Choosing the right approach to determine an effective culvert repair solution is not always a simple task. There are many factors to consider when deciding on the most relevant repair option for a culvert, which include:
- Type of culvert deterioration
- Root cause of the problem
- Correcting failed conditions on the outside of the culvert at the inlet and outlet
- Solving erosion control and soil stabilization issues
Depending on the state of the failing culvert, it may not need to be structurally rehabilitated but could be lined with a rehabilitative material instead. Choosing a geosynthetic cementitious composite material, or GCCM, to line the existing culvert can extend its life by providing a durable concrete layer to function as a new wear surface in the culvert. The installation of a GCCM requires a limited footprint and can be installed in the rain or other wet conditions with less necessity for road closures or project rescheduling. GCCMS also provide the option to allow agencies to self-perform installations, which would save on project duration and costs.
Concrete Cloth GCCM is a flexible, three-dimensional material impregnated with cement that offers easily handing and installation when using a small crew. The cementitious material hardens when hydrated to form a thin, durable, waterproof and fire-resistant layer that provides a cost-effective alternative to traditional culvert repair methods.
Though GCCMs are typically used as a rehabilitative solution, the West Virginia Division of Highways (WVDOH) elected to use Concrete Cloth GCCM as a preventative measure to a new culvert installed on Route 35. Its ability to be installed underwater and hydrated using an existing water source made it an ideal candidate for the project. A case study of the installation highlights an overview of the project, a solution and the results of choosing a GCCM as the rehabilitative material for this project.
A recent upgrade to West Virginia Route 35 required the construction of several structural plate pipe culverts under deep fills. High water velocities carrying large amounts of sand, gravel and cobbles are fairly common conditions for culverts in West Virginia. Due to the abrasive bedloads that these galvanized steel culverts were likely to experience, the WVDOH required these structures to be installed with field paved concrete inverts as a way to extend their service life. This concrete invert would require a welded wire mesh that was attached to the structure prior to pouring or spraying the concrete.
One of these structures, an 880-ft long, 84-in. diameter structural plate pipe under almost 180 ft of fill, had significant groundwater infiltration. The volume of water entering the culvert through the bolt holes and plate laps prevented the installation of the concrete invert. Concrete Cloth GCCM was presented as a possible solution to the primary contractor, Bizzack Construction, LLC, a company out of Lexington, Kentucky.
Concrete Cloth GCCM’s ability to be installed underwater made it an ideal candidate for this design-build project. Traditionally, Concrete Cloth GCCM is used for rehabilitative purposes. Paul Filipiak, P.E., is the product engineer at Foster Supply and the local distributor in West Virginia, and he suggested the material as an alternate way to protect the culvert invert due to the abrasion resistant properties of Concrete Cloth GCCM.
The prime contractor and its subcontractor, Jim Construction, a company out of Charleston, West Virginia, had never used Concrete Cloth GCCM before this installation. Milliken Infrastructure Solutions field support associates were on-site to help Jim Construction’s team learn how to use the material.
Sandbags were used to mitigate some of the constant flow, but the contractor did not have to worry about having too much water in the culvert while working because of Concrete Cloth GCCM’s ability to be installed in wet conditions. The material was attached to the galvanized steel structural plate using steel nails shot through the Concrete Cloth material and into the plate using a powder actuated tool. The flowing water was actually repurposed and used to help hydrate the Concrete Cloth GCCM because the material cannot be over-hydrated. The edges were sealed with grout to prevent debris from getting in between the Concrete Cloth GCCM and the corrugated steel culvert.
Being very aware of the durability issues plaguing steel culverts in West Virginia, Paul was impressed by the durability of Concrete Cloth GCCM, as well as its ease of installation. And given the number of steel culverts in West Virginia, the positive results have encouraged him to reach out to the highway districts that are responsible for their maintenance to educate them on the benefits of using Concrete Cloth GCCM.
“In some of the more extreme conditions in West Virginia, steel culverts might only last 10 or 15 years before needing rehabilitation or replacement,” said Filipiak. “When that culvert is under a major roadway or 100 feet of fill, you can’t just dig it up and replace it.”
The Concrete Cloth GCCM application has been reevaluated two years after the initial installation and is holding up well despite the abrasive bedloads that continue to flow through the culvert. This extreme preventative application should lay the groundwork for future culvert rehabilitations and preventative measures in West Virginia.
In addition to providing preventative, rehabilitative or repair applications for culverts, Concrete Cloth GCCM can be used for berm and secondary containments, ditch lining, erosion control and slope protection.