Graduation Semester and Year
2023
Language
English
Document Type
Dissertation
Degree Name
Doctor of Philosophy in Civil Engineering
Department
Civil Engineering
First Advisor
Suyun Ham
Abstract
This dissertation presents electromagnetic wave studies for infrastructure. The research contributes to a comprehensive understanding of electromagnetic wave propagation in moisture and provides insights into corrosion detection and monitoring in reinforced concrete infrastructure. Three major studies are performed to: 1) understand the multiple wave scattering in inhomogeneous moisture medium, 2) validate the experimental reflection through analytical finite difference time domain simulations with experimental measurements, and 3) evaluate the electromagnetic wave responses in the early stage and post stage corrosion experimentally, and 4) develop rapid corrosion monitoring methodology for field applications by employing cutting-edge electromagnetic wave image processing as refer to as 3-dimensional ground-penetrating radar (3DGPR) system. First, the propagation of electromagnetic (EM) waves in a moisture medium is influenced by various key factors, including the dielectric constant, conductivity, and magnetic/electrical permeability. However, the majority of literature studying EM waves in multiple mediums tends to place a greater emphasis on the analysis by the dielectric constant This study of moisture mediums focuses on the importance of the dielectric constant and conductivity, as they play a significant role in EM wave behavior. In the experimental approach, the EM wave response of inhomogeneous moisture mediums undergoing a transition from a wet to a dry state over the course of a day effectively simulates the shift from saturation to drier conditions. To validate the results, EM wave frequency analyses obtained by these moisture mediums were compared with the results of numerical simulations using the finite difference time domain method, alongside moisture weight measurements. By incorporating a comprehensive approach, a deeper understanding of EM wave propagation in moisture mediums and its practical implications. This research will contribute to advancements in technology and offer valuable insights into the behavior of EM waves in various applications. Second, in this study, numerical models are employed with an advanced computation analysis, specifically utilizing the finite difference time domain method based on Yee cell theory and Taylor series. These models are designed to replicate the experimental setup used in the initial study. To ensure comparable evaluations, the numerical model incorporates a similar antenna source and accounts for the inhomogeneity of the medium. To verify the accuracy of the numerical model, the antenna's response is validated against the experimental data obtained from the 1600MHz antenna in an air medium. The results from these numerical simulations demonstrate a frequency analysis pattern that closely resembles the experimental EM wave frequency pattern, showcasing the model's effectiveness in capturing the specific antenna behavior and moisture variation within the medium Third, the extent of corrosion is predominantly influenced by the amplitude response of the EM wave signals. In pursuit of a deeper understanding and analysis of the corrosion process, conducted experimental accelerated corrosion tests on concrete rebar samples in the laboratory. To verify the different corrosion stages, utilized half-cell potentials and surface resistivity measurements. Additionally, radar signals were periodically collected over the course of the experiment for the concrete samples. The EM wave analysis revealed significant variations in both amplitude and frequency during the early and post-corrosion stages. To further validate the findings, employed simulation models were developed using the FDTD method, facilitating a thorough comparison with the experimental data. Additionally, the recorded current and voltage data from the accelerated concrete samples were utilized to comprehensively study the corrosion rate. Finally, a cutting-edge 3DGPR system was developed and demonstrated for rapid bridge deck inspection. The primary purpose of using the 3DGPR system was to identify potential areas of corroded rebar by employing multiple 1600MHz antennas. The novelty of this system lies in its ability to rapidly collect data with a distance tracking system and a bridge data mapping algorithm. Through two field studies of bridge inspection, I effectively utilized the 3DGPR system to provide comprehensive insights into the scanned bridge area. The bridge data mapping algorithm employed in the system enables us to generate a 2D interpolation map highlighting potential reinforcement corrosion areas across the scanned bridge region. This mapping technique offers valuable visual information and aids in the assessment of the bridge's structural integrity. By integrating these multiple approaches, aim to enhance the robustness of the research findings and gain a more comprehensive understanding of the corrosion process in concrete structures.
Keywords
Electromagnetic wave, GPR, FDTD, 3DGPR, Corrosion, Moisture, Corrosion rate, Accelerated corrosion
Disciplines
Civil and Environmental Engineering | Civil Engineering | Engineering
License
This work is licensed under a Creative Commons Attribution-NonCommercial-Share Alike 4.0 International License.
Recommended Citation
David, Dafnik Saril Kumar, "ANALYTICAL AND EXPERIMENTAL OF ELECTROMAGNETIC WAVE PROPAGATION EFFECT ON MOISTURE AND CORROSION IN AN INHOMOGENEOUS MEDIUM" (2023). Civil Engineering Dissertations. 253.
https://mavmatrix.uta.edu/civilengineering_dissertations/253
Comments
Degree granted by The University of Texas at Arlington