Nondestructive Detection of Delaminations in Concrete Bridge Decks: A First Experimental Study

To detect delaminations in concrete bridge decks, nondestructive techniques (NDT) permit a frequent and large inspection of the slabs without damaging structures. This research was devoted to detect simulated defects in twelve repaired concrete slabs. These were scanned with high frequency ground penetrating radar (GPR) with the common offset (CO) and common midpoint (CMP) methods. The electromagnetic waves speed was determined from CMPs. A 3D visualization program was also created to display the CO measurements. The visibility of the inserted defects revealed to be dependent on their lateral extension, their thickness and their constitutive material.