硬化混凝土试块中有机阻锈剂阻锈性能的研究

IMR OpenIR

	硬化混凝土试块中有机阻锈剂阻锈性能的研究
	郑雷刚
学位类型	硕士
导师	杨怀玉
	2010
学位授予单位	中国科学院金属研究所
学位授予地点	北京
学位专业	腐蚀科学与防护
关键词	阻锈剂钢筋混凝土电化学技术氯离子侵蚀
摘要	"混凝土中钢筋的腐蚀是导致钢筋混凝土结构性能退化和过早破坏的主要因素，混凝土中钢筋的腐蚀与防护成为亟待解决的关键技术之一。在混凝土结构浇筑过程中添加阻锈剂，以其防护效果好、操作简便和成本低廉的特点，在国内外已得到广泛地应用。然而，传统阻锈剂因其毒性和可能造成的环境污染，以及对混凝土力学性能的影响，已不能满足当前工程建设和环保的需要。开发高效、环保阻锈剂技术已成为当今阻锈剂发展的一种趋势。本文以有机醇和醇胺类化合物为基础，研制了几种纯有机阻锈剂配方，借助腐蚀电化学测量技术，在饱和NaCl溶液长期浸泡和干湿交替循环实验条件下，通过测量硬化混凝土试块中钢筋电极的腐蚀电位 (Ecorr) 和宏观腐蚀电流密度 (Icorr)，以及电化学交流阻抗(EIS) 行为，研究了阻锈剂对碳钢电极腐蚀行为的影响及其长期阻锈效果，并对其阻锈机理进行了初步分析、探讨。主要结论如下： (1) 以有机醇和胺为主体，研究制备了多种添加型醇胺基有机钢筋阻锈剂，利用电化学测量手段，对其长期阻锈性能进行了研究。 (2) 长期浸泡实验结果表明，在浸泡初期，空白和添加Ca(NO2)2阻锈剂混凝土试块中的钢筋电极可保持钝态，但随浸泡时间的延长，钢筋电极Ecorr 和Rct开始下降，Icorr 和Cdl增大；在浸泡100天后，添加Ca(NO2)2后的电化学行为与空白样相近，Ca(NO2)2的阻锈效果明显降低。 (3)对添加阻锈剂CI-5和CI-6的混凝土试块，在浸泡的前50天内，钢筋电极可保持钝态，而后钢筋电极Ecorr 和界面电阻开始下降，Icorr 和界面电容增加，110天后趋于稳定，表现出一定的阻锈效果；而添加阻锈剂CI-1和CI-2的样品，钢筋电极在浸泡的前100天内始终处于钝态，而后电化学行为开始发生变化，可延长钢筋开始腐蚀时间1倍以上，对钢筋锈蚀显示出良好的防护效果；对于阻锈剂CI-3、CI-4，在整个浸泡实验的250天内，钢筋电极的腐蚀电化学行为变化缓和，钢筋基本处于钝态，可明显延长钢筋的起始锈蚀时间，表现优良的阻锈剂性能。6种阻锈剂的优劣顺序为：CI-4＞CI-3＞CI-2＞CI-1＞CI-5＞CI-6。 (4) 干湿循环腐蚀实验结果表明，随循环周次的增加，空白试样中钢筋电极的电位逐步降低，腐蚀电流密度逐渐增加；而添加阻锈剂的钢筋电极Ecorr 随时间延长呈上升趋势，Icorr 逐渐下降，表明阻锈剂具有良好的阻锈效果。关键词：阻锈剂; 钢筋混凝土; 电化学技术; 氯离子侵蚀"
其他摘要	"The corrosion of steel rebar embedded in concrete is the main cause for the premature failure of reinforced concrete structures and became of great issues need to be resolved in the world-wide. The addition of corrosion inhibitors is an effective and efficient method due to its lower cost and easy application. Recently, the environment-friendly organic inhibitors have been paid more attentions. In the present paper, some amine-alcohol based inhibitors were prepared and their long-term inhibition performance for steel rebar inside mortar specimens immersed in saturated NaCl solutions were examined by half cell potential (Ecorr), macrocell current density (Icorr) measurements and electrochemical impendence technique, as well as wet-dry cycles corrosion test was also conducted. The inhibition mechanism of the inhibitors was brief discussed on the basis the competitive adsorption of inhibitor molecules with Cl- on steel rebar surface. The main conclusions can be deduced as follows: (1) 6 amine-alcohol based inhibitors were formulated on the basis of organic compounds containing OH- and -NH2 functional groups and their long-term inhibition properties were investigated using electrochemical measurements. (2) Based on the results of long term immersion experiments, it can be concluded that at the initial immersion stage, the steel electrodes were kept in passive state either for uninhibited system or inhibited ones. However，the Ecorr and R values of electrodes in blank and inhibited mortar samples with Ca(NO2)2 sharply decreased when the immersion time reached 50 days, while Icorr and CCPE remarkably increased. The Ca(NO2)2 exhibited the limited inhibition effect. (3) Considering specimens with amine-alcohol based inhibitors, the electrodes were in the passive state in the initial immersion 100 days for the inhibitor CI-1and CI-2, and 250 days for CI-3 and CI-4. These indicate that the corrosion of steel rebar was effectively delayed and the initiation corrosion time of steel was prolonged 1~2 times in comparison with that in blank system. The inhibition sequence is in the order of: CI-4＞CI-3＞CI-2＞CI-1＞CI-5＞CI-6. (4) The results of wet-dry cycles corrosion test showed that the electrode Ecorr gradually increased and Icorr decreased with increasing of wet-dry cycles time, on the contrary, Ecorr gradually decreased and Icorr increased for the blank mortar specimens. These suggest that the inhibitors exhibited a good effectiveness. Keywords: Corrosion inhibitors; Reinforced concrete; Electrochemical techniques; Chloride-induced corrosion."
文献类型	学位论文
条目标识符	http://ir.imr.ac.cn/handle/321006/64229
专题	中国科学院金属研究所
推荐引用方式 GB/T 7714	郑雷刚. 硬化混凝土试块中有机阻锈剂阻锈性能的研究[D]. 北京. 中国科学院金属研究所,2010.