桥梁钢结构的大气腐蚀寿命预测

桥梁钢结构由于腐蚀造成的事故危及到桥梁的安全运行,腐蚀引起的灾难性事故屡见不鲜,特别是焊接钢结构和承受较大应力状况下的钢结构,由于在应力作用下,腐蚀将大大的加速。为了保证桥梁的安全运行,对存在一定程度腐蚀的钢构件开展寿命预测,根据预测结果来进行钢构件检测和维修的决策,是一项非常重要的工作。     

关于铁路桥规压挠构件总稳定性验算方法的最新讨论

在研究分析国内外有关桥梁钢结构现行设计规范的基础上,结合科研设计经验和我国铁路桥涵钢结构工程的实际情况,提出了应在修订中的我国《铁路桥涵钢结构设计规范》中增加双向受弯压挠构件总稳定性验算方法的建议．所提出的适用公式能与原桥规单向受弯压挠构件稳定性验算公式圆顺地衔接起来．     

基于氟涂料的桥梁钢结构腐蚀防护技术

我国的桥梁建设已经进入到一个良好的发展阶段,桥梁钢结构借助良好的性能常成为大跨径桥梁主跨桥。但是实际使用过程中由于各种因素的影响导致桥梁钢结构容易腐蚀,严重影响到桥梁的正常使用与安全。介于此,本文以解决桥梁钢结构腐蚀为核心,采用基于氟涂料的防护方式,在分析桥梁钢结构腐蚀机理的基础上提出具体的防护方案,旨在为实际海上桥梁工程钢结构的防腐工作提供有价值的参考。     

大气腐蚀环境下钢构件的可靠度

通过对钢结构构件腐蚀后可靠度的分析,提出了在役腐蚀钢结构抗力和荷载的计算模型,提出了在役腐蚀钢结构构件可靠度计算方法,从而为进一步的安全评估,确定钢结构使用寿命具有重要意义。     

浅议钢结构桥梁在我国的应用

概括了钢结构桥梁的优点及适用范围,综述了钢结构桥梁在我国的主要应用,并针对钢结构桥梁的腐蚀问题作了探讨,最后指出钢结构桥梁具有更广阔的应用空间。     

分形理论在钢结构腐蚀表面表征中的应用

采用分形理论研究钢结构腐蚀构件表面的表征方法,通过试验验证钢结构腐蚀构件表面的分形特征,用功率谱法计算出钢结构腐蚀构件表面分形维数,为在役钢结构安全性评定提供手段。     

浅析涂层在钢结构建筑中的应用

影响钢结构安全的因素很多,其中钢结构的稳定问题、钢材锈蚀以及钢结构耐火性差等问题成为影响安全的主要因素。文章结合工程实际,分析钢结构腐蚀防护的重要性,论述了钢结构建筑中钢构件的锈蚀机理,重点探讨了在设计中如何采用合理的方案避免刚才的腐蚀。介绍了钢结构防腐涂装的各项技术措施以及钢结构抗火设计理念和具体的防火措施以及钢结构防腐的方法及工艺,评价了各种方法的效果及注     

对现代桥梁钢结构防腐涂层体系设计探讨

在现代桥梁建造中,对桥梁钢结构必须进行防腐设计,以避免钢结构在所处的腐蚀环境中发生腐蚀破环。本文就桥梁钢结构所处的腐蚀环境为基础,简要介绍了桥梁钢结构防腐蚀图层体系设计的基本原则,及桥梁钢结构防腐蚀图层设计所用材料进行介绍,并在此基础上探讨了桥梁钢结构防腐蚀体系设计的选择。     

应力腐蚀对桥梁用钢磁记忆信号的影响机理研究

桥梁钢结构在近海大气环境下的应力腐蚀问题已引起众多关注,而金属磁记忆检测技术对钢构件缺陷检测的高效便捷性使其在腐蚀检测领域的应用成为可能.本文分析了应力对腐蚀及磁记忆信号的影响机理,建立了腐蚀和金属磁记忆检测之间的关系,揭示了运用金属磁记忆检测技术进行腐蚀区域定位的机理,为腐蚀定量检测和腐蚀区域反演提供了理论基础.     

多跨连续钢梁桥的时变地震易损性研究

针对以往建立易损性曲线过程中通常忽略结构多构件老化与退化对地震响应的潜在影响这一情况,本文对考虑多构件退化的桥梁时变地震易损性进行了研究。该方法主要研究钢筋混凝土桥梁暴露于劣化环境下的地震性能,分析了除冰盐中氯化物引起的钢筋混凝土圆柱和桥梁支座多构件腐蚀退化机理,着重考虑氧化产物导致混凝土保护层开裂下的混凝土退化与氯腐蚀导致的钢筋退化,桥梁多构件退化下的地震响应可通过三维非线性动力分析获得。此外,在建立时变易损性曲线过程中,基于蒙特卡洛仿真方法,综合考虑了氯离子扩散过程、地面运动以及材料参数的不确定性。对遭受氯化物侵蚀的某一多跨连续(MSC)钢梁桥进行非线性动力分析,数值结果表明,地震作用下若考虑时变腐蚀退化,桥梁构件和系统易损性曲线均会随着时间推移而发生相应的改变,失效概率增大;与单构件腐蚀退化的时变地震易损性曲线相比,考虑多构件退化的桥梁系统时变易损性更加保守,利于工程安全。对桥梁结构进行抗震性能评估时,以上结果验证了地震灾害和环境危害相结合的重要性。     

Corrosion damage assessment and monitoring of large steel space structures

Large steel space structures, when exposed to a harsh corrosive environment, are inevitably subjected to atmospheric corrosion and stress corrosion cracking. This paper proposes a framework for assessing the corrosion damage of large steel space structures subjected to both stress corrosion cracking and atmospheric corrosion. The empirical model for estimating atmospheric corrosion based on measured information is briefly introduced. The proposed framework is applied to a real large steel space structure built in the southern coastal area in China to assess its corrosion damage and investigate the effects of atmospheric corrosion on stress corrosion cracking. Based on the results, the conceptual design of the corrosion monitoring system of large steel space structures is finally conducted as the first step for a real corrosion monitoring system.     

Corrosion damage assessment and monitoring of large steel space structures

Large steel space structures, when exposed to a harsh corrosive environment, are inevitably subjected to atmospheric corrosion and stress corrosion cracking. This paper proposes a framework for assessing the corrosion damage of large steel space structures subjected to both stress corrosion cracking and atmospheric corrosion. The empirical model for estimating atmospheric corrosion based on measured information is briefly introduced. The proposed framework is applied to a real large steel space structure built in the southern coastal area in China to assess its corrosion damage and investigate the effects of atmospheric corrosion on stress corrosion cracking. Based on the results, the conceptual design of the corrosion monitoring system of large steel space structures is finally conducted as the first step for a real corrosion monitoring system.     

混凝土工程中钢筋腐蚀检测技术与评价

钢筋腐蚀是公认影响混凝土耐久性的最主要因素1。钢筋腐蚀检测和腐蚀状况判定可为钢筋混凝土结构的剩余载荷和结构耐久性提供基础数据。同时,混凝土中钢筋锈蚀的及时发现和准确诊断,是结构耐久性评定、剩余使用寿命预测的重要前提。本文简单介绍钢筋在结构中的腐蚀原理后,详细介绍了钢筋混凝土结构中钢筋锈蚀检测的几种检测方法,最后提出钢筋腐蚀检测方法的发展趋势。     

钢结构的近海大气腐蚀研究

本文结合泉州市某大桥收费站钢结构网架工程实例,探讨了近海大气中钢结构的耐腐蚀性能。分析了近海大气环境中,影响钢结构腐蚀的原因,钢结构腐蚀的类型和机理,并提出了近海大气中钢结构的防腐措施。     

珠海市水工钢闸门的腐蚀与防护

对引起水工钢闸门腐蚀的因素进行了分析,介绍了水工金属结构防腐蚀的方法,并对喷锌防护的施工工艺进行了详细的讨论,以有效地控制钢铁的腐蚀,延长钢闸门的使用寿命,确保水利水电工程的完整和安全。     

提高钢筋混凝土桥梁耐久性的措施研究

钢筋混凝土桥梁的腐蚀与劣化是桥梁运营中的一个不容忽视的问题,对既有桥梁进行病害检测与修复是提高其耐久性的必要措施,文中阐述了桥梁工程中钢筋及混凝土的腐蚀机理,分析了不同的病害原因,并制定了针对性的修补措施,提出对桥梁要进行整体保护。     

Effect of degree of corrosion on the properties of reinforcing steel bars

This paper reports results of a study conducted to assess the effect of degree of corrosion of reinforcing steel bars on their mechanical properties. Reinforcing steel bars, 6 and 12 mm in diameter, that were corroded in reinforced concrete specimens were removed and tested in tension. Results indicated that the level of reinforcement corrosion does not influence the tensile strength of steel bars, calculated on the actual area of cross-section. However, when the nominal diameter is utilized in the calculation, the tensile strength is less than the ASTM A 615 requirement of 600 MPa when the degree of corrosion was 11 and 24% for 6- and 12-mm diameter steel bars, respectively. Furthermore, reinforcing steel bars with more than 12% corrosion indicates a brittle failure.     

钢筋锈蚀产物膨胀在混凝土中产生的应力分析

钢筋锈蚀在混凝土中所产生的应力与钢筋直径损失、钢筋锈蚀产物的体积膨胀率以及混凝土保护层厚度等参数有关 ,本文根据木斯海立什维立的复变函数表示方法 ,从理论上确定了保护层开裂前钢筋周围混凝土中应力与钢筋直径损失等参数的关系 ,并且确定了当钢筋与混凝土接触面处的环向正应力σθθ达到抗拉强度ft时 ,钢筋的临界直径损失理论解 ,对今后进行试验研究和工程应用有一定意义。     

Corrosion protection and assessment of weathering steel highway structures

Three studies, undertaken to investigate various issues related to the corrosion of weathering steel highway structures, are presented in this article. The first study examines the effects of corrosion products and pitting on weathering steel plate thickness measurements obtained using a standard ultrasonic gauge. The second evaluates the potential of several zinc-based coatings, including metallizing and zinc tape, as a way of protecting elements of existing corroded structures. The third study comprises a series of reliability analyses of composite weathering steel overpass structures with uniform corrosion occurring at various locations and rates. Based on this work, it is concluded that the examined coatings offer an effective way of improving the corrosion performance of weathering steel structures. From the reliability analysis study, it is concluded that corrosion can cause significant reductions in the service lives of weathering steel highway structures. The analysis results are seen to be most sensitive to the modelled corrosion conditions. Plate thickness measurements are seen to be vital for the assessment of weathering steel highway structures, due to the high uncertainty associated with the corrosion rate.     

碳化与氯盐复合作用下硫氧镁胶凝材料的护筋性

为探究硫氧镁(MOS)胶凝材料的护筋性,研究了自然养护、碳化、氯盐以及碳化和氯盐复合作用下MOS胶凝材料的电化学阻抗、钝化和脱钝钢筋的极化曲线以及锈蚀面积率.结果 表明:碳化、氯盐单独作用下,MOS胶凝材料中钢筋的阻抗均低于自然养护下的相应阻抗,且随着龄期的延长,钝化钢筋的阻抗均呈现先减小后增大的趋势,脱钝钢筋的阻抗则持续减小;碳化和氯盐复合作用下MOS胶凝材料中钢筋的锈蚀程度明显增加,碳化和氯盐复合作用对MOS胶凝材料内部钢筋锈蚀程度具有叠加效应;各种腐蚀环境中脱钝钢筋的锈蚀程度均高于钝化钢筋.