Which method may be used to confirm delamination via physical sampling?

• A. Core sampling may be used for confirmation.
• B. Visual inspection only
• C. Magnetic testing
• D. Ultrasonic thickness only

Answer: (A)

The key idea is that confirming delamination requires physical evidence from inside the concrete. Core sampling does just that: a cylindrical concrete core is removed through the suspected delamination zone, and its examination shows whether there is a separation or debonded layer between overlays and the substrate. This direct observation provides definitive proof of delamination, something non-destructive methods can only suggest. Visual inspection can’t reveal internal separation, and methods like magnetic testing or ultrasonic thickness don’t expose the actual bonded/unbonded condition across a plane. So, taking a core for inspection is the method that yields concrete confirmation.