Florida’s Contribution to Prestressed Concrete

INTRODUCTION
Florida’s Contribution
to Prestressed Concrete
Earliest History
“ Practical end of the Beginnings is 1958”
Professor Magnel’s efforts
William Dean and the start in 1948
National Standards and Fl State Road
Department Specs
Since the 60’s
Continuing Modernization of Prestressed Systems
Earliest History in the United States
Cement Invented in 1800’s
Prestressed Concrete Lintels in
1896 in San Francisco by
Henry Jackson….. Deflected
and cracked after two years
Ben Gerwick tried to make
beams using wire rope in 1910
but loosely stranded rope
unwound.
In the 1920’s Technology transfer
Herbert Hoover started the
“Commission for Relief in Belguim”
program… Hoover later became the
31st President.
Beginning in 1920 graduate students in
law, medicine, engineering, etc. were
brought to the U.S. for one year stay.
In the 1940’s in Ghent, Belgium
Professor
Gustave Magnel
(1889-1955)
started his
reinforced
concrete
laboratory in
1926.
The German’s removed Professor
Magnel from University influence in 1940
and limited his activities to the lab
THE 1930’s
Charles Zollmann became a a graduate
student under Professor Gustave Magnel in
Belguim in 1939
The Tour from April to June 1946
Magnel toured the United
States as “Belgian American
Educational Foundation
(BAEF) Scientist”
THE Reunion in 1946
The start with Charles Zollmann and
Professor Gustave Magnel in the States
First Prestressed Concrete Book
6000 copies
1st published in 1948
By Gustave Magnel
2nd Edition in 1950
3rd Edition in 1954
Walnut Lane Test on Oct. 25, 1949
GROUTING FOR INTERIOR SPANS
Field trip in 1954
Walnut Lane Test on Oct. 25, 1949
Sunshine Skyway Bridge
The original 1946 bids
exceeded the budget.
Meeting in April 1950
with Charles Zollmann
and Ed Thwaits of
Preload Corp. with
Bill Dean…..
Bill Dean’s comment,
“I have gone sour on
prestressed concrete”
Sorry you feel that
way… would you like to
see some photographs
of Walnut Lane?
Sunshine Skyway Bridge
In 1951 Bids were taken
for the full scale testing
and construction of 363
trestle spans of 48’ with
precast prestressed
concrete girders. Saving
1 pier every 144’ over
the original 36’
reinforced concrete
design.
At this time (1951) it was
the largest contract for
prestressed members
ever let in any part of
the world.
The Nation in March 1952
“Communism Prohibits free enterprise…..”
Army Corp of Engineers in the 1950’s
Korea in 1953
Florida in the 1950’s
Professor T.Y. Lin
returned from
Ghent, Belgium in
1954 and began
writing his text
book.
Until 1955, when T.Y. Lin published his book on Design
of Prestressed Concrete Structures, Magnel’s book was
the only English text on the subject.
October 10-12, 1955
PCI’s First
National
Prestressed
Concrete Short
Course,
presented in St.
Petersburg, Fl.
Charles Zollmann
Bill Dean
Bill Dean’s paper titled “Outlook To The Future Of
Prestressed Concrete”
1979 PCI Journal states: “Written 23 years ago, many of
the concepts Dean talked about are still relevant today.”
Bill Dean credits:
Dean’s efforts continued …..
UF under Dean’s direction “proved beyond any shadow
of doubt that end blocks in pretensioned bridge beams
were superfluous.”
Dean pushed a head for larger strands… inspite of the
objections of the Bureau of Public Roads
Dean fought to remove keys… Dean tested girders and
concluded “If sufficient steel is provided to develop the
vertical compression..” After a intensive testing program
in 1957 Florida “extended stirrups to develop the…
shear keys were generally eliminated. Before long the
practice was followed nationwide--- with no comeback
from Bureau of Public Roads
Bill Dean quotes:
Dean’s efforts continued …..
The general air of most attendants was one of intense interest
with a generous portion of skepticism.
As Chairman of the Joint AASHO-PCI Committee Dean
fought for the “fat and sassy” standards, not the slender
European counterparts…. This upset BPR.
“Prestressed Concrete is an engineered material….All of the
principals of mechanics of materials still apply and the law of
gravity has not been repealed simply because we have become
adept at overcoming an inherent weakness of concrete.”
Dean wrote, “Thanks so much for your congratulatory letter.
These newspapers have to fill up space somehow and I was
just odd-ball enough to qualify. The color photo can be
obtained thru the Sentinel Star Photo Office but it sure as Hell
ain’t worth the price.”
Dean’s efforts continued …..
William Ennes Dean (1909-1965)
Dean’s efforts continued …..
He worked at SRD from 1932 to 1963.
He was promoted to State bridge engineer at the age of 40.
After Bill Dean’s
retirement in 1962
from SRD he joined a
consulting firm where
he designed the
Spliced girders at
Sebastian inlet in
1963. Bill Dean died
from a fatal heart
attack on December
30, 1965 while
inspecting the
Hathaway Bridge in
Panama City, Fl.
Florida in the 1950’s
POURBACK TREATMENT AT EXPANSION
JOINTS (ABUTMENT SIMILAR)
Florida in the 1950’s
PCI legally chartered June 18, 1954, in Tampa, Fl.
1st Convention April 21-22, 1955 in Ft. Lauderdale
2nd Convention May 16-18, 1956 in Hollywood, Fl.
Florida in the 1950’s
Florida in the 1950’s
REPAIR OF DECK ACCESS
HOLES
1954 Specification Development
LEVELS OF PROTECTION (CONT)
1954 Specification Development
1957 AASHO BRIDGE CODE
1961 AASHO BRIDGE CODE
1961 AASHO BRIDGE CODE
Note:
Page 126 thru 134
54\57 FL SRD Construction Spec.
Florida in the 1950’s
The intial PCI Journal
was published in May
1956 under the editorship
of Professor Dr. Alan M.
Ozell of the University of
Florida.
Harry Edwards wrote UF Professors
Kluge, Ozell, Sawyer, and Zia
performed considerable research
during the 50’s and 60’s which
resulted in extremely valuable
contributions. The research was
funded by SRD, Producers, PCI and
the University.
Florida in the 1950’ and 60s
Harry Edwards, founder of
Leap Associates in 1950
concentrated its services
almost exclusively to the
engineering of pretensioned
products. His firm developed
the double tee cross section.
He served as the first
Secretary-Treasure of PCI
from 1954 to 1956.
During the 50’ and 60’ Harry
sponsored many 3 day
workshops to advance the
understanding of Prestressed
products.
Florida in the 1950’ and 60s
During the 1950’s most strand was produced
by the John A. Roebling’s Sons Corp., the
company which pioneered strand
development.
In 1958, Edward Danciger founded Florida
Wire and Cable and began production of
strand in 1960.
In 1974 Colorado Fuel and Iron (purchased
Roebling) ceased strand production.
Sunshine Skyway Bridge
Florida in the 1970’s
)
Sunshine Skyway Bridge
Florida in the 1970’s
Florida in the 1970’s
In 1973, Bollmann wrote, “That the damaged girders
tested still met the AASHO HS-20 loading”
Florida in the 1970’s
Florida in the 1979
This was the first continuous segmented girder bridge in FL.
Florida in the 1980’s
Segmental Keys Bridges
New Skyway
Florida in the 1980’s
New Skyway
Florida in the 1980’s
Florida in the 1980’s
Eau Gallie Beam Test
Service level test conducted on June 11, 1985
Ultimate Load test on December 5, 1985
Florida in the 1980’s
Eau Gallie Beam Tests
Florida in the 1980’s
Whom do you recognize?
Florida in the 1980’s
Whom do you recognize?
Florida in the 1980’s
Whom do you recognize?
Florida in the 1980’s
Whom do you recognize?
Florida in the 1980’s
Whom do you recognize?
Florida in the 1980’s
Whom do you recognize?
Constructed between 1985 and 1993
12 structures with 2
staged PT system
17 Bulb Tee Structures
QUESTIONS / ANSWERS
Florida in the 1980’s
Florida in the 1980’ and 90’s
Prestressed Girder Repairs
Florida in the 1980’ and 90’s
Bridge Testing
Florida in 1999
All because of 8500 PSI
2000 PT Durability
FDOT Post-Tensioning Strategy
Enhanced PT Systems
Fully Grouted Tendons
Multiple Tendons Paths
FDOT PT
Strategy
Watertight Bridges
Anchor Protection
2000 PT Durability
Post-Tensioning Tendon
Classification Criteria
• Type of Construction
• Tendon Protection System
CIP on Falsework
CIP Balanced Cantilever
P/C Balanced Cantilever
P/C Span-By-Span
Splice Girders
Continuous P/S Girders
Materials – Duct, Anchor, Grout
Wet vs. Dry Joints
Risk of Exposure
Deck Pockets
Cracked pour backs
• Structural Purpose
• Maintainability
Access to inspect components
& Criticality
Superstructure
Substructure
Bonded vs. Unbonded
# & Distribution of Tendons
Replaceable vs. Non-replaceable
Applicability of test methods
2000 PT Durability
Prestressed Concrete and Florida
References/Acknowledgements
1. PCI JOURNAL “Reflections on the Beginings of
Prestressed Concrete in America”, many authors
included in the 9 part series, Dated 1981.
2. John Dick’s guidance and advice.
3. Florida DOT Historic Highway Bridges.
4. Henry Bollmann’s historic files.
5. PCI JOURNEL “Florida’s Long Span Bridges:
New Forms, New Horizons” by Antonio Garcia
dated July-August 1993.
6. Randy Bradley, Mike Robertson, and Buddy Dekle
for there research and support work.
Prestressed Concrete and Florida
QUESTIONS / ANSWERS