Experimental and Theoretical Studies toward the Development of New Corrosion-Resistant Steels and Corrosion Inhibitors for Reinforced Concrete Structures

钢筋锈蚀是混凝土结构中最常见的劣化机制之一。据估计，美国民用基础设施每年的腐蚀成本约为250亿美元，其中很大一部分可归因于混凝土中的钢筋腐蚀。因此，以新型耐腐蚀钢和缓蚀剂的形式开发创新的、廉价的和普遍有效的缓蚀策略是至关重要的。为了生产新的、负担得起的材料来抵抗混凝土中的钢筋腐蚀，反复试验的程序在很大程度上是无效的。由于对混凝土中钢筋腐蚀的基本理解存在差距，以及缺乏智能设计和测试新材料的工具，这些新材料的开发也受到了阻碍。本工作的实验和理论相结合的方法将提供弥合这一差距的工具和知识。这项研究将具有深远的社会、政治和经济影响，使研究人员和材料开发人员能够以经济高效的方式假设、设计、优化和测试新材料，以缓解钢筋混凝土结构中与钢筋腐蚀相关的问题。本研究的最终目标是将分子动力学模拟、第一性原理计算和实验性纳米材料表征技术相结合，为理解混凝土中钢筋的钝化和去钝化过程做出变革性的贡献，并创建所需的知识库和工具，以开发廉价但高效的新型耐蚀钢材和缓蚀剂。混凝土中钢筋的钝化、钝化和腐蚀是发生在金属表面10-20纳米层内的原子/分子尺度现象。因此，需要结合纳米材料表征技术和分子水平计算来开发设计和测试新材料的基本认识和工具。基于这些技术提供的新见解，可以对传统钢进行微小、廉价和有效的成分改变，以提高其耐腐蚀性，或者可以设计定制的缓蚀剂来减缓或防止腐蚀。为了追求这些目标，这项研究遵循了多学科的方法，汇集了腐蚀科学、水泥/混凝土化学、电化学、冶金、应用数学、数值模拟、表面分析和理论化学的专业知识。

Corrosion of steel reinforcement is one of the most prevalent deterioration mechanisms in concrete structures. Annual cost of corrosion of civil infrastructure in the United States is estimated to be around $25 billion, and a large part of this amount is ascribable to steel corrosion in concrete. Therefore it is critical to develop innovative, inexpensive, and ubiquitously effective corrosion mitigation strategies in the form of new corrosion-resistant steels and corrosion inhibitors. Trial-and-error procedures to produce new and affordable materials to resist steel corrosion in concrete have been, to a large degree, ineffective. The development of these new materials has also been hindered by the gaps in the fundamental understanding of steel corrosion in concrete and the lack of tools to intelligently design and test new materials. The combined experimental and theoretical approach of the present work will provide the tools and knowledge to bridge this gap. This research will have far reaching social, political and economic impacts by enabling researchers and material developers with the fundamental tools to hypothesize, design, optimize, and test new materials to mitigate issues associated with steel corrosion in reinforced concrete structures in a cost effective way.The ultimate goal of the present research is to combine molecular dynamics simulations, first-principles calculations and experimental nano-scale material characterization techniques to make transformational contributions to the understanding of passivity and depassivation processes of steels in concrete and to create the required knowledge base and tools to develop inexpensive but highly effective new corrosion-resistant steels and corrosion inhibitors. Passivity, depassivation and corrosion of steel in concrete are atomic/molecular scale phenomena that take place within a 10-20 nanometer layer on the metal surface. Therefore, the fundamental understanding and the tools to design and test new materials need to be developed by combining nano-scale material characterization techniques and molecular level calculations. Based on the new insights provided by these techniques small, inexpensive and effective compositional changes on conventional steels can be made to increase their corrosion resistance or custom-designed corrosion inhibitors can be designed to slow down or prevent corrosion. In pursuit of these goals, the study follows a multi-disciplinary approach that brings together expertise from corrosion science, cement/concrete chemistry, electrochemistry, metallurgy, applied mathematics, numerical modeling, surface analysis and theoretical chemistry.