Polymer Coated Steel Tunnel Liner Plate Successfully Rehabilitates Failing Concrete Box Culvert

Posted on March 23, 2018

Located south of Lake Nipigon, on Highway 11 in East McKirdy, Ontario, a 108 year-old, cast-in-place (CIP) concrete box culvert beneath the highway was failing. A long-term solution was required to rehabilitate the aging structure and maintain vehicular access along this busy stretch of highway.  

As there was just one trail on the west side, access to the job site was restricted. Moreover, the remote location and challenging access required that the new structure be constructed from a corrosion resistant product that would deliver extended service life to the structure, but would also be lightweight, easy-to-transport and quick to install.

Armtec proposed the construction of a 4428 mm diameter x 2862 mm long steel pipe arch structure, comprising polymer coated sections of 3200 pi-mm Tunnel Liner Plate. The addition of the polymer coating extended the structure’s service life up to 100 years. The coating used is a unique, solvent-free, environmentally friendly, two-coat polymer coating system for Structural Plate Corrugated Steel Pipe (SPCSP), Deep Corrugated Structural Plate (DCSP) and Tunnel Liner Plate. The zinc-rich base coat provides corrosion resistance, while the top coat polymer layer provides resistance to impact, corrosion, abrasion and diluted, inorganic acid or alkali.

The Tunnel Liner Plates were delivered to the site on relatively small pallets that could easily be moved close to the mouth of the structure. This significantly reduced the distance materials needed to be carried and also shortened installation time. The plates were assembled into continuous rings, advancing the tunnel in 500 mm sections; in total, one hundred and eight Tunnel Liner Plate rings were used to complete the job.

Rehabilitation of the CIP concrete box culvert was successfully completed in October, 2016. Polymer coated Tunnel Liner Plates provided a durable and cost-effective solution to this challenging rehabilitation.

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Upstream end of the rehabilitated structure

The original cast-in place concrete box culvert

Downstream end of the rehabilitated structure