Many existing reinforced concrete building structures designed in accordance with pre-1971 codes have non-seismic detailing, which can lead to premature failure under natural and man-made disasters (e.g. earthquakes and blast events). The premature failure can potentially be prevented through the installation of a fiber-reinforced polymer (FRP) column jacketing system. This retrofit system can be used to ensure that existing structures have adequate seismic and blast performance levels as specified in current design codes. However, code-defined performance criteria are composed of different structural demand limits depending on the loading type. These different demand limits may lead to retrofit designs that are insufficient for multi-hazard loading or overly conservative and therefore not cost-effective. The objective of this dissertation is to propose a multi-hazard performance criteria with energy-based damage limits for non-ductile reinforced concrete frames retrofitted with fiber-reinforced polymer jacketing systems. This study performed a series of full-scale seismic dynamic experiments on a non-ductile reinforced concrete test frame retrofitted with a fiber-reinforced polymer jacketing system to measure the seismic response and quantify the effectiveness of the retrofit system. The measured dynamic responses are utilized to propose and verify a seismic modeling methodology that represents a realistic assessment of bond-slip effects between reinforcing bars and the surrounding concrete. Additionally, a blast modeling methodology, which includes bond-slip effects and an advanced blast load modeling technique, was verified with the experimental responses from previous research. The finite element models are incorporated into the development of fast running models using an artificial neural network. Finally, a multi-hazard performance criteria integrating the energy-based damage demands is derived using the fast running models to determine seismic and blast damage limits corresponding to code-defined performance levels. This multi-hazard criteria is used to develop an effective retrofit design for an FRP column jacketing system under specific seismic and blast loads.
Dr. David W. Scott and Dr. Lauren K. Stewart
Dr. Seung-Kyum Choi (ME), Dr. Reginald DesRoches, Dr. Chuang-Sheng Yang