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(gentle music)

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- [Narrator] Closure joints
are essential in the technique

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of accelerated bridge
construction or ABCs.

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These structures require
materials that cure

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and gain strength quickly

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while maintaining long-term durability.

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The Texas Department of Transportation

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and the Center for Transportation Research

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develop high performance mix designs

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with a focus on strength

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and durable closure joints
that will speed up the time

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a structure can begin receiving traffic.

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- The way that Texas has been moving

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is we want construction done faster

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and road closures shortened

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to reduce the impact on
the traveling public.

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- This research was driven by the need

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to be able to reconstruct bridges,

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especially in highly congested areas

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and what's called accelerated
bridge construction

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or ABC projects.

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And the whole goal and the big picture

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is to be able to essentially
come in over a weekend

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and replace a bridge

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by casting most of the
bridge itself offsite,

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and then have it delivered
over the weekend,

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right after the demolition
of the superstructure,

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erect the entire bridge.

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And the goal would be to open

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that bridge back on Monday
morning, for instance.

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- [Narrator] Creating the bridge off side

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and bringing those pieces on

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during construction can
help speed up the process,

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by having the bridge
partially built beforehand,

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construction time is reduced greatly.

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- [Speaker] And then
our focus was primarily

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just the closure pores,

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which are basically
six inch width sections

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of fiber reinforced concrete

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to essentially stitch the bridge together.

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- The most important finding
from this research project

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has been the mixture type

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requested of what is called UHPC,

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which is ultra high performance concrete.

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And this type of concrete
will cure faster,

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cure stronger than typical concrete.

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- Most important thing we found

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is that the technology is viable.

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We were able to demonstrate
that in the lab,

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but more importantly, we
demonstrated it by tracking

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and monitoring two different bridges

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that TxDOT was in the process

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of designing and constructing,

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and our team was involved
in instrumentation,

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monitoring of those bridges

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over the course of a couple of years.

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- [Speaker] By monitoring
bridges during use

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by normal traffic loading,
we're able to see the stresses

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and forces that go into these joints

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and allow us to see how
these joints are performing,

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whether they're getting over
stress and cracking too much

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or if they're performing
well during the stress

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of normal traffic.

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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.