WR 2500 SK - Soil stabilization and cold recycling
The high-performance soil stabilizer and cold recycler WR 2500 SK converts instable ground into surfaces that are capable of taking high loads, and recycles damaged road pavements to produce extremely durable base layers.
Applications in soil stabilization
Improving the bearing capacity of soils
A chemical process is triggered when lime or cement - or a mixture of these binding agents - is mixed into the existing soil. The process binds the water contained in the soil which causes its compactability to improve and its bearing capacity to increase considerably.
Preparing soils for further processing
Soil stabilization modifies the consistency of the existing soil. Wet, muddy soils are converted into a crumbly mixture that is excellently suited for further processing. This procedure considerably simplifies all further work steps in earth construction.
Homogenizing soils
In backfilling operations, the required quantities of soil are usually quarried in different locations and then transported to the job site where they are dumped. These inhomogeneous soil mixtures are extremely difficult to compact. Wirtgen soil stabilizers are capable of homogenizing such irregular soil mixtures, producing uniformly compactable layers and reducing construction periods at the same time.
Granulating asphalt pavements
The powerful milling and mixing rotors installed in the Wirtgen soil stabilizers and cold recyclers are capable of granulating the entire pavement structure – asphalt layer(s) and gravel subgrade – in one single pass, producing a homogeneous mixture. Following levelling by a grader and compaction by a roller, this mixture is suitable for use as a new subgrade layer. Adding water to the milling operation can significantly improve the compactability of the resulting mix.
Producing hydraulically bound base layers
In the construction of new roads, airports or other traffic surfaces, hydraulically bound base layers are frequently paved on top of the levelled and compacted subgrade. Graded new mineral aggregate is mixed with cement and water to produce the specified material mix.
When Wirtgen stabilizers or recyclers are used to produce the base layer, the mineral aggregate mix is spread on the subgrade level in the specified thickness. The recycler then homogeneously mixes in specified quantities of cement and water in adjacent working cuts. The cement is pre-spread onto the surface ahead of the recycler or directly injected as a slurry into the recycler's mixing chamber. The operation is completed by final levelling and compaction.
Applications in cold recycling
Rehabilitating granular gravel roads
Cold recycling with binding agents is ideally suited for rehabilitating granular gravel roads with poor bearing capacity. The cold recycler scarifies the granular material in adjacent working cuts, recycling it at the same time by adding binding agents and water. The recycling operation is completed by final levelling and compaction, producing a bound material layer with significantly improved bearing capacity.
Recycling damaged roads with cement
Mixing cement into a granulated blend of asphalt and gravel results in a highly stable construction material that meets the requirements of a hydraulically bound base layer.
The existing road pavement is milled and granulated by the mobile recycler in a single working operation, while cement and water are mixed in simultaneously by the machine's milling and mixing rotor. The recycling operation requires neither the source material nor the recycled construction material mix to be transported. Depending on the type of cold recycler used, the recycled material is placed by a paving screed integrated into the recycler or by graders and rollers.
Recycling damaged roads with bitumen emulsion
Bituminous bound base layers can be produced by mixing bitumen emulsion into a granulated blend of asphalt and gravel material.
Bitumen emulsion and water are injected into the recycler's mixing chamber and mixed with the granulated material during the milling operation. Depending on the recycler used, the recycled material is either placed by a paving screed integrated into the recycler or by graders and rollers.
Recycling damaged roads with foamed bitumen
Bitumen foam is produced by adding water to hot bitumen just prior to injecting it into the cold recycler's mixing chamber, increasing its original volume many times.
Bituminous bound base layers of superior quality can be produced by mixing foamed bitumen into a granulated blend of asphalt and gravel material.
Recycling damaged roads with foamed bitumen and cement
Bituminous/hydraulically bound base layers of superior quality are produced by mixing foamed bitumen and cement into a granulated blend of asphalt and/or gravel material.
The cement is either taken from the integrated silo and pre-spread on the surface ahead of the cold recycler, or is delivered as a slurry from the slurry mixer and injected directly into the cold recycler's mixing chamber.
