基于EIS的NMK水泥浆早期水化特性分析  

Analysis on early hydration characteristics of cement paste containing NMK based on EIS

作　　者：范颖芳 赵宇龙 李秋超 Fan Yingfang;Zhao Yulong;Li Qiuchao(College of Transportation Engineering,Dalian Maritime University,Dalian 116026,China)

机构地区：[1]大连海事大学交通运输工程学院,大连116026

出　　处：《东南大学学报（自然科学版）》2024年第6期1447-1455,共9页Journal of Southeast University：Natural Science Edition

基　　金：国家自然科学基金资助项目(51578099)。

摘　　要：为了研究纳米偏高岭土(NMK)对水泥浆早期水化性能的影响,考虑5种NMK掺量(0、1%、3%、5%、7%),利用电化学阻抗谱试验研究NMK水泥浆水化早期(48 h内)水化进程,对比分析5种NMK水泥浆早期水化过程中电化学参数的演变规律.基于阻容串联电路,考虑弥散效应和电极/浆体界面双层电容,建立NMK水泥浆水化早期等效电路模型R_(1)(Q_(1)R_(2))Q_(2),基于介电常数描述NMK水泥早期水化进程.结果表明:NMK延迟水泥浆阻抗谱负电容消失时间,增强了铝酸钙相反应,促进水泥早期水化;所建立的NMK水泥浆水化早期等效电路模型计算结果与试验结果吻合较好;利用等效电路模型得到的NMK水泥浆孔溶电阻与标准稠度用水量呈线性关系,与流动度呈指数关系;利用介电常数曲线能够很好地描述NMK水泥浆早期水化过程.To investigate the effect of nano-metakaolin(NMK)on the early hydration characteristics of cement paste,the electrochemical impedance spectroscopy(EIS)test was executed on the cement pastes containing NMK particles at the early hydration stage(within 48 h).Five NMK contents(0,1%,3%,5%,7%)were used to replace ordinary cement.The evolution of electrochemical parameters during the early hydration process of five types of NMK cement paste was compared and analyzed.An equivalent circuit model R_(1)(Q_(1)R_(2))Q_(2),based on a capacitance series circuit,was established to consider both the dispersion effect and double capacitance at the electrode/paste interface.In addition,dielectric constant was employed to characterize the early hydration process of NMK cement paste.The results show that NMK delays the negative capacitance loss time,enhances calcium aluminate reaction,and promotes the early hydration of cement paste.The calculated results by the provided equivalent circuit model show in good agreement with the experimental results.The pore resistance obtained by the equivalent circuit model presents a linear relation with standard consistency water content,while it takes an exponential relation with fluidity.The dielectric constant curve can be used to identify the early hydration process of NMK cement paste.

关 键 词：纳米偏高岭土 水泥浆 早期水化 电化学阻抗谱 介电常数 

分 类 号：TU528.1[建筑科学—建筑技术科学]