Description
Corrosion of reinforcing steel bars (rebars) embedded in concrete is a significant maintenance, rehabilitation and safety issue as it relates to the overall health of concrete structures, particularly those subjected to cyclical chloride attack. Over the years several inspection methods have been used to detect and assess this corrosion with limited success. Wideband microwave imaging, using synthetic aperture radar (SAR) techniques, has shown great potential for producing 3D images of structures containing rebars. Although these investigations have shown great promise, a methodical approach to investigate the overall efficacy of this imaging technique has not yet taken place. Steel corrosion byproduct (i.e., rust) is a relatively high permittivity and high loss dielectric material. Relatively high loss factor results in the absorption of the irradiating microwave energy, leading to rebar image becoming less prominent. Hence, high-resolution images of concrete samples subjected to accelerated corrosion are expected to result in a better understanding and limitations of this imaging approach. This paper outlines the results of an ongoing investigation using wideband microwave 3D SAR imaging technique applied to mortar samples with rebars that were cyclically corroded using an accelerated corrosion process. Simulation results show the presence corrosion on rebars can be clearly detected through attenuations of microwave signal. Measurements as a function of mortar water-to-cement (w/c) ratio and corrosion condition are also conducted. Discussion of similarities and differences between the simulation and experimental results are also provided.
Location
St. Louis, Missouri
Presentation Date
06 Aug 2019, 4:35 pm - 4:55 pm
Meeting Name
INSPIRE-UTC 2019 Annual Meeting
Department(s)
Electrical and Computer Engineering
Second Department
Civil, Architectural and Environmental Engineering
Document Type
Article - Conference proceedings
Document Version
Final Version
File Type
text
Language(s)
English
Source Publication Title
Proceedings of the 9th International Conference on Structural Health Monitoring of Intelligent Infrastructure (2019: Aug. 4-7, St. Louis, MO)
Included in
Microwave High-Resolution 3D SAR Imaging of Corroded Reinforcing Steel Bars in Mortar Subjected to Accelerated Electrochemical Corrosion
St. Louis, Missouri
Corrosion of reinforcing steel bars (rebars) embedded in concrete is a significant maintenance, rehabilitation and safety issue as it relates to the overall health of concrete structures, particularly those subjected to cyclical chloride attack. Over the years several inspection methods have been used to detect and assess this corrosion with limited success. Wideband microwave imaging, using synthetic aperture radar (SAR) techniques, has shown great potential for producing 3D images of structures containing rebars. Although these investigations have shown great promise, a methodical approach to investigate the overall efficacy of this imaging technique has not yet taken place. Steel corrosion byproduct (i.e., rust) is a relatively high permittivity and high loss dielectric material. Relatively high loss factor results in the absorption of the irradiating microwave energy, leading to rebar image becoming less prominent. Hence, high-resolution images of concrete samples subjected to accelerated corrosion are expected to result in a better understanding and limitations of this imaging approach. This paper outlines the results of an ongoing investigation using wideband microwave 3D SAR imaging technique applied to mortar samples with rebars that were cyclically corroded using an accelerated corrosion process. Simulation results show the presence corrosion on rebars can be clearly detected through attenuations of microwave signal. Measurements as a function of mortar water-to-cement (w/c) ratio and corrosion condition are also conducted. Discussion of similarities and differences between the simulation and experimental results are also provided.
