As part of the keynote panel at the 2014 CTR Symposium, Dr. Jirsa discussed 50 years of significant accomplishments at the Ferguson Structural Engineering Laboratory at the University of Texas at Austin.

1. CTR Annual Symposium
50 years of Innovation in Bridge
Design and Construction
April 23, 2014

2. Details, Details, Details
The devil is in the details
or
The beauty is in the details

3. • A large part of the TxDOT Research Program has
been improvement in the detailing of
transportation structures to guide design and
construction
• Hallmarks of the program
–Identification of problem areas from
designers, contractors, or maintenance
personnel
–Large-scale tests
–Implementation of research findings

4. Examples—Concrete Structures
• Development and splices of reinforcement
• Anchor bolt design
• Epoxy-coated bars—performance and quality control
• Dapped ends of beams—strut and tie models
• T-headed bars
• Use of precast panels for bridge decks
– Elimination of thickened ends
– Skewed bridges
• Repair and strengthening of bridge girders
– Damage from over-height loads
– Use of CFRP for strengthening

5. Development and splices of
reinforcement
• 1960’s
– Ferguson began work on development and use of large
bars
• 1970’s and 80’s
– Reevaluation of data
– Tests on wall-type specimens,
– Effects of Casting position, Consolidation and
superplasiticizers, Impact loading, Interaction with shear
• 1990’s
– Bundled bars
– Headed bars

6. Why was this research important?
• Greatly improved understanding of bond
because the tests were large scale
• Provided data that led to major changes in
bridge and building codes
• Findings were incorporated into the TxDOT
Design Manuals
• Gained national and international attention
for TxDOT research program

7. Anchor Bolts
• First work in 1977 resulted in a design equation that was
widely used because there was no other guidance.

8. • In 2007, the behavior of anchor bolts in ASR/DEF
damaged drilled shafts was studied
• Design codes now contain guidance for a large
variety of cases involving anchorages in concrete

9. Bridge Decks
• The use of precast, prestressed concrete (PC)
panels for stay-in-place formwork presented a
difficult construction detail at expansion

10. IBTS I-Beam Thickened Slab Detail

11. Full-scale precast panel (PC) deck
11
Armored joint
Sealed expansion
joint
No skew

12. Full-scale skewed bridge deck
UTSE Uniform
thickness
IBTS
Thickened slab
}

13. Results
• Thickened slab not needed so panels could be
placed at expansion joints
• Formwork at joints no longer needed leading
to a safer work environment
• Expansion joint hardware could be placed in
topping slab
• Punching shear and
flexural capacity of
deck at edge was
much greater than
expected loads

14. Materials
• Epoxy-coated bars for durability
• High-strength concretes and effects of additives
• Fiber and alloy steels in corrosive environments
• Higher strength steels—80 to 100ksi bars are
being studied and will likely be permitted in
codes in the near future
• Materials for life extension--FRP’s, coatings,
chemical treatments

15. Structural Repair and Strengthening
• Similar damage to railroad bridge over Steck Ave. in Austin
• Damaged girder brought to Ferguson Lab for evaluation;
repair of severed tendons; and replacement of damaged
concrete
Damage to Waelder
Bridge over I-10 due to
over-height load
Damage to Waelder Bridge over I-10
due to over-height load

16. Structural Repair and Strengthening
• For increased truck traffic and loadings
• Use of CFRP materials for improving shear
strength of bridge girders
• Combination of CFRP sheets and CFRP anchors
can be used for I and T sections where
complete wrapping is not possible

18. Other topics
• Fatigue studies of steel bridge girders and
illumination poles
• Stability of steel girder superstructures
• Bolted and welded connections
• Behavior of elastomeric bearing pads
• Stability of concrete arches—Fort Worth

19. Impact
• Viewed as leader among states in supporting
research that changed bridge design and
construction practice
• Influenced structural bridge and building
codes worldwide
• Provided training for a cadre of
knowledgeable engineers who became
leaders in the structural engineering
profession

20. Recognition
• Charles S. Whitney Award 1980 from ACI for
noteworthy engineering development work in
concrete design or construction
• Alfred E. Lindau Award 2005 from ACI for
outstanding contributions to reinforced concrete
design practice
• Citations for outstanding individual bridge
projects
• Numerous awards for technical papers based on
TxDOT-sponsored projects

21. Personal Reflections
• TxDOT Research Program
– Cooperation
– Collaboration
– Implementation
• The most rewarding research of my career
• Played a pivotal role in the development of Civil
Engineering at the University of Texas and in the
State of Texas
THANK YOU FOR THESE OPPORTUNITIES