Remix Plus at the foot of the Rhine Terraces.
On the section between the towns of Mettenheim and Alsheim, the surface course of the B9 federal road displayed severe cracking, which had been caused by traffic loads and weather influences. Rehabilitation of the surface course was to be carried out using the economically efficient, fast and environmentally friendly Remix Plus method. The 12.20 m wide pavement was recycled in several adjacent cuts. One lane each in both the working direction and the opposite direction were kept open to traffic all the time.
The recycling train was headed by the first of three HM 4500 heating machines from Wirtgen which heated the existing surface course to between 120°C and 150°C. The pavement was heated with an overlap, thus ensuring a seamless bond between adjacent cuts.
A chip spreader travelling immediately behind the first panel heating machine from Wirtgen added supplementary chippings to ensure that the specified gradation would be achieved after completion of the remixing operation. In the recycler’s mixer, the heated and scarified material of the old surface course was mixed with the chippings to a new binder course that was then paved by an integrated levelling screed.
A truck travelling behind the panel heating machines and the chip spreader delivered 180°C hot stone mastic asphalt into the recycler’s receiving hopper, from where it was transported to a second paving screed via heated charging conveyors. Batches of 28 tons of paving mix guaranteed a continuous material flow. The Remixer 4500 from Wirtgen used the mix to apply an additional thin layer of stone mastic asphalt on top of the binder course produced from the recycled surface layer. The Remix Plus operation created a remixed binder course with a layer thickness of 5 cm, and an asphalt surface course consisting of 3 cm of virgin stone mastic asphalt.
When the new asphalt surface course had cooled down to around 100°C, it was compacted by rollers, and chippings were applied in a final work step to improve the pavement’s skid resistance. The section of road was opened to traffic as soon as the asphalt had cooled down.
|Job site:||B9 federal road between Mettenheim and Alsheim, Germany|
|Project length:||approx. 3 km|
|Project width:||12.20 m|
|Paving material:||stone mastic asphalt|