Look up the average life of stuff and one learns that a major league baseball lasts six to seven pitches before being retired to the batting practice bucket. The average life of a U.S. $10 bill is 4.2 years. A common goldfish—IF properly cared for—will last 7 to 14 years before going belly-up.
The Iowa Department of Transportation (I-DOT) expects to see a highway road surface last 20 years. That’s one reason why I-DOT let the contract for the 16.037-mile road-resurfacing project for Iowa Highway 92; a stretch of highway between Winterset and Greenfield, Iowa. The approximate 25 miles between the two cities sees an average 1,365 cars daily. The last construction that highway saw was in 1994.
NORRIS ASPHALT PAVING STEPS IN
Norris Asphalt Paving Co. won the asphalt-paving portion of the project. The company is a Sheldon G. Hayes Award-winning paving contractor. The industry considers The Sheldon G. Hayes Award among the most prestigious paving awards, granting it after a 2-year detailed evaluation of the workmanship of the subject roadway project.
Norris Asphalt Paving assigned an 11-person crew of its approximately 75 employees to the Iowa Highway 92 project. The 6-week project began at the end of May 2014. The company was responsible for the paving portion of the highway rehab. The stretch of Iowa Highway 92 is 28 feet wide—two 14-foot lanes. The highway was also widened 2 feet on each side.
Norris subcontracted the milling and roadbed prep work to other contractors. A 4.6-mile stretch on the east end of the project posed a challenge because it had a concrete underlayment. For its contractor to mill the on-average 4.5-inch depth, Norris Asphalt had to close the stretch to traffic for 17 days.
“The rest of the highway project was milled cold-in-place with traffic flow maintained throughout construction,” states Bob Mobley, paving superintendent, with Norris Asphalt Paving Co. “The milled asphalt was recycled—we used 20 percent RAP in our HMA mix.”
For the highway project, Norris Asphalt laid 12,230 tons of HMA for the base lift and placed 24,840 tons of asphalt for the intermediate and surface layers. They used an additional 7,500 tons of HMA for the widened roadway shoulders.
GOOD GEAR IS GOLDEN
“Our paving on this project went quite well,” Mobley says. “We were using a new machine—a Roadtec RP-195e, which is a powerful, rubber-track paver made for highway work.”
Norris Asphalt literally received delivery of the new paver in time to use on the Iowa Highway 92 project.
“Roadtec guys showed up to train us on our RP-195e and after a few minutes we basically said, ‘Not to be rude, but get out of our way … we have work to be done,’” shares Mobley. “The machine is that easy to learn and operate.”
Mobley likes the way the paver steers with its joystick steering and prefers the heavy 40-foot drag screed to no-contact screeds he’s seen on other machines. He mentioned that the dual operator stations can move out beyond the sides of the machine to give the operator a clear view down the sides of the paver. And he likes that the machine is a tread paver.
LIVING UP TO EXPECTATIONS
The better than 16-mile stretch of Iowa Highway 92 is but one chunk of the 275-mile state highway that runs from east to west across the state. The work that Norris Asphalt Paving Co. performed on the project was subject to the I-DOT’s Quality Management – Asphalt (QM-A) program, which holds the contractor responsible for mix design, sampling, testing, and making mix adjustments if necessary. In other words, contractors assumed start-to-finish responsibility for the product they produce and place.
Norris Asphalt’s finished road passed all of the I-DOT random density core tests, which check for voids. The finished asphalt paved surface achieved impressive profilograph-measured 12.61 to 12.9 International Roughness Index (IRI) scores.
When asked how they were able to achieve, what many would consider, exceptional IRI scores on the finished paved surface, Mobley notes, “Superb paving machine and darn good crew!”
For the I-DOT officials signing off on the work, there is a confidence that the highway section is good to go for at least a 20-year life. ■
About The Author:
Jeff Winke is a business and construction writer based in Milwaukee, Wisconsin. Contact Jeff through www.jeffwinke.com.
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Modern Contractor Solutions, February 2015
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