CAREER: Increasing Resiliency and Sustainability of Reinforced Concrete against Aging and Seismic Hazards through Novel Materials

这项教师早期职业发展(Career)计划拨款将调查环境老化和地震对混凝土桥梁的综合影响。钢筋锈蚀是混凝土桥梁老化劣化的主要原因，钢筋锈蚀会导致桥梁承载能力显著降低，危及结构安全。将进行一项深入的计算-实验研究计划，以了解钢筋混凝土中与腐蚀有关的主要退化机制，以及地震对退化桥梁结构的潜在影响。将采用高性能纤维混凝土和超弹性钢合金等新型工程材料来提高桥梁构件的弹性。预计该项目的成果将通过延长桥梁结构的使用寿命和降低维修和维护成本而产生直接的社会效益。预计本项目开发的评估、预测和设计工具将作为未来研究和实施的基础，不仅在桥梁中，而且在其他钢筋混凝土结构中，如港口。研究和教育将通过与大学研究人员以及高中教师和他们的学生建立一个社区来整合。The Investigator计划让来自代表性不足群体的大学生参与到该项目中来。与传统混凝土相比，高性能纤维混凝土具有更高的抗裂性、更高的延性、更低的渗透性和更高的抗损伤能力。新型铜铝锰超弹性合金钢筋可在卸载时恢复大应变。此外，它们易于加工，与传统的超弹性合金棒相比，具有成本优势。通过使用这些新材料，本项目的目标是提高桥梁构件的抗震性能和耐久性。将在混凝土结构的劣化过程、新型超弹性合金的热力行为以及劣化桥梁的地震反应方面产生新的知识。

This Faculty Early Career Development (CAREER) Program grant will investigate the combined effects of environmental aging and earthquakes on concrete bridges. The main cause of aging-induced deterioration in concrete bridges is corrosion of reinforcing bars, which may result in a significant reduction in load capacity and endanger the safety of the structure. An in-depth computational-experimental research program will be conducted to understand the main corrosion-related degradation mechanisms in reinforced concrete and potential impacts of earthquakes on the deteriorated bridge structure. Novel engineering materials of high-performance fiber-reinforced concrete and superelastic steel alloys will be employed to increase resiliency of the bridge members. The outcomes of this project are expected to result in direct benefits to the society by extending the lifetimes of bridge structures and by reducing the repair and maintenance costs. It is expected that the evaluation, prediction, and design tools developed in this project will serve as a basis for future research and implementation, in not only bridges but also in other reinforced concrete structures such as ports. The research and education will be integrated by creating a community with university researchers and with high school teachers and their students. The Investigator plans to engage college students from underrepresented groups in the project. High-performance fiber-reinforced concrete exhibits high crack tightness, increased tensile ductility, low permeability, and higher damage resistance compared with traditional concrete. Novel Cu-Al-Mn superelastic alloy reinforcing bars can recover large strains upon unloading. In addition, they are easily machinable and have a cost advantage over conventional superelastic alloy bars. Through use of these new materials, the objective of this project is to improve the seismic performance and durability of bridge structural elements. New knowledge will be generated on the deterioration processes of concrete structures, the thermo-mechanical behavior of new superelastic alloys, and the seismic response of deteriorated bridges.