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Sasobit - A Globally Recognized, High Performing Asphalt Additive
Since 1997, 20 million tons of Sasobit modified asphalt has been used
globally in a variety of diverse pavement projects ranging from dense
and open graded mixes, stone mastic asphalt, Gussasphalt, and RAP projects
to rubberized asphalt concrete.
Sasobit is a unique, cost effective and environmentally friendly asphalt
additive. Unique properties inherent to Sasobit promote increased use
of the higher performing PMA blends by easing the mixing/application
process through reduced viscosity. The advantage of lower plant mixing
temperatures offers both energy cost savings and reduced GHG emissions.
These qualities make it a popular choice among leaders in the road paving
and maintenance industry.
Sasobit has been used in such demanding applications as:
- Interstate Highways
- Airports, including one in Svalbard
- Container Ports
- Race tracks
- Long haul projects
Extremely positive feedback has been received from academics, contractors,
engineers, DOT and FHWY officials and workers at both HMA plants and
in the field with no reports of failure.
Warm Mix Asphalt - The Green Alternative
Sasobit is especially suited for warm-mix asphalt (WMA). This technology
is used to lower the production temperatures of hot-mix asphalt (HMA).
The benefits of using Sasobit in WMA are numerous and
include:
- Lower plant mixing temperatures, from 300 °F to 250 °F,
allows for up to a 19% fuel cost savings to the contractor.
- Lower mixing temperatures at the plant leads to a
reduction
in emissions
which in turn leads to a reduction in overhead costs
related to emissions control.
- Lower mixing temperatures will minimize oxidative
hardening of the asphalt and this will lead to reduced thermal
cracking of the pavement and potentially a longer lifetime.
- When produced at normal temperatures longer haul
distances, as well as a longer
construction season become possible.
- Lower emissions during the paving operation provide a
healthier
work environment
for the contractors and the neighborhood in case
of a residential project.
- Sasobit is versatile, safe
and is easily blended into the binder at the terminal or into
the mix at the Hot Mix Plant.
The Use of Sasobit in RAP
The use of Recycled Asphalt Pavement (RAP) has gained
a tremendous boost by using Sasobit. Some of the key advantages are:
- The unique viscosity reducing features of Sasobit along
with the internal lubricating effects can allow for new areas
of RAP usage and easier handling of RAP mixes.
- RAP usage can be increased dramatically
to 35%, 45% or even more with superior compaction.
- Sasobit can decrease the temperature by
which RAP is used. In Maryland the temperature was decreased from
350° F to 275° F using 35% RAP.
- Sasobit in RAP reduces the problem of achieving the required
density by reducing the compaction resistance of
the RAP mix.
The Chemistry Behind Our Success
Sasobit is a crystalline, long chain aliphatic polymethylene hydrocarbon
produced from natural gas using the Fischer-Tropsch (FT) process. The
carbon chain length ranges from C45 to C100
plus.
By comparison, macrocrystalline bituminous paraffin waxes have carbon
chain lengths ranging from C25 to C70.
The unique properties of Sasobit are high melting point, low melt viscosity
and high crystallinity (hardness). These properties are used to great
effect to modify asphalt:
- Chemical structure – Sasobit is identical to paraffin
waxes that are found in crude oil, except that it has a higher molecular
weight. Therefore, it dissolves easily into asphalt at temperatures
above 248° F and will not separate out on storage.
- High melt point – when added to softer grades of asphalt,
there is no bleeding that is associated with low molecular weight
waxes. This provides the possibility to upgrade softer grades of asphalt.
- Low viscosity – Sasobit is used as an asphalt flow improver,
both during the asphalt mixing process and during laydown operations.
The dramatic reduction in viscosity obtained by adding Sasobit to
asphalt at working temperatures makes the asphalt easier to process,
provides the option of reducing working/mixing temperatures and thereby
reducing fume emissions, saving energy and reducing production cycles.
This is why Sasobit is the preferred additive for warm-mix asphalt
(WMA).
- High crystallinity and hardness – Sasobit is used as
a binder modifier to produce rut resistant mixtures. It offers an
alternative to SBS modification when increased stiffness to prevent
rutting is required. It can be added in combination with SBS to produce
a binder which is stiff, but also offers some of the elastic benefits
of SBS.
The following links will provide further information on the evaluation
of and projects where Sasobit was used:
Sasobit® Sales Manager by Region
United States
Sasobit® Product Information: |
