High Resistance Polymermodified Binders to Secure ... - Nynas

Rheometer (BBR) which make it even better to describe the performance related
binder properties.
2. Development of PmB with High Resistance (HR) Properties
Nynas Bitumen developed two grades of High Resistance (HR) polymermodified
binders that are named in the style of the German TL PmB concerning the PmB 25
and the PmB 45.
Both grades the Nypol 25 HR and the Nypol 45 HR have a higher polymer content
based on selected SBS with special additives by using venezuelan base bitumen
which in combination guaranteed the postulated performance. Both grades are of
course cross-linked to guarantee the necessary storage stability especially for higher
polymermodified binders.
2.1 Handling and Storage
The High Resistance PmB’s should be treated as a normal high polymermodified
binder. The delivery and storage temperature is around 180 °C. The HR PmB’s are
stable in storage but for periods of longer than one week the storage temperature
should be lowered to around 140 °C. Reheating should take place gradually, where
possible in a tank with an agitator or with simultaneous pump circulation. The storage
temperature should not exceed 190 °C.
2.2 Mixing and Transport
The asphalt which is made with the HR PmB’s is mixed in the usual sequence where
the temperature of the binder should be around 180 °C. The temperature of the
asphalt mixture should be between 170 °C and 180 °C. The mixture can be stored
briefly in silos provided these are designed to prevent caking at the silo outlet, e.g.
with stainless steel lining and heated silo shutters. The mixture must be transported
that it cools down as less as possible. Covering the mix is absolutely essential.
2.3 Laying, Compaction and Testing
The asphalt mixture made with HR PmB’s should in principle be laid mechanically;
manual laying should be limited to an absolute minimum. The laying temperature
should be around 170 °C. Compaction should take place with heavy static rollers
and / or heavy vibratory rollers, and be completed at a mixture temperature of at least
100 °C.
The HR PmB’s can be extracted from the asphalt mixture with trichloroethylene or
toluene. The extraction time must be extended by at least 30 minutes that all
polymers and additives are reliably dissolved.
2.4 Performance of High Resistance (HR) PmB
The development of the high resistance PmB started with the project of the Container
Terminal in Hamburg (Germany). The tender described the specification for an
special higher polymermodified binder. This project is described in further details in
chapter 3.1.