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

Start Date

8-6-2019 4:35 PM

End Date

8-6-2019 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)

Share

COinS
 
Aug 6th, 4:35 PM Aug 6th, 4:55 PM

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.