时,得到的聚羧酸减水剂PC-M性能最优;PC-M掺量为0.2%时,混凝土1 h坍落度保持率为97.8%;对于不同种类的水泥,吸附量是聚羧酸减水剂发挥分散作用的一个前提,但并不是吸附量越大对水泥的塑化效果越好;PC-M是以空间位阻而不是静电斥力为主要作用发挥其分散的特性。

A high slump retention superplasticizer with high water reduction and high slump retention is developed,which can be used in hot environment. This study investigated the adaptability between PC-M and different types of cement,concrete slump, adsorption and zeta potential. The results indicated that PC-M has the best performance at n（AA）：n （T）=5：1 ,when the PC-M con- tent is 0.2%, 1 h concrete slump retention rate is 97.8%. For different types of cement,the adsorption amount of polycarboxylate plays the role of a premise of dispersion, but not greater adsorption capacity, the better the plasticizing effect of the cement. PC-M plays the role of dispersion mainly on the basis of steric hindrance rather than electrostatic repulsion.