Cold In-Plant Recycling

A Mobile Cold Recycling Mixing Plant (KMA) Saves Time and Cuts Costs

In cold in-plant recycling, a mobile cold recycling mixing plant (KMA) is set up close to the construction site. The materials to be recycled are brought to this plant by truck, processed, and transported back to the construction site by truck as a high-quality finished product and directly used for paving. This approach is popular in road construction, but is also possible in demolition recycling. The process makes good financial and environmental sense because the short distances between the construction site and the cold recycling mixing plant save time, money, and reduce truck mileage. Various machines and plants from theWirtgen Group work together in the cold in-plant recycling process.

Efficient Recycling of Demolition Wastes and Reclaimed Asphalt Pavement

When a building is demolished, for example, the concrete rubble can be recycled. Within this process, synergies are unlocked between the Kleemann and Wirtgen plants. First of all, the concrete must be crushed. There is often a challenge to overcome in this regard, however: reinforced concrete. With reinforced concrete, you often don’t know exactly how hard the concrete is and how much steel it contains. This can push many crushers to their limits.

MOBIREX mobile crushers from Kleemann are ideal crushing solutions on a cold in-plant recycling site.

The MOBIREX MR 130 Z EVO2 from Kleemann is suitable for such uses. The mobile impact crusher has an optimized inlet geometry for better feed characteristics. In addition, the crusher inlet flap, which can be raised hydraulically, and the upper crusher impact swing arm prevent jamming at the entrance to the crusher unit. At the same time, the sensors of the Continuous Feed System (CFS) ensure optimum filling of the crushing chamber.

Time-Saving Process Between Demolition and Paving

Overload protection shields the crushing unit from large metal parts such as T-beams. Sensor-controlled hydraulic cylinders allow the impact swing arm to move back when an unbreakable part enters the crushing chamber. The metal part is diverted and transported to the crusher discharge belt, which can be equipped with an optional magnetic separator. The electric or permanent magnet attracts the metal part and throws it to the side so that the crushed concrete is fed into the secondary screening unit without reinforcement.

The secondary screen sorts the crushed concrete into different grain sizes. Oversize material is returned to the crusher unit via the oversize material return belt in a closed loop. All of the MOBIREX MR 130 Z EVO2’s functions can be controlled via the simple and intuitive SPECTIVE control concept. For example, the crushing gap can easily be adjusted to the desired size by touch screen control – even when the rotor is running. It couldn’t be any easier or safer.

The concrete aggregate with the desired gradation is then fed into the Wirtgen KMA 240 with a wheel loader or directly from the crusher. The cold recycling mixing plant mixes the concrete with binding agents and water to produce a high-quality final product, e.g. for a hydraulically bonded base layer that can then be immediately used for repaving. Due to the mixing location in the immediate vicinity of the demolition site, not much time passes between demolition, cold in-plant recycling, and paving.

Typical application: an example of road rehabilitation with cold in-plant recycling

Even more machines from the Wirtgen Group can be used in combination in road construction. During road rehabilitation, the layers in need of rehabilitation can be milled out with a Wirtgen milling machine. The materials removed by milling are then transported by truck to the mixing site near the construction site. These reclaimed materials are then processed in a Kleemann impact crusher on the mixing site. The reclaimed material is transported by a Deere excavator or wheel loader to the crushing plant, where it is crushed down to the required aggregate size.

The cold recycling mixing plant can be fed either by a John Deere wheel loader or directly from the crusher.. In the (KMA) cold recycling mixing plant, the reclaimed material is mixed with water and binding agents such as foamed bitumen, bitumen emulsion, or cement. The cold mix is then transported back to the construction site, where it is paved using a Vögele paver. Last but not least, the surface is compacted by a Hamm compactor. This how the Wirtgen Group machines and plants ideally complement one another in the road construction process chain. When one machine or plant stops, the next begins its work – delivering perfect results from a single source.