【作者】 陈建伟；

【导师】 肖仪清； 丁铸；

【作者基本信息】 哈尔滨工业大学 ， 结构工程， 2008， 硕士

【摘要】 利用电化学脱盐法能够有效去除钢筋混凝土中的氯离子,电化学脱盐技术作为一种较为新颖的技术,国内外虽然做了大量的研究,但是还不够系统深入。本文通过研究影响电化学脱盐效率的几种因素,建立电化学脱盐的数学模型,从而对电化学脱盐技术更加深入的了解;通过研究电化学脱盐技术对钢筋混凝土材料力学特性,微观结构,电化学特性等的影响,为实际工程更科学的使用电化学脱盐技术,提供理论依据。本文的研究内容主要包括以下几个方面:1)通过自行设计的电化学脱盐装置研究了不同水灰比、不同电流密度在不同脱盐周期下对电化学脱盐效率的影响。研究结果表明:在电化学脱盐的前六周,随着脱盐时间的增加,混凝土中氯离子含量基本程线性递减,实际工程中可以通过延长脱盐时间来达到电化学脱盐的目的;水灰比对电化学脱盐有显著影响,水灰比提高,混凝土的密实度降低,电化学脱盐效率提高;电流密度高,混凝土中离子传输的能垒高,电化学脱盐效率高。2)通过对电化学脱盐前后钢筋混凝土材料的抗压强度试验和拉拔试验,研究发现:电化学脱盐对钢筋混凝土材料抗压性能影响不大,但是随着脱盐周期的增加,钢筋和混凝土之间的粘结性能降低;利用液氮吸附法测量脱盐前后混凝土内孔隙结构的变化。研究发现:电化学脱盐技术改变了混凝土材料内部的孔隙特征。3)通过测量脱盐前后钢筋半电池电位变化和交流阻抗谱试验,研究发现:经过脱盐处理钢筋的电位正移,电化学脱盐处理的试件有明显的特征阻抗谱出现,说明电化学脱盐技术有使活化钢筋逐渐恢复钝化的趋势。4)通过研究电化学脱盐的影响因素,得出不同水灰比,电流密度混凝土中氯离子含量随时间变化关系,研究钢筋和混凝土之间的粘结机理,得出钢筋和混凝土材料之间的粘结强度和脱盐周期之间的关系,为实际工程中估算脱盐电流、脱盐周期等提供理论根据。更多还原

【Abstract】 As a kind of novel technology, electrochemical chloride extraction technology can remove chloride ions in the concrete effectively. The scholars around the world have done lots of work, however, the research are still not thorough enough. Several factors on efficiency of electrochemical chloride extraction are compared, by establishing the mathematical model, electrochemical chloride extraction technology could be comprehended more thorough. By researching influence of electrochemical chloride extraction technology on mechanics characteristic, microscopic structure, electrochemistry characteristic of reinforced concrete materials, more scientific use about electrochemical chloride extraction technology can be offered to the actual project. The main works of this paper include:Firstly, the influence on efficiency of electrochemical chloride extraction due to the different water ratio, the different current density under the different desalinization cycle has been studied by the instrument we designed ourselves. The results indicated that: at the previous six weeks when the chloride ion content in the concretes decreased linearity as desalinization time’s increased, in the actual project, electrochemical chloride extraction may be served by extending desalinization time; The water ratio has the remarkable influence on the electrochemistry desalinization, the water ratio enhances as concretes compactness reduces, thus the electrochemistry desalinization efficiency could be enhanced; Also, the higher current density is, the larger concretes intermediate ion transmission’s energy barrier, which can result in the high electrochemistry desalinization efficiency.Secondly, according to the compressive strength of reinforced concrete material during the electrochemistry, and strength change between the steel bar and the concretes, utilizing the liquid nitrogen adsorption law to test the pore structure change, the results indicated that: the electrochemistry desalts has little effect on the reinforced concrete material resistant to compression performance, however, along with desalinization cycle increases, the concretes bonding properties between the steel bar and concrete reduces; the pore structure can be changed due to the electrochemical chloride extraction technology, and which results in the change on some performance of reinforced concrete materials.Thirdly, by the half-cell potential method and the alternating-current impedance spectrum experiment,we can discovered that: the electrochemistry desalinization processing test sample showed the obvious characteristic impedance spectrum after the desalinization the electric potential to move,which can explained that the electrochemistry desalinization technology could activate the steel bar to resume deactivated gradually.Finally, the mathematical model which is affected by the different factor can be obtained by researching theses factors and the total equation which based on the different influencing factor is obtained, more scientific use about electrochemical chloride extraction technology can be offered to the actual project.更多还原