On the A9 job site, this paving set laid down the two-layer concrete pavement in just one pass with an output of approximately 400 - 500 m per day.
The first slipform paver was responsible for the subgrade. The 23-cm-thick bottom-layer concrete was paved true to line and level by the SP 1500 L and completely compacted by an internal vibrator, while the SP 1500 L simultaneously embedded dowels and tie bars in it. This yields a homogeneous base for the 7-cm-thick top-layer concrete.
Eurovia GmbH and Wirtgen GmbH have been close partners for many years now. Summarizing the rationale behind the decision, Site Manager Daniel Böhnke said: "The incredible reliability of the machines is a decisive factor for us. Wirtgen's application advice is outstanding. Service technicians are always available without delay in the event that a problem occurs on the job site."
The top-layer concrete is installed immediately after the bottom-layer concrete, so as to ensure optimal interlocking of both layers. The concrete for the top-layer is provided via the bottom-layer concrete paver from a receiving hopper with a charging conveyor and placed in front of the second slipform paver, the SP 1500. The SP 1500 then distributes this material across the entire paving width with its spreading plough, installs the top-layer concrete "wet-in-wet" when passing over it and simultaneously compacts it. The finishing beam and super smoother produce the desired optimum surface finish: during the paving process, a finishing beam is deployed across the roadway while an oscillating super smoother operates in the direction of travel of the paver.