On highway M-20, east of New Era, Mich., a 70-ft metal plate arch culvert was experiencing moderate to severe section loss in the invert from corrosion and abrasion. The steep decline in condition due to corrosion was attributed to the intermittently flowing creek and the invert’s frequent exposure to oxygen; this was observed in early 2017 by Michigan Department of Transportation (MDOT) personnel. The active creek flow could not be entirely stopped during the placement of the Geosynthetic Cementitious Composite Mat (GCCM) as bypass over the road was deemed impractical.
MDOT had plans to replace the 12 ft x 8 ft culvert in 10 to 15 years and desired a repair option that would extend the life of the culvert invert for at least 10 additional years. MDOT’s Grand Region Bridge Engineer Jonathan Bruinsma was introduced to Concrete Cloth GCCM at the annual Michigan Bridge Conference and learned that the fabric would last the required length of time until replacement as well as provide a protective barrier against further invert deterioration. He contacted Milliken Infrastructure Solutions LLC and was assured that the state of the invert’s deterioration made Concrete Cloth GCCM an excellent candidate for the repair.
Installation training and on-site assistance was provided to the Oceana County Road Commission to educate the contracted crew on how to correctly repair the invert using 1,470 sq ft of CC8 fabric. The workers secured strips of the CC8 fabric transversely, shingling the seams in the direction of the creek’s flow to prevent water ingress under the fabric. The CC8 panels were then mechanically secured to the invert with a Ramset tool and fasteners due to the culvert wall thickness, and the edges were sealed with a bitumen-based sealant to complete the fabric installation. The relative ease of installation enabled MDOT to use local Oceana County crews which saved the MDOT critical maintenance funds.
The complete installation took approximately four hours. The ability of Concrete Cloth GCCM to cure under water was a key advantage as creek flow continued slightly abated during placement, and ultimately hydrated and hardened the product. The Concrete Cloth GCCM invert protection is expected to extend the lifespan of the culvert 10-15 additional years. The low-cost and quick repair provided MDOT value by extending the life of the culvert and considerably delaying the need for a more expensive replacement. The success and viability of this repair will lead MDOT to consider the use of Concrete Cloth GCCM on future rehabilitation/repair projects.