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(dull resonant music)

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(logo whooshes)

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- [Narrator] A key to creating
longer lasting roadways

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is preventing issues due to
asphalt rutting and cracking.

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And having simulations that closely mimic

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real world conditions

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is key to understanding how
asphalt will ultimately perform.

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The Texas Department of Transportation,

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working with the University
of Texas at El Paso

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and the Center for
Transportation Research,

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investigated current laboratory practices

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to determine methods that best imitate

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different aging states

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to help design an asphalt mixture

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that is more resistant
to rutting and cracking.

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- The project that we are focusing on

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has to deal with the aging of
the hot mix asphalt pavement

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after it's been laid down.

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- We can design material on day one,

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but we don't know how
environmental effects

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negatively impact it over time.

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- [Soheil] As we lay down the asphalt

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and as the sun hits it day in and day out,

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the material becomes more brittle.

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One of the goals of this project

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is to simulate that state of brittleness

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in the material in the laboratory

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before we lay down the asphalt

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to make sure that it would last.

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- [Travis] If we can impose
those environmental effects

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in the laboratory today,

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we can design a material
that will last much longer.

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- One of the problem is that it would take

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around five days to a week

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to simulate the system in the laboratory.

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Or on the other hand, if they accelerated,

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they would not achieve the state

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that the pavement has, the
asphalt has in the field.

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- [Travis] And then you start
throwing in multiple projects

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and multiple mixtures,

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you're really gonna tie up a
lot of ovens and a lot of time.

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And so while this seems
to give us good data,

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it doesn't necessarily lend itself

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to being a usable test
all the time, right,

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because it's not very practical.

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- [Soheil] So our mission
was to come up with a way

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of ranking the different mixes
in a short period of time

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so that it can be practical
for the DOTs to use.

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So we looked at two different processes,

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one oxidizing and
generating the brittleness

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through oxidation by using ozone,

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and the second one by using pressure

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with the goal of reducing the time

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from a week, five to days to a week,

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to maybe less than 48 hours.

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- If we can utilize these
different methods and say,

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"Can we design a mixture
on day one that's good?"

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and then see, you know,

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we predicted in two years
it would still be good,

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and let's see if it's still good.

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And so this is going to
be a lengthy process,

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but I do think this is the next step

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in ensuring that we're making
cracking-resistant material.

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- [Soheil] The main benefit

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is that you can achieve the oxidation

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that is representative
of the field condition.

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These are the two important things.

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You can achieve it in a
very short period of time.

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So for every mix, we can
go through this process

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and not delay the construction.

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- [Narrator] For more information,

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and to find the publication
for this project,

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please visit the TxDOT Research Library

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at the link shown below.