- [Narrator] Making roadways last longer is the goal
of all pavement engineers.
One of the keys to longer life rests in the binders
which are added to pavement mixtures.
Researchers with the Center for Transportation Research
at the University of Texas are developing new test
methods that can help them predict which binders
will resist pavement distress,
specifically rutting, fatigue cracking,
and thermal cracking.
- When you drive on asphalt roads, asphalt binder is quite
literally the glue that's holding these roads together.
It is also the most expensive material
or component material that goes
into production of asphalt mixtures
and therefore the asphalt pavement.
That inherent ability of the binder
to resist cracking is what dictates the serviceable
life of an asphalt pavement.
- There has always been a need for tests or testing
that can accurately detect ability of an asphalt binder to
resist cracking in the field.
This is even more important now as the binder industry
or the binder manufacturers are developing new types
of modifiers and chemicals to improve conditions of asphalt.
- In the original research project
we developed the poker chip test method
and it showed some promise that it was able to detect
whether or not an asphalt binder is susceptible
to premature cracking or not.
In the implementation study, we did two things.
One was, we made the test very practical and easy to use
by any technician in any asphalt laboratory.
And the second thing we did was, we benchmarked the results
from these tests, with the ground truth.
We actually went down to 22 different sections all
across the state, different climatic regions,
traffic volumes, mixture types, pavement types,
and benchmarked the parameters
from this test with the ground truth.
That is, if the test was telling that this pavement
is likely to crack prematurely,
whether or not it was cracking or not.
And we established that connection
between ground reality and what the test was telling us.
- The main use for asphalt is hot mix.
Asphalt mixture and asphalt binder
is the most expensive part.
We use about half a million ton of asphalt binder annually.
We're really looking at any improvement.
Quality of that material will have a really huge impact
on the state in terms of savings, as well as in terms
of having, you know, longer life pavements,
getting more recycled material, as well
as improving the quality of what's practically
the driving cost of our hot mix.
- [Narrator] For more information,
and to find the publications for this project,
please visit the Tex DOT research library
at the link shown below.