In a recent report, the Department of Homeland Security stated that the dangers posed by the aging infrastructure to the nation economic health are considered to be as great as those posed by the recent financial crisis. Although aging itself is not a structural failure mechanism, it decreases infrastructure robustness and resilience against natural or man-made hazards. This research will focus on the ignored/disregarded aspect of the corrosion effect on the bond behavior at the rebar-concrete interface of aging reinforced concrete (RC) structures. The results of this research will inform new design standards for disaster resilience of the built environment, where age-related deterioration is allowed/considered during the service life, and also enhance the available condition assessment tools to holistically evaluate the performance of aging RC infrastructure, which, in turn, can be used to develop a quantitative decision support system for optimizing resource allocation. The interdisciplinary nature of the research (including experimental and numerical studies) provides an ideal learning environment for graduate and undergraduate students, and will equip the students with much-needed statistical and reliability analysis tools for risk management. The PI is committed to recruiting and retaining underrepresented undergraduate/graduate students at her institution through existing campus programs.
There are two research objectives: to better understand the corrosion deterioration on bond behavior, and to implement the newly obtained knowledge into structural and risk analysis. Accordingly, five tasks are planned: (1) conduct comprehensive experimental tests on bond performance under monotonic and cyclic loading considering corrosion; (2) assess bond model parameters based on the test data incorporating uncertainties; (3) probabilistically develop the bond stress-slip constitutive law with corrosion effect through a Bayesian updating approach; (4) incorporate the bond deterioration in the structural analysis, including enhancing and augmenting the current design standards, implementing and numerically validating the developed constitutive relation using OpenSees; and (5) conduct a case study to investigate the corrosion effect on the risk quantification. The research will improve the fundamental understanding of the age related deterioration effect on structural behavior. The bond constitutive model formulation considers prevailing uncertainties and provides a rigorous means for update whenever additional experimental data is made available, making the continuously updated constitutive model more robust. Most importantly, the implementation activities will lay the groundwork for the resilience design development, and make it possible to investigate the structural performance subjected to extreme hazards with appropriate consideration of the aging effect.
