Pavement Preservation Journal - Summer 2015 - (Page 45)
Report: Enhancer Provides
Antistrip Performance in
With respect to long-term pavement preservation, the
one characteristic that destroys pavements is moisture.
Once moisture enters between the bitumen and the stone,
failures start to occur.
Most agencies use either AASHTO T283 (TSR) or
AASHTO T324 (Hamburg) specs. Unless a technician does
extended time and temperature testing for comparative
purposes, he will not recognize that ZycoTherm
nanotechnology provides for a pure chemical bond versus
physical bond, precluding moisture from interfering
between the bitumen and aggregate.
ZycoTherm's chemical bonding performance enhancer is
the only one like it today in the marketplace, the maker says.
The combined enhancer and bitumen chemically bonds to
the aggregate structure, as opposed to conventional products,
typically amines, which only provide a physical bond.
The maker likens this performance to an orange and an
apple. The orange reflects conventional antistrips as the
rind can peeled off easily with a thumb, as opposed to an
apple, which requires a knife to remove. Physical bonding
is only a bandage to the skin, and users might expect
similar results in the field, Zydex Industries says.
By comparison to all the other technologies, ZycoTherm
provides the chemical bond necessary for long term
performance and preservation, the firm maintains.
Comparative analyses from the lab to field projects has
demonstrated the influence of ZycoTherm to both the
manufacturing process as well as the placement of the
asphalt mix, the maker says. In many cases, the mix designs
also have added a combination of RAP (up to 40 percent)
and RAS (up to 5 percent) with favorable results.
Edited from material submitted by Zydex Industries
bonding to aggregates
not physically (left),
with other benefits
to mixes as well,
IMAGE CREDIT: ZyDEx INDusTRIEs
or many years and for many reasons, road
agencies in both the United States and Canada
have been increasing the use of warm mix asphalt
Recently the many HMA producers have chosen the
foaming method to make WMA, as in most cases that will
meet the minimum state specification requirements. In
doing so they also have included additives for antistrip
As the season gets later in the year and working
conditions get colder, or if the hauls from the plant to
the site are quite long, loss of heat in a mix causes many
contractors to add a WMA additive as a compaction aid to
meet minimum state requirements with cooled mixes.
In Europe the specifications simply are based on
performance requirements, and the vast majority of the
major contractors over the last two years have chosen a
product called ZycoTherm as a nanotech-based antistrip
which provides a chemical instead of physical bond, yet also
providing warm mix performance and better coating and
wetting, allowing for greater flexibility and workability, the
A lab protocol developed by Zydex Industries supports
these attributes, the maker says. The lab protocol closely
simulates plant and field conditions, which provides a new
method of determining optimum dosage for antistrip, and
then adds only 0.05 percent for the WMA benefits needed.
In the lab, the addition of ZycoTherm was carried out
on the basis of the instructions for "mixing report with
asphalt binding agent/mixing report for asphalt mixtures"
provided by the customer. A special mixer with a Cowles
agitator for producing emulsions was used for this
The ZycoTherm additive was mixed with the bitumen
heated up to 160 deg C (320 deg F) for at least 10 minutes.
The resulting bitumen then was added to the preheated
stone in the mixer and the mixing process was started.
Using the Cowles agitator and mixer provides for
high shear blending, which simulates plant and field
conditions. This is extremely important as high shear is
required to sufficiently disperse this material into the
Contractors using ZycoTherm have noted a faster wetting
and coating cycle, which has enabled them to complete
projects more efficiently.
pavement preservation journal
Table of Contents for the Digital Edition of Pavement Preservation Journal - Summer 2015
Pavement Preservation World Convenes at PPRS Paris 2015
PPRS Paris: ARRA, AEMA and ISSA Meet at Same Venue
Superior Program Earns FP2 Award for Charleston County
Focus on Preservation at NCAT Pavement Test Track Meeting
Preservation Paramount at Record World of Asphalt
Under Traffic, Rejuvenating Fog Seal Preserves I-475
New Cold Milling Rules will Reduce Respirable Silica
Revised Recycling Manual Now Available from ARRA
San Diego County Preservation Work Wins ISSA’s Top Award
Report: Enhancer Provides Antistrip Performance in Adverse Conditions
Index of Advertisers
Pavement Preservation Journal - Summer 2015