Des Moines Asphalt & Paving Co. was only following the No. 1 objective of highway construction: Keep the masses moving.
The goal was accomplished in a big and unique way during the construction of two new lanes of highway on Iowa 141 in Dallas County in 1997, as over 346,000 tons of material was produced and placed during the project, which finished a year ahead of schedule and earned the company the Sheldon G. Hayes Award for 1999.
The Hayes award is given each year by the National Asphalt Pavement Association (NAPA) to the HMA pavement judged the highest quality in the nation. The pavement goes through three rounds of judging. The National Center for Asphalt Technology was the first to conduct checks, then an independent pavement consulting firm ran tests for smoothness before a final inspection was conducted by an independent pavement engineer.
The makings of something great
Dallas County is one of the fastest growing counties in the state of Iowa, and with growth comes an increase in traffic. Volume has gone up more than 63% this decade. The recent surge explains the expansion to Iowa 141, which handles 8,100 cars and trucks daily, between Des Moines and Perry. The plan called for the 12-mile strip to be converted into a four-lane divided highway, and right from the beginning Robert Jimerson, the project manager for the Iowa DOT (IDOT) on the job, was anxious to see the construction unfold after talking with Jim Gauger, vice president of sales for Des Moines Asphalt & Paving. Gauger also served as project manager for the contractor.
“Jim came to me and told me, ‘We’re here to do a good job. In fact, we’re here to win an award for the project,’” recalled Jimerson. “I figured the award he was talking about was at the local level, I had no idea it would lead to this [the Hayes Award].”
Through competitive bidding with four other contractors, Des Moines Asphalt & Paving won the job behind a cost estimate of $8 million and a completion date set for 1998. The expansion, which took about eight months and $8.1 million to finish, also included the reconstruction of nearly two miles of the existing highway at two separate locations, the relocation of a curve and the building of an interchange. There were no incentives for finishing early, but the company did receive $110,000 in incentives for smoothness. Building on its success, Des Moines Asphalt & Paving is going to resurface the two older lanes this year.
“The weather was good and we just ran pretty hard,” said Robert Goodhue, vice president of operations at Des Moines Asphalt & Paving. “Everything just worked out well.”
Loads and loads of work
The year 1997 wasn’t a particularly good one for dirt contractors in Iowa, not after a wet season. The extra precipitation temporarily delayed the project, which started in late April with trimming of the grade and the creation of a special backfill for the reconstruction of 11/2 miles of road near the new interchange located in the town of Granger. Existing portland cement concrete (PCC) pavement was removed and crushed to meet gradation for the granular sub-base, which was 6 in. thick.
Once the project shifted into full gear the transportation of materials was immense. The project called for 127,000 tons of special backfill, 49,000 tons of granular shoulder rock, 125,000 tons of hot-mix asphalt (HMA) base, 23,000 tons of HMA binder course and 22,000 tons of HMA surface course. Des Moines Asphalt and Paving met the challenge by using a fleet of over 20 trucks to haul and place more than 5,000 tons daily.
“We were just busy and we wanted to get it behind us,” said Goodhue when asked about the accelerated effort. “When you have something like that you just want to get in and get it done. When the crew arrived in the morning the mix was there. There wasn’t any down time, everybody was busy. We just sailed right through the thing.”
The machinery also held up under the higher demands. The company’s Cedarapids M410 batch plant, located 26 miles from the job site, produces an average of 300-350 tons of asphalt an hour, but to match the speed specifications it was churning out 400-420 tons an hour.
“I don’t think another company could have done it,” added Don Stevens, resident construction engineer for IDOT. “The amount of production they pulled off is the main reason it opened up in the fall.”
Paving started in June with the use of Cedarapids 551 and Roadtec asphalt pavers. The two worked in tandem to avoid a center-line joint, which can lead to water seaping into the pavement.
The 12-in. asphalt mix consisted of a 9-in. type B base, a 1 1/2-in. type A binder course and a 1 1/2 type A surface course. The base consisted of 60% crushed particles, the binder course 75% limestone mix and the surface course contained 75% crushed particles with a type 3 skid.
Vibratory, double-drum rollers were used to help with compaction. Three were Ingersoll-Rand models—two DD110s and one DD130—and the fourth was a Cat 634. The company was shooting for a 95% density and averaged 97% through the entire project. The target for voids in mineral aggregate (VMA) was 4%, and an average of 3.5% to 3.7% was achieved.
Smoothness was another key to the project’s success, as the pavement met the state requirements for 100% smoothness. Using a 25-ft. California profilometer, less than 2 in. of roughness per mile was recorded, with a 0.0 rating registering in several spots, according to Goodhue.
Upon completion of the new eastbound lanes, traffic was switched for the reconstruction on the existing westbound lanes. Paving ceased for approximately seven weeks for the construction of the new interchange and the relocation of the curve at the start of September. Final touches on the project were applied in November.
Opening the new four-lane highway before the winter put some worries to rest on a “dangerous stretch of highway,” according to Jimerson. With two additional lanes now in place, an 82-ft median separated the westbound-eastbound traffic.
“The weather held on, the temperature kept us in the paving mode,” Jimerson said. “You’re dealing with extreme traffic control in rush hour, and it had a history of accidents and fatalities. It was important to get that traffic separated.”
Jimerson and others passed credit on to an experienced paving crew which as been together for more than 10 years.
“There was no way I thought they’d get it done when they did,” stressed Jimerson. “This is a crew that can get the job done and put it in the running for an award.”
“They worked an 11- to 12-hour shift and there was just a constant flow of mix,” said Goodhue.
Working well together
The job was an example of the polished version of Iowa’s quality management asphalt program developed five years ago. In the past, the department of transportation handled all tests done on the pavement, and it was a bit time consuming. The DOT would take three hot-box samples, which are samples of the asphalt taken immediately after it is applied to the road, and send them to a district lab for testing, which usually took a day. The quality management asphalt program, however, places the testing in the hands of the contractors. Des Moines Asphalt & Pavement Co. pulled four hot-box samples and monitored cold feeds (material going into the batch plant) daily, ran them to its own lab and had results within hours. By conserving precious time, contractors can spot problems through the testing and make changes immediately.
“Excellent project management, cooperation between DOT and contractor personnel, and a professional work force made this the outstanding project that it was,” said Jimerson.
“Iowa DOT and the asphalt industry have worked together to establish an effective quality management program for asphalt in Iowa. [The Hayes] award indicates the success of these efforts and is a tribute to Des Moines Asphalt and the Iowa DOT project team.”
Following a legend
Before president Bob Horner took over 15 years ago, Des Moines Asphalt & Paving Co. was owned by Ronald Kenyon. Kenyon is a former NAPA chairman who saw the need for an asphalt research facility, and in turn led the push for funding and support of the National Center for Asphalt Technology (NCAT) located at Auburn University, Auburn, Ala. NAPA’s Ronald D. Kenyon Research and Education Award is awarded every year to the individual demonstrating effort and contributions towards asphalt research.
Goodhue has been with Des Moines Asphalt & Paving Co. since April 1965, and the biggest change in the industry he has witnessed is the development of the drum mix plant, which combines both drying and mixing functions in a single drum, significantly reducing the possibility of error. According to Goodhue, Kenyon played a major role in bringing the first drum mix plant to the state of Iowa.