ABSTRACT
Due to the increase of heavy traffic worldwide, many roads are being repaved to be able to support this demand. This generates an ever-growing amount of reclaimed material which is increasingly challenging to recycle due to bitumen aging. A new type of reactive chemical additive (B2Last®), tested at the laboratory of the Institute of Highway Engineering of the RWTH Aachen University, has shown to increase the asphalt performance by creating an elastic network within the bitumen. The additive reacts with the functional groups within the neat and oxidized bitumen producing a good performing bitumen in mixtures with or without reclaimed asphalt. The additive has also shown to increase the workability of the asphalt mixtures, as well as the performance against rutting and fatigue, without disrupting the low temperature behavior. By using softer base bitumen, like a neat 70/100 bitumen, the modified bitumen is able to perform well at very low temperatures, and also at very high ones. This is seen on laboratory bitumen and asphalt tests, as well as on mixture samples taken from the construction of a real-life track close to Munich. There, a 200-meter-long binder layer was built with 50% reclaimed asphalt in June 2019. With a small amount of additive mixed with a neat 70/100 bitumen, the workability on site of the mixture was improved, and the performance was on the same level as the reference track, where an SBS modified bitumen was employed.
