新型复合阻锈剂对钢筋混凝土阻锈性能影响的研究

发布时间：2018-10-13 17:44

【摘要】：混凝土结构耐久性问题是当今建筑行业内最关注问题之一，影响着国家和社会的可持续发展，其中，钢筋锈蚀是导致钢筋混凝土结构耐久性劣化的主要问题之一，造成了国家重大经济损失。因此，研究一种阻止钢筋锈蚀的关键措施变得尤为重要。研究显示，钢筋阻锈剂是防止钢筋锈蚀的最有效方法之一，并且正在不断被研究和开发，尤其是环保型的有机阻锈剂。但是，多数阻锈剂的研究主要集中于混凝土模拟孔溶液中，对其在混凝土中的阻锈研究，，特别是应用电化学方法实时监测钢筋锈蚀的研究不多。因此，本课题目的是研制一种新型的复合阻锈剂，并分别在模拟孔溶液和混凝土中研究其阻锈的性能与效果。首先，基于前人的研究基础上选取了阻锈效果最佳的一种醇胺类阻锈剂，即N, N-二甲基乙醇胺（DMEA），并利用电化学方法及其参数表征了该阻锈剂在混凝土模拟孔溶液中的最佳阻锈浓度范围，改变单氟磷酸钠（MFP）的量，利用相同的方法，得到两种阻锈剂最佳阻锈效果下的比值。其次，研究了最佳比值下复合阻锈剂在混凝土模拟孔溶液中的临界氯离子含量，其阻锈效果与商品阻锈剂NaNO2和Sika901进行了对比，研究表明：研制的复合阻锈剂在NaCl质量分数为3%~4%时，对钢筋的阻锈效果明显；氯盐掺量为3.5%时，复合阻锈剂的阻锈效果优于商品阻锈剂NaNO2和Sika901。基于混凝土模拟孔溶液得到的复合阻锈剂比值，将该种复合阻锈剂内掺于混凝土中，监测了混凝土中钢筋电化学参数（自腐蚀电位法、极化电阻、交流阻抗谱)的变化情况，以此方法研究了不同掺量的复合阻锈剂和不同种类阻锈剂阻锈效果的对比；并固定复合阻锈剂的掺量，研究了水灰比和矿物掺合料对混凝土中钢筋锈蚀状态的影响。另外，通过电化学拟合软件，经过与实测值的对比，确立了混凝土中钢筋锈蚀过程的等效电路图，并分析了混凝土中钢筋交流阻抗的整体特征。研究表明：低水灰比中，阻锈剂的阻锈效果表现明显；高水灰比中，阻锈效果表现不明显。最后研究了碳化和碳化与电加速氯盐耦合作用下，内掺阻锈剂的混凝土中钢筋的抗氯离子研究。研究表明：在7d和14d时，复合阻锈剂均提高钢筋的抗碳化能力；在耦合作用下，掺阻锈剂的混凝土抵抗腐蚀的能力明显提高，复合阻锈剂的阻锈效果优于Sika901。
[Abstract]:The durability of concrete structures is one of the most concerned problems in the construction industry today, which affects the sustainable development of the country and society. Among them, the corrosion of steel bars is one of the main problems leading to the deterioration of durability of reinforced concrete structures. Caused great economic losses to the country. Therefore, it is particularly important to study a key measure to prevent the corrosion of steel bars. The research shows that the corrosion inhibitor of steel bar is one of the most effective methods to prevent the corrosion of steel bar, and is being researched and developed continuously, especially the organic corrosion inhibitor of environmental protection. However, most of the corrosion inhibitors are mainly concentrated in the simulated pore solution of concrete, especially the research of corrosion inhibition in concrete, especially the application of electrochemical method to real-time monitoring the corrosion of steel bars. Therefore, the purpose of this paper is to develop a new compound rust inhibitor, and to study its performance and effect in simulated pore solution and concrete respectively. First of all, based on the previous studies, a kind of alkanolamine rust inhibitor was selected, which has the best effect on rust inhibition. That is, N, N-dimethylethanolamine (DMEA),) was used to characterize the optimum corrosion inhibition concentration range of the rust inhibitor in concrete simulated pore solution by electrochemical method and its parameters. The amount of sodium monofluorophosphate (MFP) was changed, and the same method was used. The optimum ratio of two antirust agents was obtained. Secondly, the critical chlorine ion content of the composite rust inhibitor in the simulated pore solution of concrete was studied under the optimum ratio, and the rust inhibition effect was compared with that of the commercial antirust agents NaNO2 and Sika901. The results show that when the mass fraction of NaCl is 3 ~ 4, the corrosion inhibition effect of the composite rust inhibitor is obvious, and the corrosion inhibition effect of the compound rust inhibitor is better than that of the commercial NaNO2 and Sika901. when the chlorine salt content is 3.5. Based on the ratio of composite corrosion inhibitor obtained from simulated pore solution of concrete, the composite corrosion inhibitor was mixed in concrete to monitor the change of electrochemical parameters (self-corrosion potential method, polarization resistance, AC impedance spectrum) of steel bar in concrete. In this paper, the effects of different amount of composite rust inhibitor and different kind of corrosion inhibitor on the corrosion state of steel bar in concrete were studied, and the effects of water cement ratio and mineral admixture on the corrosion state of steel bar were studied. In addition, the equivalent circuit diagram of the corrosion process of steel bar in concrete is established by comparing the measured values with the electrochemical fitting software, and the integral characteristics of AC impedance of steel bar in concrete are analyzed. The results show that in the low water-cement ratio, the rust inhibition effect of the antirust agent is obvious, but the rust inhibition effect is not obvious in the high water-cement ratio. Finally, the chloride ion resistance of concrete reinforced with corrosion inhibitor was studied under the coupling of carbonation and carbonation with electroaccelerated chloride. The results show that the anti-carbonation ability of steel bar is improved by the composite rust inhibitor at 7 and 14 days, and the corrosion resistance of concrete mixed with rust inhibitor is obviously improved, and the corrosion inhibition effect of the composite rust inhibitor is better than that of Sika901..
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU375

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