conductive concrete overlay for bridge deck...
TRANSCRIPT
Conductive Concrete Overlay for
Bridge Deck Deicing
Sherif Yehia, Ph.D., PE
March 2008
Acknowledgment
• Research Team– Christopher Tuan, Ph.D., PEUniversity of Nebraska - Lincoln
– Osama Abudayyeh, Ph.D., PE
– Ikhlas Abdel-Qader, Ph.D., PEWestern Michigan University
– Ammar Zalt, Bridge Engineer, PARSONS
– Vijay Meganathan, Terasoft International Inc., Arlington Heights, IL
Outline
• Background
• What is Conductive Concrete
• Conductive Concrete Mix Design
– Mixing Procedure
– Implementation Projects
• Construction
• Operation
• Modified Mix at Western Michigan University
• Concluding Remarks
• Questions
Background
Existing Deicing Methods
• Deicing Chemicals
• Insulation against Freezing
Background
Heating Systems
Electric Cables in the Bridge Approach
Roadway, Newark, New Jersey 1961
Approximate Cost
$5/ft2
Background
Heating Systems
Deck Heating System on Approaches of a
Pedestrian Overpass in Lincoln, NE, 1993
Approximate Cost
$16/ft2
Background
Heating Systems
Deck Heating System in the Buffalo
River Bridge, Amherst, Virginia, 1996
Approximate Cost
$35/ft2
• What is Conductive
Concrete?
• Conductive Concrete
Applications
Conductive Concrete
Conductive Concrete Mix Design
The Conductive Concrete Mix Contains :
–Carbon & Graphite Products
–Steel Fiber
In addition to cement, fly ash, silica fume,
sand, coarse aggregate, water, and
superplasticizer
Deicing 1998
Deicing 1999
Deicing 2000
Mixing Procedure
(Mass production)
Mixing procedure
(Mass Production)
Mixing procedure
(Mass production)
Implementation Projects
• Test section on I-480 Missouri River
Bridge, 1999
• Implementation Project at Shelby City,
OH, 2001
• Roca Spur Bridge, Roca Nebraska, 2002
Test section on I-480 Missouri River
Bridge using conductive concrete
mix.
Implementation Project
Material evaluation - Durability test (I-480 Patch)
under traffic load and freeze-and-thaw action.
Poured on December 3, 1999
Implementation Project
at
Shelby City, OH
September 2001
Temperature Sensors
Site Before Casting Concrete
Casting
Finishing I
Finishing II
Finishing - Final Touch
Implementation Project - Roca
Spur Bridge
• Roca, located about 15 miles south of Lincoln, Nebraska
• The Roca Spur Bridge is a three-span slab type bridge has a 45.70m (150 ft) long and 11m (36 ft) wide concrete deck
• The Bridge has a 36 m (117 ft) long and 8.5 m (28 ft) wide conductive concrete inlay
• The inlay consists of 52 individual 1.2m 4.1m (4 ft 14 ft) conductive concrete slabs
Working with Ready Mix Concrete – Lincoln, NE
Mixing Procedure
• The conductive concrete mix with steel fibers
and carbon and graphite products was used
to cast the inlay
• Several, two cubic yards, trial batches were
prepared to examine the mixing procedure
and travel time from the mixing plant to the
job site
• The contractor and the pouring and finishing
crews practiced at a test site
March 21, 2006
Feb 13, 2007
Temperature Time History - Dec. 17, 2003
0.0
5.0
10.0
15.0
20.0
25.0
30.0
35.0
40.0
45.0
50.0
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00
Time (hrs)
Tem
p.
(F)
Slab 1 Slab 2
Slab 3 Slab 4
Slab 5 Slab 6
Slab 7 Slab 8
Slab 9 Slab 10
Slab 11 Slab 12
Slab 13 Slab 14
Slab 15 Slab 16
Slab 17 Slab 18
Slab 19 Slab 20
Slab 21 Slab 22
Slab 23 Slab 24
Slab 25 Slab 26
Slab 27 Slab 28
Slab 29 Slab 32
Slab 33 Slab 34
Slab 35 Slab 36
Slab 37 Slab 38
Slab 39 Slab 40
Slab 41 Slab 42
Slab 43 Slab 44
Slab 45 Slab 46
Slab 47 Slab 48
Slab 49 Slab 50
Slab 51 Slab 52
Ambient
1
2
3
4
5
6
7
-25 -15 -5 5 15 25
Temperature (oC)
Ele
ctr
ica
l c
urr
en
t (A
mp
s.)
1/25/2004
2/1/2004
2/5/2004
1/6/2005
2/8/2005
2/17/2006
3/18/2006
1/13/2007
1/19/2007
2/13/2007
Stability of Electrical Conductivity
Modified Conductive Concrete
Mix Developed at WMU
• The main objective of this research project
is to make the conductive concrete an
economical viable deicing method. This
can be achieved by the following:
– Reduction of the operating voltage and
current requirements.
– Development of a simplified mix procedure
Conductive Concrete Mix
Developed at WMU
• Optimization and mix proportioning
• Evaluation of the mechanical properties
of the optimized mix
• Investigation of an electric model for the
optimized mix
Temp Vs Time
0
10
20
30
40
50
60
70
80
0 5 10 15 20 25 30 35 40 45
Time in Min
Te
mp
in F
Slab 1
Slab 2
Slab 3
Slab 4
Slab 5
Slab 6
Salb 7
Comparison of all Slabs Temperature readings
Temp vs Time
0
10
20
30
40
50
60
0 5 10 15 20 25 30 35 40 45
Time in Minutes
Tem
p in
F
Slab #4(80 volts)
Slab #5(80 Volts)
Slab #6 (80 volts)
Slab #4(60 volts)
Slab # 5(60 volts)
Slab #5 (100 volts)
Slab #6(100 volts)
Slab #4( 100 volts)
Temperature vs. Time Using Different
Voltage Values
Concluding Remarks
• The conductive concrete deicing technology can
be readily implemented at accident-prone areas
such as bridge overpasses, exit ramps, airport
runways, street intersections, sidewalks, and
driveways
• The heated bridge deck of Roca Spur Bridge is
the first implementation in the world of using
conductive concrete for highway bridge deicing
Concluding Remarks
• The initial results showed that the modified
conductive concrete mix which was
developed at Western Michigan University
has the potential to be used for bridge
deck deicing application as well as the
proposed new applications including
Electromagnetic Shielding and Cathodic
protection of reinforcement.
Questions