Heat, humidity, high quality: Iowa paving contractor hits his mark during sizzling summer

By: Bill Rieken

One of the field tests last summer on a Benton County, Iowa, highway just happened to coincide with a record-breaking heat wave. The RoadMix MTV kept its cool, allowing the L.L. Pelling Co. of North Liberty, Iowa, to establish a continuous paving process so the contractor could lay a superior mat and use fewer trucks.

For the 13,000-ton application, Pelling needed only 14 trucks to make the 40-mile roundtrip loop from plant to jobsite and ensure a continuous flow of material to the paving train. “If we would have delivered directly to the paver, we would have needed approximately 20 trucks,” said Brett Finnegan, vice president of L.L. Pelling Co. Beyond continuous, non-contact paving and more efficient trucking, the MTV’s in-hopper re-blending augers helped to improve mat uniformity and quality. “When working on other projects without the MTV, we would occasionally see little chunks of asphalt slip through the paver and into the mat,” said Jack Robinson, L.L. Pelling’s paving foreman. “The RoadMix breaks up those chunks and gives us a more consistent mat.” Two sets of two in-hopper, counter-rotating remix augers allow the CR662RM RoadMix to re-blend material to deliver a more homogeneous mix to the paver.

The 12-in. constant-diam., variable-pitch augers reblend 100% of the material to combat material and thermal segregation. Remixing benefits both the MTV and paver functions of the machine. Machine utilization is a key consideration for today’s paving contractor, especially when it comes to the hundreds of thousands of dollars spent on material transfer vehicles. For machines that typically average utilization rates of less than 50%, contractors have had to think long and hard before purchasing an MTV.

Terex/Cedarapids now makes this decision much easier with its quick-attach spreading auger and screed designs for the RoadMix, which allows the MTV also to be used as a paver. This double duty will boost utilization rates for the CR662RM by giving contractors two machines in one.

The change from MTV to paver is accomplished in a matter of hours. Contractors simply drop the conveyor legs, disconnect the assembly from the tractor and drive away. After attaching the hydraulic cylinders, tow arms and spreading auger assembly to the tractor, the operator simply backs into the screed. A new outboard drive spreading auger design, currently in field testing, promises to reduce the occurrences of centerline segregation.