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