Short on time, not quality

Highway Construction Article December 28, 2000
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In 1996, the New Mexico State Highway and Transportation Department (NMSH&TD) embarked on its largest and most complex intersta


In 1996, the New Mexico State Highway and Transportation Department (NMSH&TD) embarked on its largest and most complex interstate reconstruction project, I-40.


The I-40 Upgrade included many novel approaches, such as innovative contracting methods, that resulted in early completion of the project. As part of a commitment to accommodate the traveling public, the NMSH&TD required at least three lanes be open in each direction for traffic at all times. Additonally, an extensive public relations campaign kept motorists informed and elevated positive public opinion. The smooth-riding project also went on to win six awards.


The $35 million job encompassed the reconstruction and widening of a 2.2-mile stretch on I-40 from 6th Street to the Rio Grande. Part of a five-year, $350 million plan to reconstruct I-40 through Albuquerque, the project included, in part, 22 lane miles of concrete paving, the widening of six bridges and 350,000 cu yd of excavation—most of which was unanticipated.


A team of Albuquerque professionals joined the highway department in a formal partnering agreement to get the job done as efficiently as possible. A.S. Horner Inc. was the prime contractor, employing 15 subcontractors, while Bohannon-Huston Inc. designed the project and Lafarge Corp. supplied the concrete.


Precipitating reconstruction


As the only major east/west corridor through Albuquerque, I-40 takes commuters to the downtown business district and tourists to the Old Town area. The original 25-year-old highway had been constructed with 8-in.-thick unreinforced concrete.


"Alkali silica reaction problems had taken their toll on the road," said Dirk Holtman, A.S. Horner vice president.


Steadily increasing traffic counts had reached 100,000 vehicles per day, with a large percentage of heavy trucks.


The highway also needed to be widened; the original road was three lanes in each direction, without auxiliary lanes. The project added two lanes in each direction and auxiliary lanes between interchanges. For motorists getting on the highway, the lack of auxiliary lanes made it nerve-racking and dangerous to merge into full-speed traffic.


"We got rid of those weaving movements," said Ted Harris, NMSH&TD project manager. "The additional lanes make the highway a lot safer."


Efficient design


The new road features a 4-in.-thick open-graded, cement-treated base course topped by 12 1/2 in. of concrete. The joint spacing is a variable repeating pattern of 12, 13, 14 and 15 ft.


The contractor found it necessary to redesign the layout of the longitudinal joints.


"The original contract plans showed the longitudinal phase line coinciding with the longitudinal edge of the concrete paving," said Holtman. "However, this would not allow room for the slipform paver. We solved the problem by moving the joint on four lanes and making one lane slightly narrower."


The contractor also convinced the highway department to change the base from asphalt-treated to cement-treated. The contractor had to place the open-graded base course during the winter and was not sure temperatures would reach the 50û mark required to place the asphalt base. NMSH&TD had very little experience with cement-treated bases, but approved its use.


"Once cured it was very stable, raveled very little and provided the drainage required by the NMSH&TD," said Holtman.


Methods speed construction


"Speed was the driving force on the I-40 Upgrade project from its conception," said Holtman.


For the first time, NMSH&TD used A+B bidding and lane rental to reduce motorist inconvenience and construction time.


"Under normal bidding procedures, the contract was estimated to take 800 calendar days," said Holtman. "A.S. Horner committed to complete the project in 472 days."


This was 128 days less than the NM-SH&TD estimated construction time.


In the A+B bidding method, the final bid included construction cost plus the number of days required to complete the project times the daily road user cost. For this project, NMSH&TD figured the user cost at $20,000 per day. The highway department paid the contractor that amount for every day he finished ahead of schedule, up to 50 days. A.S. Horner earned the maximum bonus of $1 million.


Based on the success of the I-40 Upgrade, NMSH&TD has used the A+B bidding method on six projects since then.


"We even tried A+B+C on one project, where ‘C’ was the city’s portion of the cost," said Harris.


Challenges accomplished


The biggest challenge of the project, according to Holtman, was maintaining the schedule without sacrificing quality. The average profile index was 4.7 in. per mile on a .20 blanking band. NMSH&TD offered an incentive for smoothness, and 80% of the pavement met the criteria.


Surprisingly, this was A.S. Horner’s first slipform paving job and Holtman attributed the first-time success to many factors. The main key to the slipform paving was the training of the crew, which attended a comprehensive 2 1/2-day course sponsored by FHWA and the American Concrete Pavement Association (ACPA). It also was attended by NMSH&TD people.


"The joint training of both our crew and the personnel from the NMSH&TD proved to be very beneficial throughout the project," said Holtman.


He also felt that the solid cement-treated base and newly excavated subbase contributed to the smoothness of the road. The consistency of the concrete supply, paving speed and slump also ensured smoothness of the finished pavement.


Another important factor in producing a quality ride was maintaining a consistent head of concrete in front of the paver.


"Too much concrete in front of the paver caused it to float over the surface, and too little concrete caused it to set down," said Holtman. "Since the feeding of the paver was a critical element to achieving a quality project, we added an extra person to our crew. His primary responsibility was to direct the placement of the concrete and to insure a consistent head."


Sub-excavation adds time/cost


The contractor discovered that the sand and clay in the soil under the base course had absorbed water.


"The best way to describe the embankment was ‘spongy’," said Holtman. The original contract included 6 in. of excavation under the base course, amounting to 30,000 cu yd of dirt. Due to the unstable embankment, the contractor ended up removing and replacing up to 4 ft of soil, adding up to 280,000 cu yd of sub-excavation.


The contractor replaced the subbase with dirt borrowed from an interchange a few miles away. The borrowed material was then replaced with the newly excavated I-40 dirt.


"The borrow pit at the intersection was graded and seeded, and today there is very little evidence that more than 200,000 cu yd were borrowed," said Holtman. "This idea saved the NMSH&TD more than $750,000."


Harris cited the unstable subgrade as the biggest challenge of the project.


"That $2.5 million change order came as a big surprise," he said.


The unexpected sub-excavation not only upped the cost, but also added 75 days to the schedule.


According to Holtman, it was a tribute to the partnership between NMSH&TD and A.S. Horner that this large quantity of unanticipated work was smoothly incorporated into the schedule with minimal impact.


"Although more than $7 million of additional work was added to the contract, the project was completed in only 21 more days than the original contract time," said Holtman.


Keeping the public happy


A big priority on this project was to minimize user delay and keep the community informed.


"We know this is going to be a huge inconvenience to the public," said NMSH&TD head Pete Rahn prior to the start of the project, "but we have every intent to keep it from being a nightmare."


Throughout construction, the highway department kept traffic flowing. The contractor built the two new outside lanes first, keeping three narrowed lanes open to traffic through Phase I of the project. During Phase II, the contractor moved traffic to the two new lanes and reconstructed the existing inside lanes. Most of the concrete paving was done at night with lower traffic volumes and cooler temperatures. Although night work was more challenging for the paving crew, it gave the haul trucks quicker and safer access. The production rate at night was higher due to faster delivery and the fact that the entire Lafarge concrete plant could be devoted to the project.


NMSH&TD dedicated more than $500,000 to an extensive media campaign. An advertising agency spent 14 months prior to the project developing the public relations strategies making sure the media received daily reports on the construction and its delays. The campaign included humor as well as project specifics.


Signs at the entrance to the construction zone read, "Through this maze of machines and rubble, driving fast can cause you trouble, take it slow. I-40 Upgrade" and "Construction is a real mess, but these new lanes will ease your stress."


These messages, written by local citizens who won a radio station contest, were changed frequently.


The campaign also included 10 solar-powered message boards throughout Albuquerque, radio and television ads, a webpage, newsletters, water bill inserts, telephone hot lines staffed by real human beings and the creation of Interstate Ernie, a human-size roadrunner who came to both symbolize and personalize the project. Ernie received his name from area school children who entered the "Name the Roadrunner" contest. Interstate Ernie appeared at all the important events in Albuquerque, including the Albuquerque International Balloon Fiesta. Even professional race car driver Bobby Unser got involved, appearing on television ads urging drivers to slow down in the construction zone.


The campaign proved successful, leaving the public with a positive image of both NMSH&TD and the contractor.


The campaign received the EXCEL award in 1997, the highest public relations award given by AASHTO. A public opinion survey revealed that 82% of Albuquerque residents were aware of the project, and that only 36% said they had been inconvenienced by the construction.


Award-winning effort


Since its completion in December 1997, the I-40 Upgrade has been nominated for numerous awards, and has won most of them. In 1997, it received the NMSH&TD National Quality Award in the urban highway category. In 1998, the ACPA recognized the project with its National Excellence in Concrete Pavement Award and also as the year’s top


concrete paving project with its Best of Show Award. Recently, the project received the New Mexico Chapter ACI 1999 Excellence in Concrete Award. The project finished as one


of eight finalists—a gold level winner—in the 1999 National Quality Initiative Award program sponsored by the FHWA.


The key to success


"The biggest factor in the success of the project was the excellent organization on the part of the contractor," said Harris. Holtman attributed the high level of performance to the outstanding cooperation between the contractor and NMSH&TD, and to the effort put forth by each individual involved in the project.


"It’s the folks out there every day doing the work," he said. "They’re the key to our success."


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