离子导电砂浆的研发及性能研究

发布时间：2018-07-10 02:17

本文选题：离子导电砂浆 + 电阻率　；参考：《广州大学》2017年硕士论文

【摘要】：传统导电混凝土以钢纤维、钢渣、石墨等作为导电相材料,此类材料依靠电子的定向移动而导电,制作时存在导电材料聚团,易生锈等缺点。与传统导电混凝土不同,离子导电砂浆试件是基于溶液离子在外加电场作用下定向移动而导电的原理制作的,其制作工艺简单,原材料廉价易得,不会受到聚团和生锈等问题的困扰。由于离子导电砂浆试件的导电机理与传统导电混凝土的导电机理不同,本文选择了不同的电解质溶液(CuSO4溶液和FeSO4溶液)和电极材料制作离子导电砂浆试件,对其导电性的影响因素开展了研究,并结合宏观试验与微观试验的结果,对离子导电砂浆的配合比、施工工艺和构造形式提出了优化措施。影响离子导电砂浆试件导电性的基本因素主要有电解质溶液的浓度和电解质的种类,试件孔隙率,电极种类等。其中,试件孔隙率主要受外加剂种类、掺量、水灰比、龄期等因素的影响,较大的孔隙率可以有效提高渗透效率。本文选择铝粉作为外加剂加入水泥砂浆试件以提高试件孔隙率,并对不同养护龄期与水灰比的试件进行了渗透试验和微观试验,试验结果表明,随着龄期的增加,试件内部的孔隙会被钙矾石等水化产物逐渐占据。当水灰比较大时,砂浆流动性较好,砂浆内部形成孔径大小均匀的毛细连通孔。因此,本文提出制备离子导电砂浆试件的最优方案是养护龄期28d且水灰比为0.7。影响离子导电砂浆的另一基本因素为电解质溶液的种类与浓度,本文选择了 CuSO4溶液和FeS04溶液作为导电材料制作离子导电砂浆试件,试验结果表明,由于不同的电解质溶液浓度存在不同的溶解度,因此也存在不同的最优浓度范围,试件水灰比为0.5时,CuSO4溶液最优浓度为2.91%～3.85%, FeSO4溶液最优浓度为9.91%～10.71%。在此范围内,制备离子导电砂浆试件时渗透效率高,制得的试件导电性能好。本文也选择了镀锌铁网和铜网作为电极制备离子导电砂浆试件,试验结果表明应选用交换电流密度大的电极,可以有效缓解极化效应;不应选择能直接与电解质溶液发生化学反应的电极。试件总龄期(含养护时间和养护期满后的时间)会对离子导电砂浆试件导电性产生较大影响。随着龄期的增加试件内部水分逐渐消耗和蒸发,电解质溶液浓度改变,甚至析出,堵塞孔隙,从而影响试件的导电性。为减少水分蒸发的不利影响,本文提出将环氧树脂辊涂在导电砂浆试件表面,试验结果表明辊涂环氧树脂的试件电阻率远远小于没涂环氧树脂的试件。为了进一步保证离子导电砂浆导电性能的稳定性,本文提出一种可使离子导电砂浆自动补充电解质溶液的构造措施,试验结果表明,该构造可以有效的保证离子导电砂浆电阻率的稳定性。
[Abstract]:Traditional conductive concrete uses steel fiber, steel slag, graphite and so on as conductive phase materials. This kind of materials rely on the directional movement of electrons to conduct electricity, and there are some shortcomings in making conductive materials such as conglomeration of conductive materials, easy to rust and so on. Unlike conventional conductive concrete, ionic conductive mortar specimens are made on the basis of the principle of directional moving and conducting of solution ions under the action of an external electric field. The fabrication process is simple, and the raw materials are cheap and easy to obtain. Will not be agglomeration and rust and other problems. Because the conductive mechanism of ionic conductive mortar specimen is different from that of traditional conductive concrete, different electrolyte solutions (CuSO4 solution and FeSO4 solution) and electrode material are selected to make ionic conductive mortar specimen. Based on the results of macroscopic and microscopic tests, the optimization measures for the mix ratio, construction technology and construction form of ionic conductive mortar are put forward. The main factors affecting the conductivity of ionic conductive mortar are the concentration of electrolyte solution, the type of electrolyte, the porosity of the sample, the type of electrode, and so on. Among them, the porosity of the specimen is mainly affected by the kinds of admixture, the amount of admixture, the ratio of water to cement, the age and so on, and the larger porosity can effectively improve the permeability efficiency. In this paper, aluminum powder was used as admixture to increase the porosity of cement mortar. The permeation test and microcosmic test were carried out on the specimens with different curing age and water-cement ratio. The results showed that the porosity of the specimens increased with the increase of age. The pores in the specimen will be gradually occupied by hydration products such as ettringite. When the water ash is large, the fluidity of mortar is better, and the capillary connected holes with uniform pore size are formed inside the mortar. Therefore, the optimal scheme for the preparation of ionic conductive mortar specimens is that the curing age is 28 days and the water-cement ratio is 0.7. Another basic factor affecting ionic conductive mortar is the kind and concentration of electrolyte solution. CuSO4 solution and FeS04 solution are selected as conductive materials to make ionic conductive mortar. The experimental results show that CuSO4 solution and FeS04 solution are used as conductive materials to make ionic conductive mortar. Because different electrolyte solutions have different solubility, so there are different optimal concentration ranges. The optimum concentration of CuSO4 solution is 2.91% and 3.85% when the water-cement ratio is 0.5, and the optimum concentration of FeSO _ 4 solution is 9.91% ~ 10.71%. In this range, the ionic conductive mortar has high permeability and good conductivity. This paper also selected galvanized iron mesh and copper net as electrodes to prepare ionic conductive mortar. The results show that the electrode with high exchange current density can effectively alleviate the polarization effect. Electrodes that can react directly with electrolyte solutions should not be selected. The total age (including curing time and curing time after expiration) will have a great influence on the conductivity of ionic conductive mortar. With the increase of age, the internal water consumption and evaporation, the concentration of electrolyte solution change, even precipitate, clogging the pores, thus affecting the conductivity of the specimen. In order to reduce the adverse effect of water evaporation, the epoxy resin roll is coated on the surface of conductive mortar. The results show that the resistivity of the sample coated with epoxy resin is much lower than that of the specimen without epoxy resin. In order to further ensure the stability of ionic conductive mortar, this paper presents a construction measure which can automatically replenish electrolyte solution of ionic conductive mortar. This structure can effectively guarantee the stability of ionic conductive mortar resistivity.
【学位授予单位】：广州大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU578.1

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