WATER/WASTEWATER STRUCTURAL STRENGTHENING
Two 72-inch diameter corrugated metal (CMP) culverts in Greenville, AL, had sections at the invert that had rusted through. The cost to cut open then replace the culvert was prohibitive, but this culvert could not be left alone without further degradation, which could jeopardize the overlying roadway.
Pipe sections had been added over the years as the road was widened and the culvert now consisted of three 20-foot sections, for a total length of 60 feet. The center section was the oldest and in the greatest need of repair, so full excavation and closure of the road was the conventional option. This option would have required closing the road for a minimum of several weeks at a cost of at least $100,000.
The county engineer decided to use Concrete Cloth GCCM as a trial application because the product is easy to install, the project was expected to take less than one day, the installation would not require excavation, and the total project cost was expected to be very competitive.
The contractor arrived onsite at 9:00 am and set up his cutting operation. Six foot lengths of Concrete Cloth material were cut from a bulk roll and then laid transverse to the center line of each culvert, centered on the bottom. The six-foot length allowed about a third of the CMP circumference to be protected.
Each piece of cloth was lapped over the down stream panel by approximately four inches, then the sides were fastened to the CMP using galvanized two-inch, self-tapping screws.
Because water was continually running through the culvert, the contractor chose to lay the product transverse to the center line and shingled in the direction of water flow. Installation was completed by 2:00 pm that day.
After the Concrete Cloth GCCM had cured overnight, the top edge of the installation was sealed with tar to limit high water infiltration under the cloth.
The repair was completed successfully, making Concrete Cloth GCCM an efficient, cost-effective choice for CMP repair and protection.
Application: Twin Culvert Invert Lining
Client: Butler County, AL
Location: Greenville, AL
Concrete Cloth GCCM was selected to repair the damaged culvert and was completed within two days. By avoiding excavation, Concrete Cloth GCCM was a cost-competitive solution for the culvert repair and protection.