Stark Asphalt, headquartered in Milwaukee, is one of Wisconsin’s largest and most progressive paving firms. It has been in business for more than 50 years, operates four asphalt drum mix facilities and, in 2011, completed the single largest asphalt paving contract in the history of the Wisconsin Department of Transportation—245,000 tons of asphalt were laid down on I-94 in a single summer.
Stark works all over the state, running four paving crews in Milwaukee alone. Since 2010, the firm has been using adjustable manhole risers to raise manholes to grade after municipal repaving projects.
“Milwaukee is our biggest client, and they now require adjustable risers for all projects,” said Todd Beaber, Stark paving supervisor. “We’re glad. The cast iron risers we used to use were heavy and inconvenient to place, and they’d often rattle. These risers never do.”
Stark’s preferred adjustable riser is the American Highway Products (AHP) Pivoted Turnbuckle Riser. They are tough, precisely sized, flexible rings made of galvanized steel. The patented pivoted turnbuckle makes the risers adjustable—using a screwdriver as a lever, the AHP riser is expanded with the turnbuckle. A 60-lb force applied 7 in. from the center of the pivoted turnbuckle exerts a 5,600-lb tangential force, seating the riser tightly even if the original rim is worn or out of round. Installing the riser takes about five minutes and provides a new rim for original manholes that exactly matches the grade of new paving lifts.
Stark crews install the adjustable risers just before paving.
“We usually have a couple of guys working just ahead of paving machines,” Beaber said. “It’s nice that these risers are so much lighter than cast iron risers—our crew can carry all they need in a small truck. Really, all they have to do is clean the old rim with a scraper, set in the new riser and tighten it. They’re done in five to 10 minutes.”
One key to the risers’ efficiency is precise sizing. They can be ordered at any diameter—as thin as ¾ in. and up in ¼-in. increments.
“They can be ordered on short notice, but we try to keep an assortment in stock at all times,” Beaber said. “Sometimes we’re moving fast, and it’s nice to have exactly what we need on hand.”
Stark Asphalt sets up to 100 risers annually in and around Milwaukee, and it has set as many as 35 on a single project. The firm also has used AHP’s Inclined Manhole Riser, which uses the same pivoted turnbuckle for easy adjustability and adds in the capacity to tilt the riser as needed to match sloped road surfaces.
“We purchased the inclined risers for a project in Kenosha with a very high crown,” Beaber said. “It was nice to have the ability to exactly match the sloped surface and made for a higher quality roadway.
“We’ve had no failures that I know of,” Beaber continued. “I think they’re the best riser available, and a good value too. Money is so tight on municipal projects, and these risers make it easy to get manholes to the right elevation without excavation and without any rattling.”