pipeline rehab

AOC R Tunnel Concrete Repair and Nominal Strengthening

Water intrusion though the concrete walls and roof of a tunnel caused severe concrete deterioration. Spalling concrete became a danger to maintenance workers inside the tunnel and threatened to damage the steam and chilled waters lines that run inside the tunnel.

Repairs had to be performed while wearing pressurized particulate filtration masks under temperatures that could reach 120° F in the summer. The surfaces that were repaired were very congested with pipes and tunnel supports.

The miles of tunnel repairs were divided into phases for control and budgetary purposes. For the sections already inspected, specified and awarded, the permanent solution was to replace the deteriorated concrete by means of hand applied, formed and poured or pneumatically applied concrete (shortcrete). In the areas that presented an imminent threat to the maintenance workers, the pieces of spalling concrete were contained by wrapping and anchoring them in place using the Tyfo® SEH-51A system and the Tyfo® SEH fiber anchors.