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3/27/2008
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Conductive Concrete Overlay for Conductive Concrete Overlay for Bridge Deck DeicingBridge Deck Deicing
Sherif Yehia Ph D PESherif 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 DesignConductive Concrete Mix Design–– Mixing ProcedureMixing ProcedureMixing ProcedureMixing Procedure–– Implementation Projects
•• ConstructionConstruction•• OperationOperation
• Modified Mix at Western Michigan University
•• Concluding RemarksConcluding Remarks
•• Questions Questions
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BackgroundExisting Deicing Methods
• Deicing Chemicals• Insulation against Freezing
BackgroundHeating Systems
Electric Cables in the Bridge Approach Roadway, Newark, New Jersey 1961
Approximate Cost$5/ft2
BackgroundHeating Systems
Deck Heating System on Approaches of a Pedestrian Overpass in Lincoln, NE, 1993
Approximate Cost$16/ft2
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BackgroundHeating Systems
Deck Heating System in the Buffalo River Bridge, Amherst, Virginia, 1996
Approximate Cost$35/ft2
• What is Conductive
Concrete?
Conductive Concrete
• Conductive Concrete
Applications
Conductive Concrete Mix DesignConductive Concrete Mix Design
The Conductive Concrete Mix Contains :The Conductive Concrete Mix Contains :–– Carbon & Graphite ProductsCarbon & Graphite Products–– Steel FiberSteel FiberIn addition to cement, fly ash, silica fume, In addition to cement, fly ash, silica fume,
sand, coarse aggregate, water, and sand, coarse aggregate, water, and superplasticizer superplasticizer
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Deicing 1998
Deicing 1999
Deicing 2000
Mixing Procedure(Mass production)
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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
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Implementation Project
Material evaluation - Durability test (I-480 Patch)under traffic load and freeze-and-thaw action. Poured on December 3, 1999
Test section on I-480 Missouri River Bridge using conductive concrete mix.
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Implementation Project
at
Shelby City OHShelby City, OH
September 2001
Temperature Sensors
Site Before Casting Concrete
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Casting
Finishing I
Finishing II
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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 slabThe 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
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Working with Ready Mix Concrete – Lincoln, NEMixing Procedure
• The conductive concrete mix with steel fibers and carbon and graphite products was used to cast the inlayS l t bi d t i l b t h• 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
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March 21, 2006
Feb 13, 2007
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25.0
30.0
35.0
40.0
45.0
50.0
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
Temperature Time History - Dec. 17, 2003
0.0
5.0
10.0
15.0
20.0
0.00 2.00 4.00 6.00 8.00 10.00 12.00 14.00
Time (hrs)
T
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
4
5
6
7
rren
t (A
mps
.) 1/25/20042/1/20042/5/20041/6/20052/8/2005
Stability of Electrical Conductivity
1
2
3
4
-25 -15 -5 5 15 25
Temperature (oC)
Elec
tric
al c
u 2/17/20063/18/20061/13/20071/19/20072/13/2007
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:can be achieved by the following:– Reduction of the operating voltage and
current requirements.– Development of a simplified mix procedure
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Conductive Concrete Mix Conductive Concrete Mix Developed at WMUDeveloped at WMU
• Optimization and mix proportioning• Evaluation of the mechanical properties p p
of the optimized mix• Investigation of an electric model for the
optimized mix
Temp Vs Time
50
60
70
80
n F
Slab 1
Slab 2
Slab 3
Comparison of all Slabs Temperature readings
0
10
20
30
40
0 5 10 15 20 25 30 35 40 45Time in Min
Tem
p in Slab 4
Slab 5
Slab 6
Salb 7
Temp vs Time
40
50
60
Slab #4(80 volts)
Slab #5(80 Volts)
Temperature vs. Time Using Different Voltage Values
0
10
20
30
40
0 5 10 15 20 25 30 35 40 45
Time in Minutes
Tem
p in
F
Slab #6 (80 volts)
Slab #4(60 volts)
Slab # 5(60 volts)
Slab #5 (100 volts)
Slab #6(100 volts)
Slab #4( 100 volts)
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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 bridgehas 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
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