The 2014 CTR Symposium featured a keynote panel of leaders in structural engineering from the Ferguson Structural Engineering Laboratory at the University of Texas at Austin. Featuring innovative work done for TxDOT through the years through CTR, Dr. John Breen discussed significant accomplishments.

1. Post-Tensioning
Developments in Texas
John E. Breen, P.E.
The Nasser I. Al-Rashid Chair in Civil Engineering
Ferguson Structural Engineering Laboratory
The University of Texas

2. Introduction
Segmental box girder bridges
Post-tensioned anchorage zones
Strut-and-tie modeling
Precast post-tensioned substructures
Cable stay and post-tensioned tendon
fatigue criteria
Cable stay and post-tensioned tendon
corrosion protection systems

3. Introduction
40 years of continuous applications
oriented research and development
studies in post-tensioned concrete
Broad sponsorship
– TxDOT – RCRC
– FHWA – NSF
– NCHRP – Industry
– PTI

4. Introduction
Wide Recognition
ASCE Croes Medal, 4 ASCE T.Y. Lin Medals,
Freyssinet Medal, FIP Medal, ASBI Leadership Award,
PCI Outstanding Structure Award, ACI Structural
Engineering Medal
Pages upon pages in AASHTO Standard
Specs, AASHTO LRFD Specs, AASHTO
Segmental Box Girder Guide Spec, ACI
Building Code
Educated dozens of highly qualified
practitioners, researchers, and teachers

5. Segmental Box Girder
Bridges

6. Corpus Christi JFK Causeway
First precast segmental box girder bridge in USA
Model Construction Model Testing

7. Corpus Christi JFK Causeway
First precast segmental box girder bridge in USA

8. Corpus Christi JFK Causeway
First precast segmental box girder bridge in USA
Corpus Christi bridge
under construction
Corpus Christi
bridge completed

9. Segmental Box Girder Bridges
Epoxy Joint Technology
Application Results

10. Segmental Box Girder Bridges
External Tendon Deviators Design
Cage Post-test

11. Segmental Box Girder Bridges
External Tendon Bridges
Span-by-span model Test results

12. Segmental Box Girder Bridges
External Tendon Bridges
183 N - Austin Thermal gradient results

13. Post-Tensioned Anchorage Zones
JFK Causeway Tendon
path cracking
Test specimen

14. Post-Tensioned Anchorage Zones
Local Zone
End Zone
Local Zone
Acceptance Criteria

15. Post-Tensioned Anchorage Zone
Design Criteria
FEA STM

16. Strut and Tie Modeling
3D STM Diaphragm 3D Diaphragm Test

17. Precast Post-tensioned Bridge
Substructures

18. Precast Post-tensioned Bridge
Substructures

19. Fatigue Criteria
Post-tensioning tendon
Specimen Test

20. Fatigue Criteria
External tendon
Test Post-test

21. Fatigue Criteria
Cable stay
Installation Post-test

22. Cable Stay Corrosion
Protection Systems
Grouting of specimen Voids forming

23. Cable Stay Corrosion
Protection Systems
First study that showed concrete grout was not
an effective protective barrier
Grout cracked when
sheath cut
Corrosion at grout
crack

24. Post-tensioning Tendon Corrosion
Protection Systems

25. Post-tensioning Tendon Corrosion
Protection Systems

26. Post-tensioning Tendon Corrosion
Protection Systems

27. Post-tensioning Tendon Corrosion
Protection Systems
Improved grouts
Major contributor to ASBI & PTI improved grouting procedures
Voids

28. Special Thanks
Great students
Dedicated technicians
Cooperative faculty
Patient and visionary sponsors
– Especially TxDOT who never
hesitated to try results in practice