A binding agent offering lots of potential
Cold recycling with foamed bitumen has become an established technology worldwide and is now increasingly moving into the focus of road authorities and construction companies for use in the rehabilitation and new construction of road pavements. Cold recycling with foamed bitumen produces flexible and highly durable base layers. Being a part of the pavement structure, these are the perfect foundation for the final asphalt overlay to be built at reduced layer thickness. Foamed bitumen is produced from approx. 175 °C hot road-grade bitumen using state-of-theart technology. Microprocessor-controlled injection systems installed in the WIRTGEN recyclers produce the foamed bitumen and inject it into the mineral aggregate in precisely metered quantities.
The perfectly engineered process impresses with:
- exceptionally high durability of layers
- economic viability
- saving of natural resources
- reduction of CO2 emission
- reduction of construction times.
Producing foamed bitumen
Foamed bitumen is produced by foaming standard road-grade bitumen. In the process, small amounts of water and air are injected into the hot bitumen at high pressure, which results in the bitumen foaming and expanding to around 20 times its original volume. The bitumen foam is then injected into a mixer via injection nozzles. It is eminently suitable for mixing with cold and moist construction materials. The new material – frequently produced using reclaimed asphalt pavement (RAP) – is called BSM (bitumen - stabilized material).