Impedance measurements on an engineered cementitious composite: A critical evaluation of testing protocols
Impedance measurements on an engineered cementitious composite: A critical evaluation of testing protocols
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DOI：
10.1016/j.measurement.2018.07.066
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发表时间：
2018-12
期刊：
影响因子：
5.6
通讯作者：
B. Suryanto;Hideaki Takaoka;W. J. McCater;D. Saraireh;H. Taha
中科院分区：
文献类型：
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作者：
B. Suryanto;Hideaki Takaoka;W. J. McCater;D. Saraireh;H. Taha
传统上采用端到端（两点）电测量技术来评估硬化水泥材料的体电阻率。通过使用具有四种不同尺寸（即，尺寸）的立方体样本研究工程水泥复合材料（ECC）的电阻抗，对该测试方法进行了严格的评估。 50毫米、70毫米、100毫米和150毫米。在目前的工作中，通过放置在每个样本相对面的两个外部板电极在 1Hz-10MHz 频率范围内测量 ECC 样本的阻抗响应（以奈奎斯特图的形式）。插入板/样本界面之间的导电凝胶或饱和合成海绵用作电极-样本接触介质。结果表明，海绵接触介质引入了寄生响应，该响应在整个频率范围内均可检测到，并且在电极接触面积较小的样本和接触表面上存在空气空隙的样本中尤其明显。当使用导电凝胶或浸有高导电液体的海绵时，这种效应会大大降低。还表明，从奈奎斯特图确定的材料的真实体电阻率可以通过从存在海绵的 ECC 体电阻率中减去海绵本身的电阻率来评估。还对具有嵌入式电极布置的样本进行了基准研究。
An end-to-end(two-point) electrical measurement technique is traditionally employed in evaluating the bulk resistivity of hardened cementitious materials. This testing methodology is critically evaluated by studying the electrical impedance of an engineered cementitious composite (ECC), using cuboidal specimens with four different dimensions viz. 50 mm, 70 mm, 100 mm and 150 mm. In the present work, the impedance response (in the form of Nyquist plots) of the ECC specimens was measured over the frequency range 1 Hz–10 MHz via two external plate-electrodes placed at opposite faces of each specimen. A conductive gel, or saturated, synthetic sponges inserted between the plate/specimen interface were used as the electrode-specimen contacting medium. It is shown that the sponge contacting medium introduced a spurious response which was detectable across the entire frequency range and was particularly evident in specimens with smaller electrode contact area and in specimens with air-voids present on the contact surface. This effect was considerably reduced when either the conductive gel or sponges saturated with highly-conductive liquid was used. It is also shown that the true bulk resistivity of the material, identified from the Nyquist plot, can be evaluated by subtracting the resistivity of the sponge itself from the bulk resistivity of the ECC with the sponges present. Benchmarking studies were also undertaken on specimens with an embedded electrode arrangement.