Asphalt recycling is a core component of resource-efficient road construction. With the increasing use of rubber-modified binders (RmB G), the question arises as to how this technology can be recycled and combined with reclaimed asphalt pavement (RAP) – both from a technical and ecological perspective.
Rubber-modified asphalts produced, for example, with CTS GRM in accordance with TL RmB-StB By can be recycled in the same way as conventional asphalts. In several projects in Germany and Austria, asphalt containing RmB G has been successfully milled, processed, and reused.
Compared to conventional or polymer-modified mixtures (PmB), rubber-modified asphalt offers a significantly longer service life and slower aging. As a result, part of the original binder functionality remains intact even after the material has been reclaimed.
Recyclability is supported by the long-chain polymer network structure within the rubber. Unlike PmB, the elastomeric components in RmB G do not break down into smaller molecules, but retain their structure over time.
Technologically, reclaimed asphalt containing RmB G can be reused in new asphalt mixtures without limitations. The reclaimed content even benefits from the high aging resistance of RmB G – recycled mixes containing rubber-modified bitumen are also more resistant to heat during production. The material can be processed into new asphalt mixes across all layers – base, binder, and even surface courses such as AC and SMA.
One key advantage of RmB G over PmB is that the degree of modification is based on the total binder content, not just the added fresh binder. This ensures consistent modification levels, even with fluctuating or high RAP content – a clear benefit for quality control during production. In summary, when producing asphalt with high reclaimed content (>20%), RmB G offers a substantial technical advantage:
In practice, this means: regardless of the RAP content, the required modification level is always maintained when using RmB G.
According to an independent life cycle assessment by Umtec AG, RmB G outperforms PmB in all three assessment categories – binder production, asphalt production, and full life cycle. Especially when looking at CO₂ emissions per installed ton per year, the following savings can be achieved using RmB G:
These figures reflect both the extended service life and the substitution of primary bitumen through the use of recycled rubber from end-of-life truck tires.
The combination of RmB G and reclaimed asphalt presents a technically robust and ecologically sound solution for modern road construction. The reuse of rubber-modified recycled asphalt is both feasible and easily integrated into existing mixing operations. At the same time, RmB-G-based asphalts enable more sustainable infrastructure through longer service life, improved aging resistance, and high cold flexibility – all while reducing environmental impact.
