Exploring Polymer Cross-Linked Aerogels for Their Strength and Energy Absorption in Seismic Retrofit of RC Structures

该奖项的研究目标是研究聚合物交联气凝胶--一种带有聚合物涂层纳米颗粒的纳米封装材料--在用于钢筋混凝土结构的抗震加固和保护的减震增强(DES)系统中的有效性，并为在这些结构的基于性能的设计中使用该系统制定设计指南。DES系统综合了通常分开使用的强化和减震两种属性。这项研究将对气凝胶的强度和能量吸收能力进行表征，利用气凝胶创建具有优化的阻尼和强化属性的紧凑型DES保护系统，并开发在不同震级的多次地震下使用DES系统的结构的基于性能的设计方法。为了研究DES系统在桥梁抗震加固中的性能，将对DES系统进行数值模拟。可交付成果包括气凝胶材料性能规范、翻新系统与现有结构之间界面行为的表征、系统的制造和测试以证明其有效性、建模、分析和设计工具与DES系统，以及工程学学生教育。这项研究的结果将为创建紧凑、经济高效的工程系统提供机会，使关键基础设施的基于性能的设计能够最佳地使用减震和加固材料。实例应用包括建筑物和桥梁的抗震改造，在不同的地震和多个性能目标下具有优化的性能。DES系统具有阻燃和抗冲击的优点，可用于其他土木工程和机械工程应用。研究结果将被公布，以便实现一个原型DES系统，该系统增加了设计灵活性，降低了成本，减轻了重量。工科研究生将从课堂教学和参与研究中受益。将邀请K-12学生通过示范项目为他们提供第一手经验。

The research objectives of this award are to study the effectiveness of polymer cross-linked aerogel -- a nano-encapsulated material with polymer coated nanoparticles -- in a damping-enhanced strengthening (DES) system for seismic retrofit and protection of reinforced concrete structures and to develop design guidelines for the use of this system in performance-based design of these structures. The DES system integrates the two attributes of strengthening and damping which are often used separately. The study will characterize the strength and energy absorption abilities of the aerogel, create a compact DES protective system with optimized damping and strengthening attributes using aerogel, and develop methods for performance based design of structures with the DES systems under multiple earthquakes of varying magnitudes. The DES system will be numerically modeled to study its performance in seismic retrofit of bridges. Deliverables include aerogel material performance specifications, characterization of the interfacial behaviors between retrofitting system and existing structure, fabrication and testing of the systems to demonstrate its effectiveness, modeling, analysis and design tools with DES systems, and engineering student education.The results of this research will provide an opportunity to create compact, cost-effective engineering systems that enable the performance-based design of critical infrastructures with an optimal use of both damping and strengthening materials. Example applications include the seismic retrofit of buildings and bridges with optimized performance under different earthquakes and multiple performance objectives. The DES systems offer the advantages of being flame retardant and impact resistant and can be used in other civil and mechanical engineering applications. The research results will be disseminated to allow the implementation of a prototype DES system that has increased design flexibility, reduced cost, and reduced weight. Graduate engineering students will benefit through classroom instruction and involvement in the research. K-12 students will be engaged to provide them firsthand experience through demonstration projects.