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Researchers:
Oguzhan Bayrak
James Jirsa
Sharon Wood
Graduate Students:
Lewis Agnew
Clifton Boswell
Alan Kresia
Sponsor: Texas Department of Transportation
(TxDOT), FHWA, DOT
Project Summary
The Texas Department of Transportation (TxDOT) has been a leader in the design of costeffective
prestressed concrete bridges for nearly 50 years. During this time, typical spans have
increased from 50 to more than 100 ft, intermediate and end diaphragms have been eliminated,
and prestressed concrete deck panels have been introduced as stay-in-place formwork for cast-inplace
bridge decks. Each of these improvements has increased the speed of construction,
reduced the cost of bridge construction in Texas, and demonstrated TxDOT’s commitment to
incorporating innovative design concepts into practice. A current concern for TxDOT is the
design and construction of bridge decks at expansion joints. The most common detail used by
TxDOT is the I-beam thickened slab (IBTS) detail, which involves casting a 4-ft wide, 10-in.
deep, heavily-reinforced slab along the expansion joint. This detail increases the transverse
stiffness of the slab near the expansion joint and eliminates the need for diaphragms at the ends
of the spans. However, the detail also complicates the construction process because special
formwork is required at the expansion joints due to the increased thickness of the slab relative to
the interior portions of the deck. The primary objective of this project is to develop precast
solutions to eliminate the need to construct formwork at the expansion joints. The resulting
details will reduce construction time and costs and provide a safer work environment for
contractors.
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