2019 Gumbo final - Book - Page 66
Long Live the
Asphalt
Engineering Professor Finds a Way to
Increase the Longevity of Our Roads.
niversity mechanical engineering professor Guoqiang
Li and his team worked for the past eight years to
create an asphalt sealant that prevents water from
seeping into the asphalt, increasing its longevity.
The earth’s soft soil with its lack of support is one of the reasons
why streets crack. The other reason is precipitation, which is what
Li’s research is trying to solve. His sealant stops the water from
penetrating into the pavement because when water penetrates it,
cracks become unsealable.
Li majored in civil engineering and taught nine years in pavement
and design, but now teaches mechanical engineering.
“We have already sent humans to the moon, but we just cannot
solve the problem under our feet,” Li said.
The problem is that the pavement suffers from its thermal
properties, Li said. In summer, all the materials expand, but in
the winter all the materials contract. When trying to seal cracks
in pavement, a material that behaves in the opposite way is
necessary. In the summer, the sealant would need to shrink, and in
the winter, it would need to expand.
About 10 years ago, Li started studying shape-memory polymers.
Shape-memory polymers behave opposite to conventional physics
and, with that, realized that shape-memory polymers were a good
material to solve the problem with pavement.
He received grants from the Transportation Research Board and
Louisiana Research Board to study shape-memory polymers. On
what is now Engineering Lane at the University, he installed two
pieces of sealant in 2011. Today, they are still working perfectly,
according to Li.
The materials needed a complex process of agitation. The material
itself does not work opposite to conventional physics, so, as a
result, humans need to agitate it before the installation. This sort of
agitation is a form of mechanical deformation. Two postdoctorates
on his team in 2011 spent their entire winter break trying to prepare
the two pieces of material. Li found this process too complex.
In 2012 and 2013, Li discovered a new material called a two-way
memory shape polymer. This material does not need humans
to agitate it while the regular polymers had to be. Naturally, it
provides the agitation. He disclosed this idea to the University’s
intellectual property office and submitted the first patent
application in 2014, with a second application following in 2018.
The intellectual property office at the University encouraged him
to start a small business in 2016. Hosted in the Louisiana Business
and Technology Center, the Louisiana Multi-functional Material
Group helps develop two-way memory shape polymers. In 2016, Li
received his first Small Business Research Initiative grant from the
National Science Foundation, and last year, he received his second
one, which they are currently working on.
In December, Texas Transportation Institute tested the sealant
in a way that simulated real use, and the material passed their
specification. During the spring, the Louisiana Research Center
will test the pavement in an accelerated loading facility. Pavement
usually takes 20 years to test but, there, it takes three months.
They have also been offered the opportunity to test the sealant
in Minnesota, which offers a cold alternative to the hot and humid
climate of Louisiana.
Story // Sophie Liberto
Photo // Reveille Photographer
Design // Rachel Hurt
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