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application notes & technical articles
What Happens When Rheological
Properties Change?
Looking into rheological properties with simultaneous
collection of microscopic images
To gain information about the
reasons for certain changes in
rheological properties, a new
special module for the HAAKE
MARS has been developed.
biennial 07-08
polymer industries
food industries
pharmaceutical, cosmetic
& allied industries
chemical & allied industries
surface coatings industries
It combines a temperature control unit for
cone/plate- and plate/plategeometries
with a state-of the- art microscope. The
RheoScope module is presented and example
data from different applications is shown.
Rheology is a”macroscopic“method, which tells
us how a material behaves under given conditions
but never tells us why. For an understanding
about the reasons why a certain behaviour
occurs, we need to combine rheology with a
“microscopic method“ able to look into the
structure of the material.
Examples for such techniques complementing
rheological measurements are GPC, thermal
analysis, (FT)IR or microscopy. Running two
independent measurements on different
instruments, however, doubles instrument time
application notes & technical articles
Rheological Characterisation
of Asphalt Binders
construction &
building industries
The bitumen binders used in
asphalt are playing a crucial
role for the performance of the
asphalt.
Today, 25% of the binders are polymer modified
bitumen (PmB), providing a more sophisticated
performance and a wider temperature range than
pure bitumen does. The future share of PmB is
likely to grow due to environmental regulations,
due to a higher quote of recycling asphalt and
due to requests for lower temperature processing
e.g. for air port run ways.
A first world-wide applied standard for asphalt
binders was determined in the US Strategic
Highway Research Program (SHRP) which was
started in 1987. The results were published in
1993, standardizing for rheological testing a
Dynamic Shear Rheometer (DSR) to investigate
and predict the fatigue behaviour (4°C and 40°C)
and the behaviour at elevated temperatures
(46°C and 82°C) with a steady state stepped
temperature profile with steps of 6 degrees –
corresponding to the performance grades.
Moreover, the processability of the binders is
tested at 135°C with a rotational viscometer or
rheometer.
In order to achieve the standard compliant
temperature accuracy of ± 0.1 deg
or better, particular SHRP temperature control
and measuring time and often leaves a bit of a
doubt whether the sample and its treatment
before measuring have been exactly the same.
The double effort of time and resources can be
avoided by running two different methods on the
same sample simultaneously, testing its
macroscopic and its microscopic properties. The
two resulting data sets can easily be correlated
since they have been collected at the same time
on the same sample.
A complete copy of this application note is
available by requesting V-228
units were designed in the 1990s (Fig.2). Today,
more and more measurements are made with
Peltier temperature control units, e.g. for the
screening of differently modified PmBs. The
Peltier temperature control units provide a wider
temperature range – also facilitating the relevant
sub ambient temperatures.
When bitumen or PmB is subjected to cooling, it
shows exceptionally strong shrinkage leading to
higher forces than the already high forces that
are brought about by shrinking thermoplastics.
The shrinkage of asphalt binders may lead to
quality issues and it is therefore of interest to
determine the occurring normal force and the
shrinkage in micrometers.
A complete copy of this application note is
available by requesting V-225
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