Erosion Control March/April 2017 : Page 44
channel. It was locked in with an anchor trench, backfilled with soil on one side, and secured with a ramset nail on the other. A 6-inch-wide anchor trench “ties the installation in at the top of the origi-nal channel, and that is backfilled with concrete so water can’t get underneath either the Concrete Cloth or the actual channel lining.” Al Gordon, project manager for Bowerman Landfill, says, “The Concrete Cloth acts as a liner. The water just flows right over it. The trick is to make sure you saturate it very well so you get a good cure for the concrete. Once that’s done, it’s a very simple application.” “You lay it down and hold it in place with percussive anchors, then wet it with water and it starts to cure,” says Sjoquist. “It starts to cure within 24 hours, and within 48 hours it’s twice as strong as a sidewalk.” In a separate application, Bower-man Landfill also used Concrete Cloth to rejuvenate several 330-foot-long, 66-inch-diameter metallic culverts that ran underground, which also provided drainage for the landfill. These conduits had experienced severe corrosion and deterioration from the inside out, with erosion from uncontrolled water cut-ting out voids from the fill supporting the pipes. After backfilling the voids, explains Sjoquist, “You go in, cut off the rusted edges of the pipe and put Concrete Cloth on it, add 30 to 50 years of structural longevity, and end up with a shape that’s clean.” He says, “The pipe bedding was backfilled with a controlled low-strength material.” Starting at the bottom of the slope, the Concrete Cloth went in “crossways on the floor of the culverts in 60-inch-wide swaths going up the sides, past the highest high-water mark that’s ever been recorded.” Workers cut sheets of the material from the rolls and hand-carried them into the culverts, a job Sjoquist says would be challenging for him personally, conceding his dis-comfort with enclosed spaces. However, other than a tolerance for the working environment, the job required little specialized skill. Workers simply lay the sheets down with a strategic overlap of 4 to 6 inches, starting at the bottom and working their way up through the conduit. Using seven, bulk rolls CC8 material—a Concrete Cloth with a 44 EROSION CONTROL thickness of 8 millimeters—the total job involved around 10,000 square feet. Sjoquist says the advantage in using Concrete Cloth to line a culvert is that it creates a protective wall that is very thin but very strong, resulting in mini-mal impact on the conveyance’s flow capacity. Concrete Cloth is easy to apply, he notes. “It comes on a roll that looks like a filthy piece of carpet, and in three different thicknesses. Depending on the slope, the customer decides whether to install it in a crosshatch or in perpen-dicular runs.” Gordon says, “We were impressed ral setting. Since the nurse’s visit more than a century and a half ago, Rock City has been visited by millions of nature lovers, vacationers, and sightseers. They come not only to view the beautiful and unusual rock formations, but also to enjoy attractive manicured gardens his firm maintains, the natural beauty of the regional landscape, and the colorful foliage at the change of the seasons. He says that has brought overflow volumes of traffic for at least 20 days of the year during holiday seasons and particularly in the fall when the mountainsides gleam with color. Although Chapin concedes that with this product; once you get the hang of it, it installs easily. We could see ourselves using it on an open-cut trench but we just haven’t had the opportunity to do it yet.” Of the good reviews the landfill has received for its innovative approaches to both infrastructure and service, Sjoquist notes, “It’s the first landfill I’ve ever been to where you feel cleaner when you come out than when you went in.” Fresh Parking Without Paving Paradise Rock City first got its name when a nurse, following the conflict and the casualties of the American Civil War, found herself among the stone outcrop-pings in the landscape of the Lookout Mountain region of Tennessee. “It was like a city of rocks and they, to her, looked like streets and alleyways,” says Bill Chapin, owner of Rock City Inc., a botanical garden and popular tourist attraction ensconced in this scenic natu-the tourism business has its ebbs and flows, coinciding with economic conditions, an uptick in tourism in the Chattanooga area over the past eight years had begun to put pressure on the neighborhood where Rock City is located. With the rising popularity of the attraction, Rock City resorted to parking guests’ vehicles on the streets in the neighborhood—“and our neighbors complained,” he says. The company however, owned a parcel of land in the neighborhood that Chapin believed could be converted to parking during seasons of high traf-fic. He describes the area as a 1.5-acre grassy meadow, which, by coincidence, had been adapted by the neighborhood residents for use as a park and children’s play area. With a need for nearly 150 additional spaces on a seasonal basis, the company-owned lot looked like a perfect solution for Rock City’s parking woes. However, Chapin believed, and conversations with WWW.EROSIONCONTROL.COM ROCK CITY A bridge connects the two segments of the parking area.