AASHTO T 323-03 (2020) covers the determination of the interface shear strength of a drilled concrete core sampled from a bonded concrete overlay pavement or bridge deck. This test shall be performed on 100-mm (4-in.) diameter cores of portland cement concrete. This test is applicable if, when retrieved by coring, the concrete overlay thickness is at least 25 mm (1 in.) and the thickness of the base concrete is at least 50 mm (2 in.).