High Resistance Polymermodified Binders to Secure ... - Nynas

3.2 Application Example Bus Station
Due to the good experiences of the high resistance PmB the Nypol 25 HR was also
used for the remediation of several areas of the bus station in Hamm (Germany). The
old areas made out of asphalt around the central platform had huge deformations
and had to be rehabilitated.
The old asphalt binder course and the old stone mastic asphalt were participating in
the huge deformations. The optical impression of the whole Bus Square should not
be changed, i.e. other constructions like concrete or composite pavement structures
was not possible. The rehabilitation had to be done in an asphalt construction. After
milling of the both old layers a new construction with binder course asphalt 0/22 S
and with stone mastic asphalt 0/11 S by using the Nypol 25 HR was build. In the
following table 4 the results of the wheel tracking tests are shown. The results are
extremely good compare with the German limit of 3,5 mm for binder courses. The rut
depth for the surface course is below 1,0 mm.
Table 4: Results of German Wheel Rutting Test – Nypol 25 HR (Steel Wheel at 50 °C)
Binder Course
Asphalt 0/22 S
Stone Mastic
Asphalt 0/11 S
Binder Content
[M.-%]
Air Void Content
[Vol.-%]
Rut Depth at 50 °C
[mm]
4,2 6,3 2,2
6,8 4,2 0,8
The paving of the asphalt mixtures were made with a conventional paver by using a
9,5 t smooth-wheeled vibration roller. The compaction was controlled with a Troxler
probe. Due to the good workability of the HR PmB paving temperatures between 160
and 170 °C were used without any problems for the compaction of the asphalt
mixture. The demand compaction degree of 97 % was achieved. The laying was
done during the hot summer period in August 2004. Referring to this the Bus Square
was closed for three days to guarantee the cooling down. On Monday morning the
bus traffic started again.
4. Conclusions
Based on the experiences of the high resistance high polymermodified binder is
resulting that with the Nypol 25 HR and the Nypol 45 HR two binders are available
which are able to ensure durable asphalt pavement for different applications.
The range of plasticity of these high resistance binders amounts nearly 100°C. The
heat stability amounts more than double measured by complex shear modulus and
compared with a standard PmB. The behaviour at low temperatures is not affected
measured with the Bending Beam Rheometer. The asphalt performance for binder
course asphalt and stone mastic asphalt tested with the wheel-rutting tester (steel
wheel at 60°C) is exceptional well.
5. References
Barth, R.: Das Nynas - Spezialbindemittel für sehr hoch beanspruchte Verkehrsflächen,
Performance, Issue 3, 2003