Better Roads Digital Magazine
Issue link: https://read.dmtmag.com/i/85927
The recycled pavement on Highway 59 contained 2 percent virgin asphalt by weight – an amount that was continuously controlled by a computer. "Our crew managed to complete 2.5 to 3 miles each day, working 10-hour days," says Andrew Dauk, Midstate's project manager. "The specifi cation for cold-in-place recycling called for tem- peratures to be 50 degrees and rising. We fi gured our production was pretty impressive, considering that average overnight lows for that time of year are in the low-40s and working daylight hours are at their lowest." A CMI-made PR1050 milling machine, working 14 feet wide, followed an asphalt tanker truck to lead off the recycling train and mill the pavement to a depth of 3 inches. The big mill fed a recycler with a screen deck and hammermill crushing system that reduced all material to 1.25 inches in size. "From there it goes into our pugmill and the PG 52-34 asphalt gets added at a rate of 2 percent," says Dauk. "En route to the pugmill, a continuous weighing sys- tem weighs the recycled material. The weighing system is interlocked with a computer that meters out the asphalt at the correct rate." The recycling unit laid down the cold-recycled asphalt in a windrow, and a Cedarapids pickup machine lifted the material into a Vogele paver. Compaction followed. "We ran a pneu- matic roller and a steel-wheeled roller running static," says Dauk. For paving the two lifts in the over- lay, Anderson Brothers used a Blaw- Knox 3200 paver working 14 feet wide. A 40-foot ski, running on the mat's centerline side, helped achieve smoothness. A Topcon electronics system controlled the screed. Two Caterpillar breakdown rollers each made three passes to help achieve density. The intermediate roller was a Caterpillar PS360C rubber-tired ma- chine, and the fi nish roller was an Ingersoll Rand DD110. "We earned a smoothness bonus for that project," says Mike Niemi, senior project manager for Anderson Brothers. "We have very competent people on our crews and we have good equipment." Write 171 on Reader Service Card or visit www.betterroads.com/info TrailKing_BR0212pg08.indd 1 Better Roads August 2012 17 1/21/12 10:46 PM