Concrete and asphalt coring cuts a circular hole through the full depth of the pavement — asphalt, concrete, or asphalt over concrete — so the utility beneath can be reached by vacuum excavation. Keyhole coring gives vacuum excavation crews quick, safe access to underground utilities, with minimal disruption to hard surfaces.
OE's road saws and coring machine make the cut, and the core is set aside. After the work, the hole is backfilled and the existing core is reinstated with Utilibond, a bonding compound for permanently reinstating cores in asphalt and concrete roads, sidewalks and other paved surfaces. Where a surface needs more than the core, OE restores it with asphalt or concrete.
Ontario municipal note: municipalities set the rules for coring in their roads. In Toronto, for example, specification TS 4.70 requires cuts to be made with an approved keyhole-coring saw, through the full depth of the pavement, and limits keyhole cuts to 460 mm in diameter. Keyhole cores are not permitted where asphalt is less than 100 mm thick, and should sit at least one metre from other cores, joints and cracks wider than 3 mm. A fractured or defective core is not reused; the opening is filled with new hot or warm mix asphalt instead.