OVERLAY THICKNESS & REBAR DEPTH
On asphalt covered bridge decks, the thickness of asphalt overlays may be inaccurate or unknown and original design plans documenting actual overlay depth are missing or incomplete.This can lead to excessive dead loading on bridge decks. The radar survey shall provide an accurate and up-to-date record of the actual overlay depth. Since the depth of the reinforcing steel is also the approximate depth of delaminated concrete, this measure is necessary (along with the area extent of delaminations) to provide volumetric information relative to concrete removal and replacement quantities.