It’s the Chia Pet of concrete application, and it’s revolutionizing the industry. Concrete fabric is a flexible, cement-impregnated material that hardens when hydrated to form a thin, durable, waterproof and fire resistant reinforced concrete layer without the need for mixing equipment. The innovative technology can be used on slopes, in water and on other hard-to reach places without molds, heavy equipment or the need for additional manpower.
“It is a very interesting concept that people gravitate to easily once they see it in action,” said Rich Pilston, business manager at Millikin and Co., Spartanburg, S.C. “It began as an entry in an engineering competition, but now has a lot of interesting uses that can benefit cities and municipalities throughout the world.”
Birth of the innovation
Developed by UK engineering students Will Crawford and Peter Brewin in 2005, it began as a formula to procure a rapidly deployable shelter for disaster relief; however, it grew to include a number of long-term and temporary applications at the local, state and federal level including: ditch lining, slope protecting, pipeline protection, bund lining, ground resurfacing, among others.
Concrete Cloth, an offshoot of Concrete Canvas, is not only an innovative material, but a sustainable one that reduces the amount of material used on a project as much as 95 percent. It also boasts a low washout rate and lowers the emissions released into the air during a project.
The product comes in batched or bulk rolls in varying thicknesses, weights and coverage area. The slimmest option is CC5. It is .20 inches thick, has a dry weight of 1.43 pounds per square foot and its 656-foot bulk roll length can cover an area of 2,153 square feet. CC8 is .31 inches thick, weighs 2.46 pounds per square foot and comes in a bulk roll length of 373 feet, which covers 1,345 square feet of space. CC13 is the heaviest at .51 inches in thickness and 3.98 pounds per square foot. It can cover 861 square feet with its bulk roll length of 239 feet.
“It’s the perfect solution if you have a small job that needs to be done quickly,” Pilston said. “It’s quick, easy and doesn’t require a lot of specialized labor.”
Communities that have used concrete fabric have been pleased by how easy it is to install. When the city of Olney, Ill., needed to extend a public boat ramp at East Fork Lake, workers prepared a gravel bed and capped it off with a layer of concrete fabric to provide the hard trafficking surface and prepare the gravel sub-grade. It was a project that took only two calendar days to complete, and the cost was much less than traditional poured concrete.
According to a case study of the Olney project, day one was devoted to site preparation. The existing gravel was removed, and the subsurface was readied for 18 inches of new gravel graded to extend the angle of the existing ramp. On day two, the final adjustments were made to the gravel substructure, and two large panels of CC13 were pulled into place using a backhoe. The underwater contractor guided the operation.
A third panel was placed perpe ndicular to the others, and all three were secured to the existing concrete slab. The entire project was finished by 4:30 p.m. and only cost the city $26,270.
Olney City Manager Larry Taylor said that to extend the ramp another way would have involved creating a cofferdam to remove the water from the area. Using a concrete fabric was a faster and more effective solution.
“We used it not only for the ramp, but also on a concrete channel in a ditch on a creek,” he said. “Using Concrete Cloth on a steep slope helps prevent erosion and eliminates the need to mow and weed eat on these difficult to reach areas. It’s a great option for a number of applications.”