1. L OUISIANA T ECH U NIVERSITY College of Engineering and Science Electrokinetic Hardening of Concrete Structures Dr. Henry E. Cardenas, Ph.D. Jack T. Painter Professor of Civil Engineering Associate Professor of Mechanical and Nanosystems Engineering Director, Applied Electrokinetics Laboratory

2. L OUISIANA T ECH U NIVERSITY College of Engineering and Science Concrete structure Portion of structure removed Patch material filling void in structure Problematic crack Crack Repair of Concrete

3. L OUISIANA T ECH U NIVERSITY College of Engineering and Science 14“ 4 7 Repaired specimen loaded in 3 rd point bending. Bend test specimen with center crack. Crack cut open and replaced by repair patch. Crack Repair Strength Test

4. L OUISIANA T ECH U NIVERSITY College of Engineering and Science V Negative Electrode Positive Electrode Power Supply Side ViewEnd View Repair Interface Repair Electrode I Electrokinetic Nanoparticle Repair

5. L OUISIANA T ECH U NIVERSITY College of Engineering and Science Specimen Fracture Load, P (lb) Strength (psi) Ave. Strength (psi) Treated Repair 12800408 400 22700394 32650387 Untreated Repair 11000146 160 21200175 3 1150168 Undamaged 13820557 560 23860563 33840560 Treatment Impact on Interface Strength Strength Increase Factor (SIF) = Treated Repair = 2.5 Untreated Repair Strength Reduction Factor (SRF) = Undamaged = 3.5 Untreated Repair

6. L OUISIANA T ECH U NIVERSITY College of Engineering and Science Treatment Enhancement Build up nanoparticles right at patch interface Increase bond strength between patch material and original concrete structure Repair Electrode Patch Interface Top Surface This worked very Poorly! Additional Stress, x3 (next to electrode) Interface SRF ~ 3.5 Top surface has the highest stress Lots of room to Optimize: Porosity reduction at patch may enhance strength by factor of 9

7. L OUISIANA T ECH U NIVERSITY College of Engineering and Science Treatment Optimization Place treatment electrode off of patch interface Place the electrode away from top surface Optimize electrode location Repair Electrode Patch Interface Top Surface

8. L OUISIANA T ECH U NIVERSITY College of Engineering and Science 1.00.850.48 0.0 2.7 2.85 3.0 Patch Interface Satisfactory region x y ○ Center of Repair Patch Top Surface Unsatisfactory electrode placement region Optimum Electrode Placement

9. L OUISIANA T ECH U NIVERSITY College of Engineering and Science Acknowledgements Entergy, Charles Turk Daniela Maindardi, Jinko Kanno, James Philips, Israel Popoola, Kunal Kupwade-Patil, Mark Castay, Joshua Alexander, Paul Femmer.