用交流阻抗方法研究碱激发矿渣水泥浆体水化和微观结构

发布时间：2018-03-30 20:13

本文选题：碱激发矿渣水泥　切入点：交流阻抗　出处：《湖南大学》2015年硕士论文

【摘要】：碱激发胶凝材料具有降低环境影响,减小温室效应以及降低能源消耗的优势,是重要的生态型水泥品种,前景十分广阔。同时,水泥基体材料的交流阻抗特性与微观结构有着密切的关系,利用交流阻抗方法来研究水泥基体材料的孔隙率、孔结构和孔溶液可以得到非常可靠和准确的结果,该方法可望发展成为一种灵敏的无损结构测试方法。因此,可以利用非破损的交流阻抗方法对碱激发矿渣水泥浆体系水化特性进行更深入的研究,促进碱激发矿渣水泥的应用。本研究主要围绕水玻璃模数和碱掺量对碱激发矿渣水泥水化过程中交流阻抗特性的影响展开,分析电路元件参数随水玻璃模数和碱掺量的变化规律。本次试验采用的水胶比为0.35,水玻璃模数为0、0.5、1.0和1.5,碱掺量按Na_2O的量占总胶凝材料质量的4%、6%和8%计算。在本研究采用的40Hz-35MHz频率范围内测试得到了较为完整的高频半圆弧,且高频半圆弧的直径随着水玻璃模数以及碱掺量的增加而不断减小,这一现象使得在硅酸盐水泥浆体系交流阻抗研究中得到的相关结论不能直接应用于碱激发体系。同时,本研究提出了一个与实测Nyquist图拟合较好的等效电路模型,其中R_1和R_3分别表示连通孔和非连通孔内导电路径的电阻,n2是与不导电固相内毛细孔有关的常相角指数,n3是与水化产物中凝胶孔有关的常相角指数。实验结果表明,R_1和R_3均随龄期的延长而增大,且在早期水化速率和孔溶液离子浓度的共同作用下,R_1随水玻璃模数和碱掺量的增加而减小。由于碱激发矿渣水泥内5-10nm凝胶孔体积随水玻璃模数和碱掺量的增大而不断增加,凝胶孔数量增多,基体结构复杂程度提高,使得R_3随0.5-1.5水玻璃模数和碱掺量的增加而增大。n2随水化龄期的延长而增大,随水玻璃模数和碱掺量的增加而减小。n2与交流阻抗测试得到的Nyqusit图偏转角有关,正确分离出Nyquist图中圆弧的组成,有助于对常相角指数的分析。n3在水化早期随龄期的延长而增大,之后基本保持在0.93-0.99之间不变,与0.5-1.5之间的水玻璃模数和4-8%的碱掺量无关,而水玻璃模数为0的矿渣水泥浆体n3则在0.72-0.75范围内基本不变。水玻璃和氢氧化钠激发的矿渣水泥浆体测试得到的n3存在差异,可能与不同激发剂激发得到的水化产物有关。0.5-1.5水玻璃模数激发的矿渣水泥,10-104nm范围内的孔对应的n2小于5-10nm范围内的孔对应的n3,且与碱掺量无关,而氢氧化钠激发的矿渣水泥n2和n3相差不大。
[Abstract]:Alkali activated cementitious materials can reduce the impact on the environment, reduce the greenhouse effect and reduce energy consumption advantages, is an important ecological cement varieties, the prospect is very broad. At the same time, the impedance characteristics of cement matrix material and micro structure has a close relationship with AC impedance method to study the cement base material porosity, pore structure and pore solution can be very reliable and accurate results, this method is expected to develop into a sensitive non-destructive testing method of structure. Therefore, using non-destructive method of AC impedance characteristics of hydration of alkali slag cement slurry system to stimulate further research, promote the application of alkali activated slag cement. This study focuses on the influence of modulus of water glass and alkali dosage to stimulate AC impedance characteristics of slag cement hydration process of alkali, water glass modulus analysis with circuit element parameters Changes and alkali dosage. This test adopts the water cement ratio is 0.35, the modulus of water glass is 0,0.5,1.0 and 1.5. The content of alkali by Na_2O of the total amount of cementitious material quality in 4%, 6% and 8% in the 40Hz-35MHz frequency range is calculated. The test used in this study were obtained in the high frequency arc is half complete, and high frequency arc diameter with the modulus of water glass and increase the content of alkali decreases. This phenomenon makes research on Portland cement slurry system impedance in the relevant conclusions can not be directly applied to the base excitation system. At the same time, this study proposes a Nyquist figure fitting well with the measured equivalent the circuit model, where R_1 and R_3 are respectively connected and non connected resistance hole hole conductive path, N2 is often associated with conductive solid phase index within the pores, N3 and hydration product in the gel pore constant phase angle index. The experimental results show that R_1 and R_3 were decreased with age increasing, and the interaction of the early hydration rate and ion concentration in pore solution under R_1, with the increase of the modulus of water glass and alkali dosage decreases. Because of alkali activated slag cement 5-10nm gel pore volume increases continuously with increasing the modulus of water glass and alkali dosage and gel pore number, matrix structure complexity, extend R_3 along with the increase of 0.5-1.5 modulus of water glass and alkali dosage increased.N2 with hydration time increases, with the increase of modulus of water glass and alkali dosage decreased by.N2 and AC impedance test Nyqusit the deflection angle, the correct separation of the composition of the circle in the Nyquist diagram, is helpful to the analysis of.N3 on the phase angle index in the early hydration increases with the age increasing, but remained unchanged between 0.93-0.99 and 0.5-1.5 between the water glass modulus Regardless of the content of alkali and 4-8%, and the modulus of water glass slag cement slurry for N3 0 is in the range of 0.72-0.75 was basically unchanged. The slag cement paste test of water glass and sodium hydroxide excited by N3 are different, may get the hydration products of.0.5-1.5 to stimulate the modulus of water glass slag cement with different exciting 10-104nm, within the scope of the hole corresponding to the N2 is less than 5-10nm within the scope of the hole corresponding to the N3, and has nothing to do with the content of alkali, sodium hydroxide and activated slag cement N2 and N3 had no obvious difference.

【学位授予单位】：湖南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU52

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