渗透性有机硅表面防护涂料的研究及应用现状

阐述了混凝土的腐蚀机理和工程中得到广泛应用的渗透性有机硅涂料的防护机理;并对水性、溶剂型和乳液型三种有机硅防护涂料的作用原理和使用性能及其研究状况、市售产品和性能检测标准进行了介绍。     

水性无机富锌涂料的防腐性能研究

无机富锌涂料具有杰出的耐侵蚀性能、耐溶剂性、耐辐射性、耐热性,在恶劣腐蚀环境下是用于钢结构件的最佳涂料之一。选取了几种具有代表性的水性无机富锌涂料进行研究,通过测试涂层的渗水性、抗盐雾性能、电化学保护性能,深入分析并比较了这几种水性无机富锌涂料防腐性能的优劣性。实验结果表明：GZH202型与FZ-1型无机富锌涂料具有较好的防腐性能,而LW-1型和IC531型水性无机富锌涂料的防腐性能相对较差。实验结果为进一步研究水性无机富锌涂料的使用提供了很好的参考价值。     

丙烯酸基水性金属防腐蚀涂料的研究与应用进展

金属的腐蚀防护有机涂层逐渐向更加环保的水性化发展趋势,改性丙烯酸基水性防腐蚀涂料具有耐腐蚀、耐老化、耐化学介质等特点,在防腐蚀涂料领域有着较为广泛的应用.从高分子链结构和引入新材料复合改性乳液两个角度较为系统地综述了水性丙烯酸树脂改性方法及机理,并简要介绍了改性水性丙烯酸防腐蚀涂料的应用进展.     

工业烟囱防腐蚀案例

1冶炼厂钢烟囱、钢筋混凝土烟囱防腐蚀 某有色金属冶炼厂钢烟囱内部和钢筋混凝土烟囱外部,用TD-P-I和TD-P-Ⅱ型耐高温无机涂料防腐蚀,这两种涂料均以磷酸铝溶液为成膜物质,加入耐酸腐蚀的金属氧化物或氢氧化物粉末及其它添加物组成.     

水性无机富锌涂料的应用研究

为了减少金属的腐蚀给人们带来的巨大损失,研究一种水性无机富锌涂料,通过与各种防腐涂料在防腐性能、安全性能以及施工性能等方面进行比较可知:水性无机富锌涂料不仅具有优良的防腐性能,方便施工,而且不易引起火灾,同时对环境没有任何污染,满足人们对环境保护的要求.水性无机富锌涂料的环保性成为目前具发展前途的环保型涂料.水性无机富锌涂料将会得到更为广泛的应用.综述了水性无机富锌涂料的成膜机理、防腐机理、类型、优越性及其在施工过程中的要求等,同时对其发展进行了展望.     

电化学方法判断混凝土中钢筋腐蚀的临界状态

采用自行设计制造的人工模拟气候大型试验箱,研究钢筋混凝土结构在模拟海洋环境中的腐蚀情况。采用自腐蚀电位、线性极化以及电化学阻抗谱等方法综合研究了标准养护14天的普通硅酸盐混凝土试样置于试验箱中钢筋腐蚀的临界状态判断标准。结果表明,当混凝土中钢筋表面的氯离子浓度达到诱导钢筋腐蚀的临界浓度时,自腐蚀电流密度会有数量级的突增,线性极化法和电化学阻抗谱法均能用来准确判断这一临界腐蚀状态。     

模数对水性硅酸钾富锌涂层电化学行为的影响

通过测量涂层腐蚀电位与涂层电化学交流阻抗,研究了水溶性K2SiO3溶液的模数(SiO2/K2O摩尔比)对水性无机富锌涂层电化学行为的影响.结果表明,水性无机富锌涂料随着水基模数的增加,涂层腐蚀电位增高,涂层对腐蚀介质的屏蔽性能增强,涂层中锌粉颗粒的活性溶解阻力增大.用扫描电子显微镜(SEM)观测不同模数水性无机富锌涂层的结构表明,水性无机富锌涂料水基模数的增加使涂层中锌粉颗粒之间充分交联,涂膜强度增大,涂层中锌粉颗粒之间的缝隙减小,涂层的致密性增强.     

聚脲聚氨酯环氧涂料用於混凝土钢筋防腐蚀的研究

聚脲聚氨酯环氧涂料用於混凝土钢筋防腐蚀的研究林薇薇（浙江大学高分子系杭州３１００２７）钢筋混凝土建筑物耐久性下降的主要原因之一是增强钢筋的腐蚀。因为混凝土是多孔性凝胶体，空气中的氧、湿气和其它腐蚀介质能通过孔隙和细裂缝侵蚀钢筋，而钢筋变成铁锈时体积要...     

深水港建设涂料防护设计

深水港建设结构材料防护采用涂料涂料，钢结构及钢管桩可借鉴大桥及码头钢桩防护的成功数据，钢筋混凝土管桩作为码头桩使用，不可忽视海水介质对混凝土结构的腐蚀问题。本文对管桩焊接口防护，借助海底埋管防护技术，结合涂料特点，实施薄弱环节的双重防护。     

保护混凝土表面的硅酮乳液

硅酮树脂涂料覆盖层能有效保护混凝土设施，以及抵抗物理，化学和微生物的破坏作用。本文对硅酮树脂，水性的砖石防水硅酮的性能进行了介绍。     

混凝土保护涂层抗氯离子渗透性研究

在NaCl溶液中对混凝土保护涂层进行干/湿循环加速腐蚀实验,用电化学循环极化法和高压渗水法对混凝土保护涂层的防护效果进行了研究,并将两种方法研究结果进行对比.结果表明：氯盐环境中,混凝土保护涂层可以有效提高混凝土的抗渗性,降低氯盐对钢筋的腐蚀破坏;循环极化测试法可用于研究钢筋钝化膜的溶解特性和钢筋的锈蚀趋势.      

Damage analysis and cracking model of reinforced concrete structures with rebar corrosion

The damage of concrete cover in reinforced concrete structures induced by reinforcing steel corrosion is investigated in this study. The damage process of the concrete cover can be divided into two distinct stages: the non-cracking stage and the partial cracking stage. An analytical model based on damage mechanics and elastic mechanics is developed to predict the concrete cracking due to steel corrosion. Based on this model, the expansive pressure and the radial loss of steel bar are discussed. Parametric studies are carried out to examine the effects of the correlative factors on the expansive pressure and the steel loss.     

NO_2~-和Cl~-对模拟混凝土孔隙液中钢筋腐蚀行为的影响

应用极化曲线法和电化学阻抗技术研究了NO_2~-和Cl~-对钢筋在不同pH值的模拟混凝土孔隙液中的腐蚀行为,结果表明,钢筋耐蚀性与溶液的pH值,以及NO_2~-和Cl~-的浓度相关,pH值的降低和Cl~-浓度的增高都会使钢筋的耐蚀性降低。在含Cl~-的模拟液中,随着NO_2~-浓度升高,钢筋腐蚀速率降低,在pH值为12.50和10.50的溶液中,当[NO_2~-]/[Cl~-]≥0.4时,NO_2~-对钢筋具有良好的阻锈作用。     

Shear performance of reinforced concrete beams with corroded stirrups in chloride environment

Experiments were conducted for the investigation of the influence of reinforcing steel corrosion on the shear capacity of reinforced concrete beams. The shear performance of RC beams with different corrosion levels in both longitudinal reinforcing steel bars and stirrups was examined. Relationships of corrosion-induced crack widths in concrete cover with the corrosion level of the reinforcing steel bars were obtained. Engineering approaches were developed to predict the residual shear strength of the corroded beams.     

停建工程中钢筋混凝土的保护

对停,缓建工程的混凝土钢筋预留部位及进场钢材若不及时采取有效的防护措施,将使裸露钢筋因自然环境尤其是冻融而遭受腐蚀,减小截面并降低混凝土对钢筋的握裹力,还会使混凝土产生裂缝,降低结构整体寿命,采取有效的措施对钢筋混凝土进行保护,实践表明效果较好。     

Corrosion of Carbon Steel and Corrosion-Resistant Rebars in Concrete Structures Under Chloride Ion Attack

Corrosion of reinforced concrete is the most challenging durability problem that threatens reinforced concrete structures, especially structures that are subject to severe environmental conditions (i.e., highway bridges, marine structures, etc.). Corrosion of reinforcing steel leads to cracking and spalling of the concrete cover and billions of dollars are spent every year on repairing such damaged structures. New types of reinforcements have been developed to avoid these high-cost repairs. Thus, it is important to study the corrosion behavior of these new types of reinforcements and compare them to the traditional carbon steel reinforcements. This study aimed at characterizing the corrosion behavior of three competing reinforcing steels; conventional carbon steel, micro-composite steel (MMFX-2) and 316LN stainless steel, through experiments in carbonated and non-carbonated concrete exposed to chloride-laden environments. Synthetic pore water solutions have been used to simulate both cases of sound and carbonated concrete under chloride ions attack. A three-electrode corrosion cell is used for determining the corrosion characteristics and rates. Multiple electrochemical techniques were applied using a Gamry PC4? potentiostat manufactured by Gamry Instruments (Warminster, PA). DC corrosion measurements were applied on samples subjected to fixed chloride concentration in the solution.     

Effect of electrode orientation on linear polarisation measurements using sensor controlled guard ring

Abstract

Use of a sensor controlled guard ring has been developed in recent years to enhance the accuracy of linear polarisation corrosion rate measurements on reinforced concrete structures. The sensors are used to monitor potential differences measured on the concrete surface above the reinforcing steel. These data are then used to confine the corrosion measurement to a known area of reinforcing steel. The role of the sensors is paramount in maintaining adequate confinement of the perturbation applied to the reinforcing steel. Experiments were conducted on reinforced concrete specimens containing both active and passive zones of reinforcing steel. Polarisation resistance measurements were taken using both a potentiostatically controlled guard ring device developed at the University of Liverpool and a galvanostatically controlled commercial device. Both devices indicated that the orientation of the sensor electrodes can affect the polarisation resistance determined when taking measurements on passive steel next to actively corroding areas. The sensor orientation was not observed to affect the polarisation resistance measurements taken on actively corroding steel next to passive steel.     

RTM成型技术在码头钢筋混凝土结构修复中的应用

采用树脂传递模塑工艺Resin Transfer Molding(RTM)对上海石化热电总厂煤码头钢筋混凝土结构进行填充修复和防腐蚀处理。分析了钢筋混凝土材料的腐蚀以及RTM成型工艺的关键因素:钢筋混凝土的失效主要是由于Cl-渗入混凝土内部而导致钢筋材料发生电化学腐蚀,而树脂料对增强材料浸润能力以及铺设技术对RTM成型工艺都有直接的影响。通过RTM成型对受损码头进行填充修复,明显提高了结构承载和改善其外观。     

Einflußgrößen der Fremdkathoden aus Bewehrungsstahl in Beton auf die Erdbodenkorrosion von Stahl

Factors influencing the activity of reinforcing steel as cathode on the soil corrosion of steel Factors influencing the corrosion cell established between steel/soil (anode) and reinforcing steel in concrete (cathode) were investigated in field tests extending up to 3 years. In all cases, the differences between the corrosion rates measured in the cell and under free corrosion conditions were higher than the equivalent cell current. This effect means an increase of the cathodic partial reaction by cell action (negative difference effect), and is related to better protecting layers in the case of free corrosion. As to the cathodes, the parameters of the concrete have nearly no effect. But galvanizing of the reinforcing steel has a strong influence on the cell action. Since the cell resistance is mainly controlled by the electrolyte resistance (ground resistance of the anodes) the changes in the polarization resistance of the cathodes can hardly influence the cell action. A decrease of cell currents due to galvanizing the reinforced steel is no doubt present, but the effect is too poor for proper protection against cell activities. Therefore, only conventional electrochemical methods or organic coatings on the reinforcing steel can be applied as protective measures.     

丙烯酸系乳胶用于钢筋混凝土的防腐蚀研究

用电化学阻抗谱研究了丙烯酸系乳胶作为混凝土添加剂或钢筋表面涂层时对钢筋腐蚀行为的影响,加速腐蚀试验结果表明混凝土中添加乳胶后能够延缓钢筋表面钝化层的破坏,而对混凝土的渗透性能影响不大,乳胶涂层能够显著减小钢筋腐蚀速率,涂层的存在改变了钢筋表面的腐蚀状态,在此基础上提出了改善钢筋混凝土抗蚀能力的措施。