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(gentle music)

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- [Narrator] Innovative construction

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and maintenance practices are
an important part of repairing

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and preserving our nation's bridges.

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The Texas Department of Transportation

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with help from the
University of Texas Center

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for Transportation
Research is implementing

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more accurate estimates of sheer capacity

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of post-tensioned spliced girders,

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a cost effective and durable technology

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for bridges of intermediate to long span.

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These improved estimates
cover both the cases

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where the ducts are not filled with grout

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at the construction stage

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as well as the final stage after grouting.

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In addition, the implementation provides

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full design equations for both
cases that will be adopted

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in national practice, an
area of Texas leadership.

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- Commonly pre-stressed concrete
bridges have a limitation

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of about 150 or 160 foot span length,

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and that is defined by the
limitations that we have

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in transporting these precast girders.

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- TxDOT over the last few years
has been advancing the use

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of what are called precast
prestress and post-tensioned

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splice girder bridges
that use precast concrete.

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These structures enable what is usually

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the lowest cost bridge
super structure material

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to span longer than their typical precast

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pre-stressed beam cases.

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- [Oguzhan] We're giving
the concrete industry

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a chance to compete with
the steel industry to bid on

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longer span bridges to
where the taxpayers can have

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the benefit from the competing bids

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to reduce the bridge cost step.

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- [Michael] These beams typically
have a longitudinal hole,

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if you will that is cast into the girders

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and it's used either a
plastic or metal duct

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which is typically about
four inches in diameter.

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- [Oguzhan] And running
high strength steel strands

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through those ducts and stressing those.