WATER/WASTEWATER STRUCTURAL STRENGTHENING
A Corrugated Metal Pipe (CMP) roughly 72 inches wide by 42 inches tall had rusted through the invert in some sections. The cost to excavate the soil overburden then remove and replace the culvert was very high. In addition, there were numerous utilities in the area that would make excavation for total replacement quite difficult. The replacement option would have required closing the road for a minimum of several weeks at an estimated cost of at least $60,000. The Concrete Cloth GCCM solution, including installation costs, would be less than a tenth that cost. The city explained, “Concrete Cloth adds great value to us because our own forces can install the material in a quick and cost effective manner, which we feel is a long-term solution.”
Concrete Cloth GCCM was chosen to line the invert of this culvert, providing protection and extending the useful life of this culvert for years to come. By using the Concrete Cloth GCCM solution, the roadway could remain open and the installation could be performed quickly at a fraction of the cost for excavation, removal and replacement or relining.
The plan for the project required Concrete Cloth GCCM to be laid parallel to the direction of flow and overlapped near the center line of the pipe. At both the inlet and outlet, Concrete Cloth GCCM was used in a trench to prevent water from flowing under the pipe. This would protect about a third of the pipes interior. Each piece would then be overlapped approximately four inches, and the sides fastened to the CMP using galvanized self tapping screws.
On the first day of the installation, the city closed down traffic on this residential street. Concrete Cloth GCCM was unrolled and laid into hand-dug trenches at both the inlet and the outlet. Because water was continually running through the culvert, the city used this water to hydrate the Concrete Cloth GCCM after securing the product to the CMP with screws. Installation was completed by 11 am that same day.
On the second day, the free edge of the cured Concrete Cloth GCCM was sealed with mastic to limit future high water infiltration between Concrete Cloth materials and the pipe.
The City of Maryville chose Concrete Cloth GCCM for this trial installation due to its versatility and competitive installation cost. The complete installation took less than half a day, and utilized the city’s own forces, saving the city time and money. The installation has postponed the culvert replacement for many years to come. In the city’s own words, “We look forward to using Concrete Cloth GCCM in the future.“
Application: Headwall Scour Protection
Client: City of Maryville, TN
Location: Maryville, TN