UNF Digital Commons UNF Graduate Theses and Dissertations Student Scholarship 2018 Coupling Radio Frequency Energy Via the Embedded Rebar Cage in a Reinforced Concrete Structure for the Purpose of Concrete Degradation Sensing Ryan Campiz University of North Florida Suggested Citation Campiz, Ryan, "Coupling Radio Frequency Energy Via the Embedded Rebar Cage in a Reinforced Concrete Structure for the Purpose of Concrete Degradation Sensing" (2018). UNF Graduate Theses and Dissertations. 836. https://digitalcommons.unf.edu/etd/836 This Master's Thesis is brought to you for free and open access by the Student Scholarship at UNF Digital Commons. It has been accepted for inclusion in UNF Graduate Theses and Dissertations by an authorized administrator of UNF Digital Commons. For more information, please contact Digital Projects. © 2018 All Rights Reserved [THIS PAGE IS INTENTIONALLY LEFT BLANK.] COUPLING RADIO FREQUENCY ENERGY VIA THE EMBEDDED REBAR CAGE IN A REINFORCED CONCRETE STRUCTURE FOR THE PURPOSE OF CONCRETE DEGRADATION SENSING by Ryan Campiz A thesis submitted to the School of Engineering in partial fulfillment of the requirements for the degree of Master of Science in Electrical Engineering UNIVERSITY OF NORTH FLORIDA COLLEGE OF COMPUTING, ENGINEERING, AND CONSTRUCTION July, 2018 Unpublished work c Ryan Campiz 1 Certificate of Approval The Thesis of Ryan Campiz is approved by: Date Dr. Brian Kopp Dr. Juan Aceros Dr. Adel El Safty Accepted for the School of Engineering by: Date Dr. Osama Jadaan Director of Engineering Accepted for the College of Computing, Engineering, Date and Construction by: Dr. William Klostermeyer Interim Dean Accepted for the University by: Date Dr. John Kantner Dean the Graduate School 2 Acknowledgements This study would not have been possible without the Florida Department of Transportation (FDOT) — namely Randy Pierce and Ivan Laza. The Florida Department of Transportation supported this study with funding and guidance. This work supported in part by the Defense Advanced Research Projects Agency under contract HR0011-15-C-0098. This study was conducted under Dr. Brian Kopp, who was a wealth of knowledge and information in the RF and Communication fields and helped orient efforts in the most effective way possible — and whose patience is nothing short of a saint. Moreover, Dr. O. Patrick Kreidl, Dr. Juan Aceros, Dr. Adel El Safty, and Dr. Nick Hudyma were all tremendously supportive and charitable with their knowledge and wisdom — Dr. Kreidl and Dr. Aceros for their expertise in electrical engineering topics, and Dr. El Safty and Dr. Hudyma for their expertise in civil engineering topics. Moreover, UNF alumni Marshall Banks, Nick Telmosse, and Juan March were extraordinarily helpful with their mechanical knowledge and CNC skills. Moreover, Jean Loos was overwhelmingly kind with her time and patience in her role as the head of the UNF Fabrication Lab, helping with foolish fabrication mistakes and advising how to correct them. Moreover, Clifford Poppell was also overwhelmingly kind with his time and patience as a Teaching Lab Specialist and overall Jack of all trades. Lastly, this project would not have been possible without Dr. Murat Tiryakioglu and all of his outstanding work as the previous director of the University of North Florida College of Computing, Engineering, and Construction. 3 Table of Contents Certificate of Approval .............................................................................................................. 2 Acknowledgements ................................................................................................................... 3 Table of Contents ...................................................................................................................... 4 List of Figures............................................................................................................................ 6 List of Tables ........................................................................................................................... 16 1 Abstract ............................................................................................................................. 17 2 Introduction ....................................................................................................................... 18 2.1 Motivation of Research ............................................................................................ 18 2.2 Thesis Objective ....................................................................................................... 19 3 Background and Theory .................................................................................................... 20 3.1 Reinforced Concrete ................................................................................................. 21 3.2 Single Line Conduction ............................................................................................ 24 3.3 Energy Harvesting .................................................................................................... 28 3.4 Communications ...................................................................................................... 33 4 Design ............................................................................................................................... 36 4.1 First Design Approach: TM Couplers at 2.4 GHz ................................................... 37 4.2 Second Design Approach: Grounding Clamps at 8 kHz .......................................... 59 5 Experimentation ................................................................................................................ 67 5.1 First Design Attempt: TM Coupler at 2.4 GHz ........................................................ 68 5.2 Second Design Attempt: Grounding Clamps at 8 kHz .......................................... 166 6 Conclusion ....................................................................................................................... 197 6.1 Achievements ......................................................................................................... 197 6.2 Future Work ........................................................................................................... 198 7 Work Cited ...................................................................................................................... 202 4 8 Appendix A – Refining the λ/4 Stub Distance and Determining the Permittivity of PVC at 2.4 GHz ................................................................................................................................. 205 8.1 First Modification to the Stub Distance ................................................................. 207 8.2 Second Modification to the Stub Distance ............................................................. 208 9 Appendix D – Expanded Results for Experiment 11 ...................................................... 211 9.1 Measurement 1 ....................................................................................................... 212 9.2 Measurement 2 ....................................................................................................... 219 10 Appendix B – Embedding the First Design Approach in Concrete ........................... 232 10.1 Construction of the Testing Apparatus .................................................................. 232 10.2 Preparation and Pouring the Concrete .................................................................... 234 11 Appendix C – Pouring Concrete for the Second Design ........................................... 235 12 Appendix E – Improving the Rectifier Circuit ........................................................... 237 12.1 Rectifier with Series Capacitor with a 2.2kΩ Load ............................................... 237 12.2 Series Capacitor and Shunt Capacitor with 2.2kΩ Load ........................................ 240 13 Appendix F – Simulating the Rectifier Circuit .......................................................... 244 14 Appendix G – Evaluating the performance of a Scaled Up Square Rebar Cage ....... 250 14.1 Process and Results ................................................................................................ 251 14.2 Discussion .............................................................................................................. 251 15 Vita ............................................................................................................................. 252 5 List of Figures Figure 1. Visualization of TEM mode (left) and TM mode (right) — E-Field is orange, H-field is blue. ..................................................................................................................................... 25 Figure 2. Generalized Ragone plot showing capacitors, supercapacitors, batteries, and fuel cells. ......................................................................................................................................... 31 Figure 3. Simplified overview of direct sequence spread spectrum, assuming no channel noise. ................................................................................................................................................. 34 Figure 4. Overview of the entire remote sensor. .................................................................... 37 Figure 5. Pictorial representation of some critical dimensions for the TM Coupler. .............. 39 Figure 6. An HFSS