High Resistance Polymermodified Binders to Secure ... - Nynas

Dr.-Ing. Ingo Nösler
Product Support Manager Central Europe, Nynas Bitumen, Belgium
High Resistance Polymermodified Binders
to Secure Durable Asphalt Pavements
Summary
New high polymermodified binders with high resistance properties will be presented.
These special binders have additionally a viscosity-reduced performance that allows
a good workability and compaction. The new high resistance polymermodified
binders are especially developed for asphalt pavements with high and static traffic
loading like junction areas, roundabouts, traffic jam areas, bus stations, high gradient
roads, container terminals, etc.
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.
This paper is describing these special high resistance polymermodified binders and
their possibilities of usage to ensure durable asphalt pavements. Furthermore the
paper is giving recommendations for special applications, experiences and examples
from German high traffic loaded areas.
1. Introduction
Static and high loading in addition with high temperatures are the worst mode of
loading for asphalt pavements. In such cases permanent deformations are preprogrammed.
The resistance to permanent deformations could be improved by using
harder binders but mostly as a consequence of other performance related properties
like durability and cold behaviour are decreasing.
For such a special asphalt pavements with high and static traffic loading like junction
areas, roundabouts, traffic jam areas, bus stations, high gradient roads, container
terminals, etc. new high polymermodified binders with high resistance properties are
necessary. The target was to develop special high polymermodified binders to
ensure durable asphalt pavements who should have additionally a viscosity reduced
performance that allows a good workability and a good compaction.
In the German delivery specification of polymermodified binder (TL PmB, issue 2001)
is one high polymermodified binder specified. Concerning the PmB 40/100-65 H the
target of the new development of the special PmB was to increase the stability of the
asphalt pavement to ensure durable pavements in addition of an increase of the
workability. With this context the property of the cold behaviour should be the same
or even better. The TL PmB also include volunteer additional test values like the
Dynamic Sheer Rheometer (DSR), the Force Ductility (FD) and the Bending Beam

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.

In the table 1 is shown the tender specification in comparison to the new developed
high resistance PmB – Nypol 25 HR. Typical applications for Nypol 25 HR are heavy
duty industrial areas such as port unloading areas, container terminals or traffic areas
with high static loading such as truck parks and bus stations. Nypol 25 HR is used in
stone mastic asphalt, asphalt concrete and asphalt binder course for extraordinary
loading.
Furthermore you can see the properties of the high resistance PmB Nypol 45 HR
which was developed for the application of asphalt mixtures for heavy duty traffic
areas such as road class up to SV, junction areas, roundabouts, traffic jam areas,
bus stations, high gradient roads, etc.
2.4.1 Performance Testing of High Resistance (HR) PmB
For the behaviour at low temperatures the stiffness at -16 °C [Mpa] was measured by
using the Bending Beam Rheometer (BBR) in the style of the description of
AASHTO TP1-97. The Force Ductility (FD) at 25 °C was measured in the style of the
description of TL PmB – Appendix B. For the deformation behaviour the Complex
Sheer Modulus G* and the Phase Angle δ was measured at 60 °C by using the
Dynamic Sheer Rheometer (DSR) in the style of the description of AASHTO TP1-97
with the test conditions as follows:
Frequency: 1,59 Hz
Plate Diameter: 25 mm
Plate Gap: 1 mm
Deformation: 0,05 mm
Temperature Control: Water Bath
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.

Table 1: German specification for PmB deliveries (TL PmB, 2001) in comparison with
different higher polymermodified binders
Properties Unit
TL PmB
40/100-
65 H
Method
DIN EN -
Nypol
25 HR
CT - Tender
Specification
Nypol
45 HR
Penetration (100 g, 5 s, 25°C) mm/10 40 – 100 1426 10 – 35 60 – 80 20 – 50
Softening Point Ring and Ball °C ≥ 65,0 1427 85 – 100 85 – 105 75 – 85
Breaking Point Fraass °C ≤ -15 12593 < -5 < -16 -10
Ductility at 25 °C cm ≥ 60 DIN 52013 > 30 > 100 > 50
Elastic Recovery at 25 °C % ≥ 70 13398 > 70 > 90 > 50
Storage Stability
Different of Softening Point
Change of Softening Point
after Ageing (RFT)
– Increase
– Decrease
Change of Penetration after
Ageing (RFT)
– Remaining
– Increase
Ductility at 25 °C after
Ageing (RFT)
Elastic Recovery at 25 °C
after Ageing (RFT) at 20 cm
String Length
Behaviour at Low
Temperatures
Bending Beam Rheometer
(BBR)
- Stiffness at – 16 °C
Force Ductility (FD) at 25 °C
Deformation Behaviour
Dynamic Sheer Rheometer
(DSR) at 60 °C
- complex Sheer Modulus G*
- Phase Angle δ
°C ≤ 2,0
°C
°C
%
%
≤ 8,0
≤ 5,0
≥ 60
≤ 10
cm ≥ 30
%
≥ 50
13399 &
1427
12607-3 &
1427
12606-3 &
1426
12607-3 &
DIN 52013
12607-3 &
13398
< 2,0 < 2,0 < 2,0
< 8,0
< 2,0
> 60
< 10
< 6,0
< 8,0
> 60
< 10
< 8,0
< 2,0
> 60
< 10
> 20 > 40 > 30
> 60
Additional Volunteer Requirements and Test Methods
MPa
J
Pa
°
≤ 200
≥ 1
≥ 3500
≤ 75
AASHTO -
TP1
TL PmB –
Appendix B
AASHTO -
TP 5
390 2)
< 400
1,9 2)
> 1
66.000 2)
60 2)
> 30.000
< 65
< 70 1)
138 2)
0,3 2)
4.750 2)
57 2)
> 50
175 2)
< 300
> 1
16.000 2)
64 2)
> 10.000
< 70
CT – Tender Specification: For the tender of the Container Terminal Hamburg required
properties of the higher polymermodified binder that was
advertised for the bid
1) With 10 cm String Length 2) Typical Values

3. Application of High Resistance Polymermodified Binders
The following chapters describing more detailed the practical application of the
developed high resistance PmB’s. Already in the Saison 2003 both high resistance
PmB’s, i.e. Nypol 25 HR and Nypol 45 HR, where used for several constructions
which where stressed by high and static traffic loading and where a durable asphalt
pavement are postulated. The HR PmB’s was used for asphalt binder courses 0/16 S
and 0/22 S, for asphalt concrete 0/11 S and for stone mastic asphalt 0/8 S and
0/16 S. Two of these examples will be described in the following chapters.
3.1 Application Example Container Terminal Hamburg
The container handling of the harbour of Hamburg had a growth last year with more
than 10 percentage and is as a consequence the number one in Europe. More than 3
million containers were unloaded. Laid one after another would be a line from the
North Pole to the South Pole.
For the upgrading of the container handling in the harbour of Hamburg the Container
Terminal Altenwerder is building up to the end of 2004. It is more than self-evident
that the client is expecting a durable asphalt pavement. The demand of the client
concerning the pavement design looks as follows:
200 Van-Carrier
Axle Loading: 125 kN/day
365 days/year
Total Usage: 20 years
With the above mentioned input for the pavement design resulted the following
pavement construction by using a special high polymermodified binder:
30 cm – Gravel Roadbase 0/45
8 cm – Asphalt Binder Course 0/16 S
6 cm – Stone Mastic Asphalt 0/16 S
The grading curve of the used asphalt binder course 0/16 S is shown in the figure 1.
Figure 1: Binder Course Asphalt 0/16 S – Container Terminal Hamburg

3.1.1 German Wheel Tracking Test
The German Wheel Tracking test is used to measure in the laboratory the resistance
against deformation and stripping of the binders on compacted asphalt samples.
Asphalt plates can be tested dry or under water with loaded steel or rubber coated
wheels. The test conditions are shown in the documentation (TP A StB).
The test is mainly used for extended qualification tests and as a tool for development
of improved mix formulations or development of improved bituminous binders. Great
experience is based on asphalt binder mix formulations measured normally at 50°C
under water with a steel wheel. A principal drawing of the test arrangement is shown
in figure 2.
loading: 700 N
20.000 wheel passes
test wheel
∅ 20,3 cm / width 4,7 cm
drive wheel
specimen
26 x 32 x 5 cm
Figure 2: Principle of the German Wheel Tracking Test
water bath
In the German Wheel Tracking Tester two asphalt specimen of 260 x 320 x 50 are
tested simultaneously. The steel wheels charge the specimen with a load of 700 N.
The results are indicated as vertical movement of the wheels in dependence of the
number of passes. They are graphically shown as the mean of the two samples.
Normally the results after 20.000 wheel passes are stated. The speed of the test
wheels is 53 min -1 . The test is terminated earlier when a maximum rut depth of 20
mm is reached.
For the compaction of the test plates a Linear Kneading Compactor was used. This
compactor has shown good correlation with field compaction. The calculated amount
of asphalt is weighed and put into a metal mould of 260 x 320 mm. Steel lamellas of
100 x 10 x 260 mm are placed on top of the uncompacted sample in the mould. The
necessary amount of asphalt is calculated on basis of the bulk density of a Marshall
Test Specimen. By help of a hydraulic press a steel wheel is progressively lowered
until the steel lamellas are even with the upper border of the mould.
The table 2 shows the exceptional well results of the wheel-tracking test. The test
was done at 60 °C (because the values for 50 °C were too small) water temperature
and with a steel wheel. Both values for the used asphalt mixture 0/16 S are below 2
mm. The German limit for binder courses is below 3,5 mm. In comparison with the
Nypol 25 HR you can see in table 2 the results of the higher polymermodified binder
that was advertised for the bid from the tender of the Container Terminal Hamburg.
For the mixture of the binder course it is similar the same behaviour. For the stone
mastic asphalt the Nypol 25 HR reach a better result of roughly 30 percentage.

Table 2: Results of German Wheel Rutting Test – Nypol 25 HR (Steel Wheel at 60 °C)
Binder Course
Asphalt 0/16 S
Stone Mastic
Asphalt 0/11 S
Stone Mastic
Asphalt 0/16 S
Binder Content
[M.-%]
Air Void Content
[Vol.-%]
Rut Depth at 60 °C
[mm]
Rut Depth at 60 °C
Tender Product [mm]
4,2 5,2 1,7 1,6
7,1 3,7 2,5 ---
5,2 3,7 1,4 2,1
3.1.2 German Compactability Test
By using high polymermodified binders with high resistance properties mostly as a
consequence of the higher softening point the workability of the final asphalt mixture
is decreasing. To counteract this negative property the high resistance PmB’s
including a special viscosity reduced additive that allows a good workability and a
good compaction.
To quantify the good workability and the good compactability the German compactability
test was done for the asphalt binder course 0/16 S and the stone mastic
asphalt 0/16 S. The compaction resistance was measured in the style of the German
test description by using Marshall specimen. At this the compaction resistance is
quantify by measuring the change of the thickness of the specimen in dependence
on the compaction work. For this 100 compaction blows on each specimen side is
used by measuring the change of the specimen thickness. In figure 3 you can find
the result for the asphalt binder course 0/16 S by using the Nypol 25 HR.
Figure 3: Evaluation of the Compactability – Asphalt Binder Course 0/16 S by using
Nypol 25 HR

The value D for the compaction resistance is resulting from the iteration calculation of
the exponential function of the compaction. The function is build with the decreased
thickness of the specimen in connection with the number of blows. The figure 4
shows the result for the stone mastic asphalt 0/16 S by using the Nypol 25 HR.
Figure 4: Evaluation of the Compactability – Stone Mastic Asphalt 0/16 S by using
Nypol 25 HR
In comparison with the Nypol 25 HR you can see in table 3 the results of the German
compactability test from the higher polymermodified binder that was advertised for
the bid from the tender of the Container Terminal Hamburg. For the mixture of the
binder course it is again similar the same behaviour. For the stone mastic asphalt the
Nypol 25 HR reach a better result of roughly 10 percentage for the compactability
and out of it for the workability.
Table 3: Results of German Compactability Test – Container Terminal Hamburg
Binder Course
Asphalt 0/16 S
Stone Mastic
Asphalt 0/16 S
Compaction Resistance D [21 Nm]
Nypol 25 HR
Compaction Resistance D [21 Nm]
Tender Product
40,6 40,4
37,7 41,1

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