The goals of the research are to develop an innovative exterior wall system capable of providing anti-terrorism protection and energy efficiency while maintaining cost effectiveness. The research will mesh the techniques used in the precast concrete sandwich wall industry with recent developments in construction materials and reinforcement strategies to create a non-proprietary protection system that can be readily incorporated into domestic and international building construction applications. The system will be capable of resisting pressure demands generated from intentional and unintentional explosions, near contact detonations, and ballistic demands while still maintaining architectural features and thermal efficiency. To accomplish these objectives analytical parametric studies and experimental validation will be conducted through a collaborative research program at Lehigh and Auburn Universities. The parametric studies will evaluate novel materials and reinforcement strategies using both nonlinear dynamic finite element analysis methods and simplified mechanics based approaches. The experimental studies include static, blast, and ballistic evaluations and will be used to validate the models and demonstrate the capability and limitations of the system developed. The research will advance the science of insulated concrete sandwich wall design allowing economically advantageous protection measures to be integrated into the buildings we live and work in. This will directly provide a societal benefit by creating a system that will enhance our national defense. The research will expand ongoing studies on cement based insulated wall systems conducted by engineering organizations and government laboratories allowing current collaborations to be continued and strengthened. Broad dissemination of the research will be accomplished through partnership and involvement of industry representatives from the tilt-up concrete and prestressed concrete markets and participation of research groups from the U.S. Army and Air Force. The program will provide advanced training to undergraduate and graduate students and industry participants through newly developed courses. Underrepresented groups will be recruited for participation in the project.
The overarching goal of the research was to investigate novel concepts for constructing an exterior wall system capable of providing protection against intentional and accidental impulse loading (blast) and penetration threats while advancing energy efficiency and construction cost effectiveness. Specifically, the research was intended to advance technologies associated with using insulated concrete sandwich wall panels (ICSP) through static and dynamic testing, as well as through high fidelity nonlinear static and dynamic finite element modeling. This project was a collaborative research program by Lehigh University (LU) and Auburn University (AU). The AU component of the collaboration was focused on using state-of-the-art simulation software to understand the complex internal resistance and energy attenuation mechanisms involved in defining and optimizing the strength of insulated concrete sandwich wall panels as they undergo large rotations and are subjected to impulse loading due to blast. The modeling methodology developed by the AU team provides a validated approach and guidance for others that will need to simulate the large displacement performance and blast response of insulated concrete sandwich panels. The analyses conducted by the AU team have contributed to improved understanding of the internal resistive mechanics, which will lead to improved strength and ductility of future ICSP designs. The axial load effects component of the investigation has resulted in recommendations for engineering-level analysis methodology and ductility limits that will result in increased use of ICSPs for total precast construction applications in which there is a blast resistance requirement. The project supported the graduate education of two students. A likely near-term broad impact of the project is liberalization of current restrictions on the use of prestressed panels and ICSPs for construction of government buildings and facilities in which there is a blast design requirement. A longer-term impact will likely be improved design and fabrication of ICSPs specifically for protection applications. Increased use of ICSPs will result in lower construction costs, improved thermal efficiency, and increased safety of government buildings and industrial facilities that must be designed for extreme load conditions such as blast and penetration loading.
