Na/Al对赤泥-煤系偏高岭土地聚合物电化学响应的影响  

Effects of Na/Al on Electrochemical Responses of Polymers in Red Mud-coal Metakaolin Geopolymer

作　　者：武涛 刘剑平[1] 李贝宁 何斌[1,2] 白晓红[1] WU Tao;LIU Jian-ping;LI Bei-ning;HE Bin;BAI Xiao-hong(Civil Engineering College,Taiyuan University of Technology,Taiyuan 030024,China;State Key Laboratory of Geotechnical Engineering,Wuhan Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China)

机构地区：[1]太原理工大学土木工程学院,太原030024 [2]中国科学院武汉岩土力学研究所岩土力学与工程国家重点实验室,武汉430071

出　　处：《科学技术与工程》2020年第28期11740-11745,共6页Science Technology and Engineering

基　　金：国家自然科学基金(51879180,41807256);岩土力学与工程国家重点实验室资助课题(Z017003);河海大学岩土力学与堤坝工程国家教育部实验室开放基金(201702)。

摘　　要：对养护28 d龄期不同Na/Al条件下的赤泥-煤系偏高岭土地聚合物的单轴抗压强度和电化学阻抗响应进行了系列测试和分析。根据地聚合物中离子扩散的特点,建立了基本等效电路模型,利用ZSimDemo3.30d软件拟合与解析等效电路,分析各电路元件参数与Na/Al的关系。结果表明,赤泥-煤系偏高岭土地聚合物的抗压强度随着Na/Al的增大呈先增大后减小的趋势。电化学阻抗谱测试结果显示,Nyquist图均呈现高频区扁平容抗弧和低频区不明显的扩散曲线;等效电路模型为R[Q(RW)],且随着Na/Al的增大,地聚合物体系的总电阻和硅铝酸盐凝胶中的双电层电容均呈先增大后减小的趋势,而电荷转移电阻随着Na/Al的增大呈减小趋势。运用电化学阻抗谱技术对地聚合物的电化学阻抗特征进行分析,揭示了赤泥-煤系偏高岭土地聚合物抗压强度随Na/Al的变化规律,同时也证明了电化学阻抗谱技术运用于地聚合物强度测试的可行性,为地聚合物无损检测技术提供新思路、新手段。The uniaxial compressive strength and electrochemical impedance response of red mud-coal metakaolin with different Na/Al at a conservation age of 28 days were tested and analyzed in series.Based on the characteristics of ion diffusion within the geopolymer,a basic equivalent circuit model was established,and the equivalent circuit was fitted and analyzed by ZSimDemo3.30d software.The relationship between the parameters of each circuit element and Na/Al was analyzed.The results reveal that the compressive strength of the red mud-coal metakaolin geopolymer increases first and then decreases with the increase of Na/Al.The results of the electrochemical impedance spectroscopy test show that all the Nyquist diagrams demonstrate a flat capacitive reactance arc in the high frequency region and an insignificant diffusion curve in the low frequency region,and the equivalent circuit model is R[Q(RW)].As Na/Al increases,both the total resistance of the geopolymer system and the electric double layer capacitance in the aluminosilicate gel increase first and then decrease,while the charge transfer resistance decreases.By the electrochemical impedance spectroscopy,this study reveals the changes in the compressive strength of red mud-coal kaolin geopolymers with Na/Al,proves the feasibility of electrochemical impedance spectroscopy applying to the geopolymer testing and analysis process.The electrochemical impedance spectroscopy provides a new idea and method for non-destructive testing of geopolymers.

关 键 词：地聚合物 电化学阻抗谱 等效电路 抗压强度 

分 类 号：TU599[建筑科学—建筑技术科学]