(dramatic music)
- [Narrator] Ultra high performance concrete
or UHPC presents the potential
of major improvements in bridge construction.
International experiences with UHPC have shown
that a bridge's superstructure weight can be reduced
by as much as 40%.
These weight reductions could represent major design
and construction benefits,
especially for long span bridges.
The Texas Department of Transportation
and the Texas A&M Transportation Institute are looking
into ways UHPC can be used to develop new bridges
in the state.
- This research project was looking
at ultra high performance concrete,
otherwise known as UHPC, and looking
at ways that we can leverage this new material
in terms of use, and our bridge structures.
Specifically looking at girders
and how we can optimize our girders
within Texas infrastructure.
- UHPC includes steel fibers that are very small,
tiny fibers and there are many different types
of fibers out there.
- So it was a mixture of working
with our fabricators and then also working in the lab.
And that's what Mary Beth and her team did
is they actually tested the girders, full-scale testing.
- We used the laboratory facilities
at the Texas A&M University Center
for Infrastructure Renewal.
So we had the opportunity to use
both the materials testing facilities,
as well as the high bay structural testing facility.
And then eventually, we adopted one of those mixtures
for use at a precast plant where we scaled it up
to production and went ahead and did a trial batch.
And when that was found to work well,
we were able to then begin casting bridge girder specimens
that we are then able to test
at full scale to determine the structural performance
of girders using UHPC.
- We want to extend the life of these bridges
and we also want to have projects
that we can deliver quickly.
So we're looking
at a non-proprietary mix that is also cost effective.
- If we look at the expected service life of components made
with this material, we're looking at over 150 years.
And so with that, the challenge is to bring the rest
of the structure up to that same level of service life
and that would allow us to replace bridges less often.
- Within Texas, we do have varying climates
and the environments.
So like let's say in the Panhandle,
and Amarillo, Lubbock, you have freeze thaw,
you have salts that we apply on the roadways
for the public to be able to travel
when it's icy or snowy,
so that actually causes corrosion
that can reduce the lifespan of a bridge.
So because UHPC's more dense,
utilizing fiber in the mix, it has less porosity,
then hopefully we can create more of a watertight seal.
- We were able to test UHPC girders at full scale
and I think the study will definitely help to contribute
to the understanding and the confidence
in using this material in bridge girders.
One of the things that we were able to do
is to actually test the girders with the cast-in-place deck
on top, which represents better what we find in the field.
And so from that point of view,
we can provide a more realistic understanding
of the performance of these bridge girders in practice.
- [Narrator] For more information
and to find the publication
for this project, please visit the TxDOT Research Library
at the link shown below.