A Better Way to
produce polymer modified hot mix asphalt paving...
Did you know that polymer
modified and high quality SHRP PG grade asphalt cements can be produced
at the Contractor's plant easily, efficiently and economically?
It is as simple as injecting
latex, a dispersion of microscopic polymer particles in water, into the
asphalt cement line just before it discharges into the drum. The water
in the latex flashes off into the drum, leaving the polymer particles dispersed
into the asphalt cement. Due to the microscopic particle size, the polymer
disperses rapidly to form a swollen network of long polymer chains tangled
throughout the asphalt matrix.
The PLUS™ Advantage
Whether you're a Highway
Engineer or a Paving Contractor, the PLUS Advantage is for you. It's guaranteed
to change the way you look at polymer modified asphalt.
But what is it? The Post-added
Latex Utilization System (PLUS) is the method
of producing polymer modified asphalt by adding polymer in the form of
styrene butadiene (SBR) latex at the Contractor's hot-mix plant. High quality
SHRP PG and polymer modified asphalts can be produced from readily available
asphalt by utilizing SHRP PLUS specifications developed by Rub-R-Road.
The PLUS method offers Engineers a highly reliable way to specify and monitor
polymer modified asphalt quality. The PLUS method offers Contractors a
simpler way to produce and handle polymer modified asphalts. Both Engineers
and Contractors will enjoy cost savings that translates into more value.
Selecting the right asphalt
cement for the job can be critical to your project's success. Whether you
specify a high quality SHRP PG or polymer modified asphalt cement for the
binder in your pavement you should consider the use of SBR latex.
Specifying the PLUS method
of producing high quality asphalt binders provides DOTs, Cities and Counties
added value to their asphalt paving programs. Adding SBR latex to asphalt
pavements has been proven to dramatically enhance quality and long-term
performance. As recently as November 2000 an article entitled “Asphalt
is the Perpetual Pavement” appeared in the Asphalt Contractor magazine.
In the article a paving contractor was given The Master Craftsman Award
for the superior performance of a 19 year old interstate pavement. The
pavement contained Rub-R-Road R-504 SBR latex compound that was cited as
the "secret ingredient." The contractor was quoted as saying, ”I think
that's (the SBR latex) the reason for it holding together.”
Aside from the proven long-term
performance record of SBR latex modified hot-mix asphalt pavements, why
should you go to all the effort to rewrite specifications to include SBR
latex? After all, you're busy.
We know you're busy. Rub-R-Road
has over fifty years of experience with polymer modified asphalt cements
and will assist you to write fair, competitive specifications. That's right,
specifications that allow for fair competition for paving contractors and
asphalt suppliers. Contractors are pleased to accept more control and responsibility
for their work given the opportunity to use SBR latex for asphalt modification
at their plants. Asphalt cement suppliers that do not provide high quality
SHRP PG or polymer modified asphalts will be able to compete for sales
currently unavailable to them. These market forces will provide your agency
with added value for every dollar spent for paving.
Adding latex at the contractor's
hot mix plant is easy for both drum and batch plants. Rub-R-Road has the
products, equipment and the know-how to insure their success.
The process is simple. In
a drum plant the latex is injected into the asphalt cement line just prior
to the mixing drum. In a batch plant the latex is added to the pug mill
during the mixing cycle.
Quality assurance is simple
too. Rub-R-Road has developed pumping and metering equipment which accurately
adds the polymer to the asphalt and provides a data print out of its addition.
DOTs can use this information to verify compliance with specifications.
In drum plant operations a sample of the modified asphalt cement can be
obtained for additional verification, if required. Adding the polymer at
the contractor's plant has the added benefit in that the polymer content
can be verified and the polymer is not subjected to long exposure to excessive
heat that can cause the polymer to deteriorate.
Contractors realize cost
savings too. They are not dependent upon asphalt cement vendors which supply
polymer modified asphalt. Typically contractors can use the “regular” grade
of asphalt cement to make high quality SHRP PG and polymer modified asphalts.
There is no need for additional agitated hot asphalt cement tanks to hold
the extra grades of cement required to meet various production schedules.
This can be extremely important to contractors with bulk asphalt cement
terminals. Rub-R-Road offers these contractors the ability to become more
vertical in their supply chain.
Contractors, what does this
mean when it comes time to bid on your next project?
Utilizing the post addition
method of adding latex provides you a valuable option. This option make
it possible for you to best utilize the capabilities of your plants to
meet all your various production schedules without incurring any significant
additional expenses. When you produce your own high quality SHRP PG or
polymer modified asphalt by means of adding latex you can use the same
asphalt cement for several projects currently in production by merely turning
on or off the latex supply. This flexibility will make it possible for
you to bid more aggressively on more work while providing the motoring
public with higher quality materials.
Many contractors report that
adding latex at their hot mix plant gives them more control of their final
mix product. “We know how much (polymer) is in there and when it was mixed.”
Contractor experience and
testing using SHRP PG asphalt, pre-blended polymer-modified asphalt and
SBR latex polymer modified asphalt has led many contractors to use SBR
latex for modifying their hot mix asphalt for warranty work in order to
reduce rutting, raveling and cracking and minimize their future maintenance