Imagine being able to use concrete on slopes, in water and on other hard-to-reach places without molds, heavy equipment or the need for additional manpower. Concrete fabric products make it possible, and they’re changing the way municipalities approach concrete application. Both are the Chia Pet of the concrete industry … just add water and watch them go!
“It’s a very interesting concept that people gravitate to easily once they see it in action,” said Rich Pilston, business manager at Millikin and Company, 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
Concrete Cloth is an offshoot of Concrete Canvas, developed by Will Crawford and Peter Brewin of the U.K. In 2005 the engineering students created a flexible, cement-impregnated fabric that hardens when hydrated to form a thin, durable, waterproof and fire-resistant reinforced concrete layer without the need for mixing equipment. The formula was originally used to create a rapidly deployable shelter for disaster relief, but has grown to include a number of long-term and temporary applications at the local, state and federal level that include ditch lining, slope protecting, pipeline protection, bund lining and ground resurfacing.
The product comes in batched or bulk rolls of varying thicknesses, weights and coverage area. The slimmest option is CC5. It’s .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. As a sustainable material, it reduces the amount of total material used on a project as much as 95 percent, has a low washout rate and lowers the amount of emissions released into the air as customary with traditional concrete machinery.
After seeing the product demonstrated at an APWA conference, Daniel Avila, chief technical officer for water utilities in El Paso, Texas, decided it was a prudent material to have on hand for various projects.
“We used it on a small stormwater channel that was in a hard to reach area,” he said. “It really has its advantages, especially if a slope is steep or if it’s an area that cannot easily be accessed by truck.”
Tim Phillips, street superintendent of Maryville, Tenn., hadn’t heard of concrete canvas or cloth either until he attended a product demonstration class and saw the fabric in action. One of the first areas in which he deployed it was a local tile bottom that had rusted out. Though the culvert was still structurally sound, it needed to be resealed in order to give it new life. Concrete fabric saved money and installed quickly. “We didn’t have to block off the road. It didn’t take a lot of personnel and now we can use the rest of that money on another project until we have to do a total replacement.”
Communities that have aging roads, small staffs and tight budgets are good candidates for the new technology. Phillips said he plans to use it until his community can afford a more permanent solution to its concrete needs.