掺乙烯基可再分散聚合物水泥水化的交流阻抗研究

Study on Hydration Process of Cement Paste with Redispersible Vinyl Copolymer(CPP) by AC Impedance Spectroscopy

采用交流阻抗谱测试方法研究了掺乙烯基可再分散聚合物水泥浆体的水化进程,结果表明,纯水泥浆体正常的电化学反应在其水化9 h时已开始,而掺乙烯基可再分散聚合物水泥浆体正常的电化学反应则在其水化3 d时才开始,相应的交流阻抗谱曲线为准Randles曲线.孔溶液电阻Rs、电化学反应电阻Rct以及分形维数值Ds等交流阻抗参数的分析表明,乙烯基可再分散聚合物对水泥水化进程具有一定的延缓阻抑作用;在水化14 d时,掺乙烯基可再分散聚合物水泥浆体孔结构已基本稳定;相对于纯水泥浆体,掺乙烯基可再分散聚合物水泥浆体的孔形貌更简单、均匀,也更趋于三维体.

The hydration processes of cement pastes with CPP were studied by AC impedance spectroscopy. The results show that with its hydration degree developing, the electrochemistry reaction of pure cement paste begins at curing for 9 h, whereas the electrochemistry reaction of cement paste with CPP begins at curing for 3 d, with its AC impedance spectra being typical quasi-Randles curve. Resistance of pore solution（Rs）, resistance of electrochemistry reaction（Rct） and value of fractal dimension（Ds） indicate that CPP retards the hydration process of cement paste to some extent,pore structure of cement paste with CPP stabilizes after curing for 14 d and tends to three-dimensional structure which is much simpler than that of pure cement paste.