12 foot (3.66m) Roadway + 84 inch (2134 mm) Variable Barrier = ONE MACHINE
|The project was one of the largest ones under construction for the Michigan Department of Transportation. Prime contractor for the $100 million reconstruction project of US 131 through Grand Rapids, Michigan, was Kiewit Western Company. They subcontracted the mainline paving and barrier work to S & N Contractors, Inc.
S & N Contractors turned to GOMACO for a new generation Commander III to slipform their part of the project.
"We were responsible for everything that had to do with the concrete paving and we were looking for a machine that could handle it all. Number one, we were working in such small areas that we needed a smaller machine rather than a big paver," Fred O'Keefe, owner and president of S & N Contractors, said. "Number two, we needed the new generation's versatility because we had a lot of variable barrier wall and we wanted to be able to slipform both phases with the same machine."
The four-track Commander III was set up to pave the new roadway in 12 foot (3.66 m) passes, 11 inches (279 mm) deep.
S & N Contractors was working in such a tight area that most of the time the concrete had to be pumped. There was not enough room for the ready-mix trucks to get through.
"We had to pump the first few lanes of concrete," O'Keefe said. "After the concrete was cured and the lane was established, we could put concrete trucks on the paved lanes to get concrete to the paver."
The 2800 feet (853 m) of new roadway was slipformed over continuous steel reinforcing with joints averaging every 27 feet (8.23 m). Finishers worked behind the machine applying a hand-tine finish.
None of the project could be slipformed in long sections due to bridges. One section would only be 300 feet (91 m) while the next would be over 700 feet (213 m).
"It was a lot of jumping around and it could have been a real hassle for us," O'Keefe said. "The project's limited access and tight time frame required good coordination on our part. If a one hundred feet (30 m) of roadway was ready at the north end of the project, we'd load up the machine on a low-boy trailer and run down and pave that while they were getting the south end ready. The machine is versatile enough that we could load and unload quickly because we could load it fully assembled with the paving package on and pull it off the trailer ready to pour."
The second part of the project involved slipforming a variable barrier wall that ranged in height from 42 inches (1067 mm) all the way up to 84 inches (2134 mm) with no reinforcing. The bottom of the wall had a width of 24 inches (610 mm) and tapered down to 10 inches (254 mm) on top.
"We were using a 45-D, seven-sack mix design and we tweaked it a little bit by putting super plasticizers and water reducers in the mix to meet our specification in order for us to slip the wall that high," O'Keefe said. "The new generation Commander III handled it real well. We were impressed."
A broom finish was applied to the wall and joints were tooled in by hand every 27 feet (8.23 m) and then saw cut later.
The job was a fast-track project with $50,000 a day incentive or disincentive pay. S & N Contractors worked around the clock to meet and beat the strict deadline.
"The weather was almost always perfect and that helped us out," O'Keefe said. "If it rained during the day, we'd work at night. We had light plants on the project and could turn the night into day. It was a high profile job in the state of Michigan, we wanted to make every effort to bring the project in on time."
The increased travel speed on the new generation Commander III also helped them shave time off the project.
"It's fantastic. A lot of times we'd pour one lane and then pull off and back up all the way to the beginning to slipform the second lane," O'Keefe said. "The faster travel speed saved us a lot of time, I mean a lot, a lot of time. We used to have to stop the trucks and have at least an hour of down time while we moved the machine. Now we don't. We just zip right back down and we're ready to go again in a matter of minutes."
S & N Contractors completed the project on time and earned incentive pay for their work. With their first project successfully completed, the company is looking towards the future and finding a niche for their versatile paver.
"We're at the point where we're trying not to be just the curb and gutter guy, but we're also not a mainline paver," O'Keefe said. "We want to fit in the middle where we do the barrier wall, the ramps and all the 12 foot (3.66 m) lanes. I know the new generation Commander III will help us do it."