Bitumen rubber is globally known to be the best modified binder from a
rheological and a durability perspective. Due to its visco-elastic properties, the product must
be handled at very high temperatures (relative to other binders used in similar applications)
and it has a limited shelf-life at these elevated temperatures. Despite the excellent
performance of the bitumen rubber product, it is often disregarded as a result of the
complexity of the operation and the risk associated with the product. These concerns can
be addressed by lowering the handling and application temperatures. The integration of a
warm mix wax additive in bitumen rubber manufacturing, allows for lower handling and
application temperatures. This is aligned with the global focus on the reduction of
temperatures during asphalt manufacturing and paving, to improve worker health and safety,
while reducing the carbon footprint. A “stabilized warm mix rubber asphalt binder” that
can be produced at reduced temperatures with an increased stability over time is now
possible with the use of innovative compounds of ground tyre rubber, swelling agents and
warm mix wax additives. The combination of a Fischer-Tropsch wax additive and a
swelling agent decreases the viscosity of the reacted binder significantly and improves the
handling and compaction behaviour of the asphalt mixes. It further allows lowering the
production and paving temperatures from ~200°C to ~160°C. This rubber compound
technology overcomes current drawbacks of rubber modified asphalt enabling the use of this
technological to deliver environmentally beneficial pavements.