Common keyhole methods involve creating a pavement opening usually between 300mm (12") and 600mm (24") in diameter, usually made with a circular core-hole cutter, allowing for remote access to the facilities.
Restoration is accomplished by replacing the cored pavement coupon after repairs are made.
With the help of specialized, long-handled tools, various utility operations can be conducted through a keyhole opening.
These activities include: potholing/depth checks, plastic pipe squeeze-offs, service installation, mains and service abandonment, cathodic protection, inspection and cast-iron joint sealing, amongst others..Reinstatement
Backfill and soil compaction are integral to the effective replacement of the cut core. Using the proper materials during backfill and core replacement will prolong the life of the pavement.
After proper backfilling the keyhole core that was originally cut from the pavement is reinstated back as a permanent restoration of the roadway using special bonding products.
Site restoration requires no temporary patching, overnight road plating, or return trips to make final restorations. The road is restored to traffic-bearing strength in as little as 30 minutes following job completion.