人工煤气管道内壁腐蚀分析及防腐措施

分析了煤气管道内壁局部腐蚀的机理和原因,煤气管道的内应力和煤气中的杂质是造成煤气管道腐蚀的主要原因,其中硫化氢是造成电化学腐蚀的重要杂质。针对产生腐蚀的原因给出了防腐措施。     

酸性介质环境下结构受弯构件的腐蚀试验

酸性介质环境对钢筋混凝土结构具有较强的腐蚀作用 ,长期作用下 ,结构的可靠性将由于结构的腐蚀损伤而降低 ,目前尚无针对结构构件的腐蚀试验。针对酸性环境下钢筋混凝土受弯构件进行了整体腐蚀试验研究 ,通过钢筋电位、线性极化电阻的量测对构件的整体受腐蚀性能进行了定量研究 ,为受腐蚀钢筋混凝土结构耐久性分析提供理论依据     

热水采暖系统腐蚀与防止问题的研讨

本文系统介绍了热水采暖系统的腐蚀问题,对腐蚀种类和机理进行了系统说明,并针对系统的O2腐蚀、CO2腐蚀和垢下腐蚀的防治提出了解决办法。     

多元热流体腐蚀监测装置研制与应用评价

腐蚀是制约多元热流体技术推广应用的关键因素。采用高温缓蚀剂后,防腐效果良好,但未获取现场腐蚀速率。针对此,研制了腐蚀监测装置,将两个P110钢挂片置于多元热流体注热管线中,现场实施多元热流体热采,10天平均腐蚀速率为0.090 5mm/a,为均匀腐蚀,腐蚀产物主要是Fe2O3,验证了缓蚀剂防腐效果良好,满足目前多元热流热采防腐要求。     

混凝土结构硫酸盐腐蚀研究综述

硫酸盐腐蚀是影响混凝土结构耐久性能一种重要的化学劣化因子。系统地阐述了混凝土结构硫酸盐腐蚀的研究现状,总结了已有的研究成果,并针对混凝土结构硫酸盐腐蚀耐久性研究领域提出了需要继续研究和深入的若干问题。     

某500kV变电站地网腐蚀及改造措施研究

为找出某500 k V变电站地网腐蚀断裂原因,通过X射线物相分析了地网腐蚀产物和降阻剂成分,对变电站地网周围土壤和降阻剂进行了理化分析和腐蚀电化学试验。分析试验结果得出,地网腐蚀的主要原因是降阻剂腐蚀和硫酸盐还原菌腐蚀。针对腐蚀原因提出了改造措施:更换被腐蚀地网同时清除地网周围降阻剂,在较易发生腐蚀的集中接地装置周围及新换地网与旧地网连接处施加环保高效膨润土防腐剂。     

钢筋混凝土结构腐蚀疲劳研究现状与发展

针对钢筋混凝土结构在腐蚀环境下承受疲劳荷载发生腐蚀疲劳的现象,分析介绍了近几年钢筋混凝土腐蚀疲劳的研究现状,并提出了进一步需要研究的问题,以避免或减慢腐蚀疲劳的破坏。     

桩基在腐蚀环境中的承载力规律

在腐蚀环境中,桩基的承载力规律一向是国内和国外关注的焦点,氯盐、硫酸盐、碳酸盐、碳酸氢盐等造成的钢筋锈蚀是混凝土桩基性能劣化的关键原因。文章针对大海和临海腐蚀环境与内陆咸水湖和盐碱地腐蚀环境中,地下桩基的承载力规律,简要介绍了在腐蚀情况下桩基的承载力分类,总结和归纳了当前的研究现状。     

火力发电厂停(备)用热力设备的腐蚀与防护

电力设备的停用腐蚀严重影响机组的安全稳定运行。对停用腐蚀的机理及腐蚀的影响因素进行了分析,阐述了停用腐蚀防护的重要性及必要性,并针对各热力设备提出来相应的停用保护措施。     

电厂炉水品质与炉管的中性盐腐蚀

阐述了火电厂炉水品质对炉管产生中性盐腐蚀的影响,详细分析了引起中性盐腐蚀的原因,针对不同的情况提出了减轻炉管中性盐腐蚀的方法.     

预应力锚固结构腐蚀介质作用下的耐久性 试验研究

 基于对预应力锚固结构腐蚀影响因素的分析,选取pH值、时间、应力水平及材质作为影响预应力锚固结构腐蚀的主要因素进行分析,并对各因素正交组合后进行预应力杆件的室内加速腐蚀试验。得到预应力锚固结构在腐蚀介质作用下的外观规律性表现,并分析影响预应力锚固结构腐蚀的各种因素对于单位长度腐蚀量及断面损失率等指标的影响规律。试验结果表明,随pH值的增大,单位长度腐蚀量呈现出递减趋势,总体呈负指数形式发展;而随着时间的延长,腐蚀量不断增加,但腐蚀量增量逐渐减小,呈幂函数形式发展,而应力水平对于单位长度腐蚀量的影响并不显著。所得到的拟合公式能够正确地反映单位长度腐蚀量与各因素之间的关系,也为工程中预应力锚固结构使用寿命的预测奠定了理论基础。     

Performance evaluation of rebar in chloride contaminated concrete by corrosion rate

The presence of chloride ions in reinforced concrete (RC) plays a major role in reinforcement corrosion and hence for the durability and service life of RC structures. With growing concern towards the deterioration of reinforced concrete structures, the use of electrochemical techniques for their performance evaluation has become an important topic of durability study. This paper illustrates the findings of an experimental investigation carried out on large number of specimens for evaluating the performance of different types of rebar in chloride contaminated concrete made with different types of cement through different corrosion rate techniques. The specimens were prepared with three types of cement and three types of steel. From the results of corrosion rate, it was observed that the values of corrosion rate obtained by linear polarization resistance (LPR) technique with guard ring arrangement were in close agreement with those obtained by gravimetric method. On the other hand the corrosion rate values obtained by AC impedance spectroscopy were slightly lower than those obtained by LPR measurement. Further, correlations between different corrosion rate techniques were also obtained. From the results of analysis of variance (ANOVA), it was observed that chloride content has the strongest effect on corrosion rate as compared to other factors.     

高温下钢筋混凝土的锈蚀研究

描述了两种不同材料所作的钢筋混凝土(养护时间为28d)放在60℃高温的NaCl溶液中,外加12v的恒压电源,在实验结束这段时间内观察两种钢筋混凝土的锈蚀情况并用钢筋锈蚀仪测量两种混凝土的电位走势从而判断其锈蚀程度。结果表明温度对钢筋锈蚀速度有很大的影响,总体上看,透水混凝土锈蚀程度比普通混凝土要大。     

坑蚀对钢筋混凝土梁抗弯承载力的影响

比较了均匀锈蚀和坑蚀对锈蚀钢筋混凝土梁抗弯承载力的影响,定义了描述钢筋均匀锈蚀和坑蚀的两种参数。用试验数据比较了两种参数和锈蚀钢筋混凝土梁剩余抗弯承载力的关系,指出仅仅用均匀锈蚀描述锈蚀钢筋混凝土梁的抗弯承载力是不够的,还应考虑坑蚀的影响。研究了不同坑蚀系数下均匀锈蚀率和坑蚀锈蚀率的关系,指出确定钢筋坑蚀量的关键在于确定坑蚀系数的值,对坑蚀系数的选取应当慎重。给出了同时考虑协同工作系数和坑蚀系数的锈蚀钢筋混凝土梁抗弯承载力的计算公式,公式的计算结果与14根梁的试验结果可以很好吻合,表明所提出的公式可用于既有混凝土梁剩余抗弯承载力的评估。     

混凝土中钢筋通电加速锈蚀与自然锈蚀的对比

通电加速锈蚀是目前试验研究中用于获得锈蚀钢筋混凝土构件的一种常用方法,它与自然锈蚀之间存在一定的相关性和差异性,在系统归纳总结现有研究成果的基础上,从锈蚀机理、锈蚀过程、锈蚀速率、电通量等方面对两种锈蚀条件的相关性和差异性进行了细致的对比研究,对现有加速锈蚀试验研究成果的应用具有促进作用。     

氯盐环境自密实混凝土钢筋腐蚀速率试验

主要研究外渗氯盐侵蚀下的钢筋腐蚀,对比普通混凝土和自密实混凝土内钢筋的腐蚀电流密度时变曲线,对两种混凝土试件中钢筋的腐蚀速率进行分析和研究.试验结果表明:自密实混凝土内钢筋的腐蚀比较迟缓,初始的腐蚀速率较小,但最大腐蚀速率和总体腐蚀规律都与普通混凝土内钢筋基本一致.     

Sulfate attack and reinforcement corrosion in plain and blended cements exposed to sulfate environments

The extensive use and addition of mineral admixtures and the recent modifications in the physicochemical characteristics of portland cements have introduced a large number of variables that need to be addressed. Furthermore, the effect of cations associated with sulfate ions on these variables is inconclusive and extensively debated in the literature. On the other hand, the exposure of many reinforced concrete structures to sulfate-bearing environments has brought attention to the role of sulfate ions in the corrosion of reinforcing steel. Unfortunately, there is very little data on this aspect. The following subjects are addressed: (i) the effect of sulfate cation type on strength and expansion; (ii) the role of sulfate ions in reinforcement corrosion; (iii) the role of plain and blended cements in both sulfate attack and reinforcement corrosion; and (iv) a comparison of the performance of concrete made with the above-cited cements with that of small (25 mm cube) cube mortar specimens.     

Reliability of corroded thin walled pipes repaired with composite overwrap

Current design codes provide two design methods: allowable stress/strain design and limit state design. Design in the current pipework composite repair codes is based on the allowable design method and only two safety factors are applied to the ultimate strain of the composite layer and to the yield stress of steel. On the other hand, safety factors are applied to each of the load and resistance parameters in the limit state design method. The limit state design method is probabilistic based in which the safety factors are calibrated based on a target reliability index. In this study, an investigation into the reliability of rehabilitated pipelines is conducted. The limit state function is defined based on ASME PCC-2, and reliability analysis is conducted using the AFOSM method. Results show that ASME PCC-2 generally provides adequate safety although the level of safety is not uniform for different percentages of corrosion. Comparing the achieved results and the ISO 2394 target reliability indices, some resistance factors are proposed.     

油田采出水处理系统用药剂进展

2012年3月20日,北京城建勘测设计研究院院长马海志、副院长高文新赴安哥拉参加中信建设第十次高层会,并视察和指导安哥拉分院工作。在高层会前夕,院长马海志和副院长高文新受到了中央政治局委员、北京市委书记刘淇的亲切接见。刘淇书记对我院在北京地铁建设上的贡献给予充分肯定,并希望我院继续在非洲市场上续写辉煌的篇章。     

钢筋混凝土和钢纤维混凝土杂散电流腐蚀实验研究

依据地铁杂散电流对地下金属物质发生阳极氧化的电化学腐蚀机理,模拟了钢筋混凝土和钢纤维混凝土试件的杂散电流腐蚀实验。通过两种不同材料在相同的杂散电流环境中进行模拟腐蚀比较,分析了钢筋混凝土和钢纤维混凝土在抵制杂散电流腐蚀的耐久性和破坏形式方面的异同。结果表明,两种材料的耐久性能差异较大,破坏形式也不同,相同条件下,钢纤维混凝土的耐久性能显著降低。