On the A60 north of Bitburg, the surface layer and binder course of a section of the highway were in need of rehabilitation.
The project was carried out with state-of-the-art machines from the Wirtgen Group. They enabled the contractor awarded the job to effortlessly fulfill the tight completion deadline specified by the highway authority and simultaneously assured the required paving precision.
In the heart of the Hocheifel region, not far from the Belgian border, the A60 winds through the countryside like a gray ribbon. Well over half of the 20,000 vehicles using the highway every day are heavy trucks, which seriously impact the asphalt surface.
After removal of the damaged asphalt pavement by milling, the task of paving the binder course was the first on the agenda for the paving crew from Kohl Bau. After four days, the crew would have paved 11,000 tons of fresh asphalt mix. To ensure surface precision, the paving contractor from Irrel used products from the Wirtgen Group.
Improved User Comfort
The new Dash 5 generation of the SUPER 2100-5 X Highway Class paver makes it even easier to fulfill these self-imposed high standards. Numerous assistance systems reduce the workload of the paver and screed operators. With a theoretical laydown rate of up to 1,100 tons of asphalt mix per hour, it offers sufficient output for challenging large-scale projects like this.
Seamless Paving With the SB 300 TV
In order to easily achieve the evenness required by the highways authority, Autobahn GmbH, and produce a long-lasting pavement structure, the contractor decided to deploy a SUPER 2100-5 X paver fitted with an SB 300 TV screed with a width of 12 m. This configuration enabled the paving of the entire roadway including the hard shoulder in a single pass. This also eliminated a potential weak point in the form of a central joint. The two screed extensions are hydraulically adjustable up to a total of 2.5 m and give the paving crew plenty of flexibility. Only in the area of the acceleration and deceleration lanes leading to the Prümer Land rest stop on the section is the roadway wider than the working width of the installed screed. This is where a second, smaller, SUPER 1300 paver came into play.
The uninterrupted supply of asphalt to the site was guaranteed by a Benninghoven Retrofit and Vögele mobile feeders.
Paving such an enormous width poses particular challenges for the site logistics. The asphalt was supplied by the contractor's two asphalt mixing plants. Twenty trucks worked full-time getting the asphalt mix to the construction site. But the bottleneck was the site itself.
“When the traffic comes to a standstill in the narrow bit, we have to stop what we're doing, too," said Kohl Bau representative. "There's no other way to get onto the construction site, even though the mixing plants are located in different directions.”
But on this day, there were no problems at all. Load after load was tipped into the material hopper of the Vögele MT 3000 mobile feeder that was responsible for ensuring a continuous flow of asphalt mix to the paver. This machine combination and an extra material hopper ensure an uninterrupted supply of asphalt mix for paving. The machine train moves forward, closely followed by several rollers that ensure optimal compaction of the new asphalt pavement.
Smart Compact Pro
The star player in the team: a brand new HX 90i VS-OS tandem roller from Hamm. It's one of the first rollers to be equipped with the newly developed Smart Compact Pro system. The system uses a new sensor — the Realtime Density Scan — to determine the density of the compacted asphalt in real-time and uses this value for automated control of the compaction force and modes in both drums. This development is a significant step forward in asphalt compaction, because: as all industry experts agree, the real-time density is the decisive parameter for the assessment of quality during compaction. Until the development of Smart Compact Pro, this value was always the missing piece of the puzzle in asphalt compaction.
Better Control, Cost-Efficiency
Another major advantage of using Smart Compact Pro is particularly appealing to construction managers and contractors: The continuous measurement of the real-time density eliminates the need for extremely time-consuming and costly drilling and core sampling. Smart Compact Pro makes a significant contribution to extending the service life of roads through automated compaction based on real-time density, which reduces both short- and long-term construction and maintenance costs.
