Structural Health Monitoring of Corrosion-induced Damage Within Masonry Structures Using Non-Destructive Techniques

腐蚀造成的退化每年给英国经济造成240亿英镑的损失，相当于GDP的1.6%，因此研究如何最大限度地减少对经济和基础设施的破坏是很重要的。18世纪至20世纪之间建造的砖石建筑通常使用金属构件，如夹子、销子、领带等，因为这些砖石墙的结构完整性高度依赖于这些嵌入的构件。建筑师没有考虑到足够的腐蚀保护，现在必须确保避免这些嵌入金属的腐蚀。这是因为一旦被腐蚀，氧化产物通常会占据比原始金属大7-12倍的体积。这会产生一种力，这种力有可能从内到外顶开并破坏周围的砂浆和砌体结构的石头/砖块，因此这种现象被称为氧化顶压。由于气候变化导致的降雨、温度和风速的增加，未来砌体结构中嵌入金属的腐蚀可能会增加。因此，在不破坏或拆除结构的情况下，检测嵌入在砌体结构中的金属元素的腐蚀位置和程度是很重要的。迄今为止，对这一主题的研究主要集中在无损技术在20世纪和21世纪钢筋混凝土结构中检测腐蚀损伤的应用上。我的论文将利用钢筋混凝土技术的最新进展，并扩展和完善其与砖石结构的使用。结合实验室测试和现场应用，将开发一系列技术，用于一次性和连续监测砖石建筑中腐蚀引起的损害。这种方法将及时提高确定腐蚀位置和程度的能力，从而改善维修的证据基础。该项目的总体目标是评估非破坏性技术在18至20世纪砖石建筑结构健康监测中的应用，以识别和监测金属部件的腐蚀。将研究一系列非破坏性技术，如但不限于声发射测试和微型计算机断层扫描，以检测和确定砖石结构中嵌入金属部件的腐蚀产生的信号，以及随后发生在周围砂浆和石头/砖中的任何损坏，例如裂缝。这些技术已经成功地应用于钢筋混凝土结构，但迄今为止从未应用于砌体结构，因此有可能调查它们是否可以用于新应用的有用技术。该项目属于更广泛的EPSRC工程研究领域，更具体地强调结构工程和建筑环境研究领域。

Degradation due to corrosion costs the UK economy £24 billion annually, equal to 1.6% of the GDP and is thus important to research to minimise disruption both to the economy and our built infrastructure. Masonry buildings built between the 18th and 20th centuries were typically built with metallic components such as cramps, dowels, ties, etc. as the structural integrity of these masonry walls are highly dependent on these embedded elements Where adequate corrosion protection had not been considered by architects, it is now imperative to ensure that corrosion of these embedded metals is avoided. This is because once corroded, the oxide products will typically occupy a volume 7-12 times greater than the original metal. This creates a force which has the potential to jack open and destroy the surrounding mortar and stone/bricks of masonry structures from the inside out, giving this phenomenon the name of oxide jacking. Corrosion of embedded metals is likely to increase within masonry structures in the future, caused by increases in rainfall, temperatures, and wind speeds due to climate change. It is therefore important to detect the location and extent of corrosion of metallic elements embedded within masonry structures, without having to damage or dismantle the structure.To date, research on this topic has been heavily focussed on applications of non-destructive techniques to detect corrosion-induced damage within 20th and 21st century reinforced concrete structures. My thesis will utilise recent advances in techniques used with reinforced concrete and extend and refine their use with masonry constructions. Using a combination of laboratory testing and on-site application, a range techniques will be developed for both one-off and continuous monitoring of corrosion-induced damage in masonry buildings. Such a methodology will, in time, lead to enhanced ability to determine the location and extent of corrosion can be determined, thereby improving the evidence base for maintenance. The overall aim of this project is to evaluate the use of non-destructive techniques for structural health monitoring in identifying and monitoring corrosion of metallic components within 18th to 20th century masonry buildings. A range of non-destructive techniques, such as, but not limited to, acoustic emission testing and micro computed tomography, will be investigated for their suitability to detect and determine signals produced by the corrosion of embedded metallic components in masonry structures, and any subsequent damage, such as cracking, which occurs in the surrounding mortar and stone/brick. These techniques have been successfully utilised for reinforced concrete structures but have hitherto never been applied to masonry structures, and thus there is the potential to investigate whether they could be useful techniques for new applications. This project falls under the wider EPSRC Engineering Research Area, with more specific emphasis on the Structural Engineering, and Built Environment Research Areas.