Electrically
Conductive Concrete
Michelle HoUniversity of Houston
Cullen College of Engineering
Electrically Conductive Concrete
• Definition
Chopped Carbon Fiber
(CCF)
Resistive heatingResistive heating
Problem
• Ice and snow build-up
driving hazards
traffic and time traffic and time
delays
History and Past Projects
• Sodium chloride
Pros Inexpensive
Simple application
ConsCons Ruins groundwater and
vegetation
Corrosion of reinforcing bars
Concrete surface damage
History and Past Projects (cont’d)
• Heating cables Pros
Effective deicing
Cons Traffic disturbances
High energy costs High energy costs
• Heating Pipes Pros
Effective deicing
Cons Leaks lead to almost
impossible maintenance
Complex and costly
Purpose
– Solving the de-icing problem
– Achieving and maintaining cost efficiency– Achieving and maintaining cost efficiency
– Reduce damage and maintenance to concrete
and environment
Scope
• Investigation into conductive concrete’s:
– Resistive properties
– Heating properties– Heating properties
Design of System
Design of System (cont’d)
• Two types of electrodes
– Zinc Perforated Metal Sheets (a)
– Aluminum Mesh (b)
(a) (b)
Procedures
• Resistivity Testing
Two point probe method
Input: voltage
Output: current readings
V = I * R
Slope: resistance
• Heating Testing
– Heating and Cooling
– Temperature and current
readingsSample connected to a power
supply
Resistivity ResultsAverage Resistance (Ohms) vs. % CCF by Mass of Cement
250
300
350
400
450
500
Re
sis
tan
ce
(Ω
)
0
50
100
150
200
250
0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80
% CCF by Mass of Cement
Re
sis
tan
ce
(
Zinc Mesh
Resistance (Ohms) vs. % CCF by Mass of Cement
300
350
400
450
500
Resis
tan
ce (Ω
)Resistivity Results (cont’d)
0
50
100
150
200
250
0.80 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80
% CCF by Mass Cement
Resis
tan
ce (
Zinc Mesh
Problem
• Due to the unexpected high amount of
resistance encountered when the sample
was frozen, which did not occur when the was frozen, which did not occur when the
sample was at room temperature, a heating
and cooling test were done to investigate
the relationship between temperature and
resistance.
Cooling Results
2000
2500
3000
Re
sis
tan
ce
(Ω
)
Cooling 1% CCF
Cooling 1.67% CCF
0
500
1000
1500
-10 -5 0 5 10 15 20 25
Temperature (°C)
Re
sis
tan
ce
(
Heating Results
1200
1400
1600
1800
2000
Re
sis
tan
ce
(Ω
)
1% CCF Heating
1.67% CCF Heating
0
200
400
600
800
1000
-15 -10 -5 0 5 10 15 20
Temperature (°C)
Re
sis
tan
ce
(
Example of mortar blocks in a freezer
Discussion
• Resistive Testing
Correlation
Inversely proportional relationship between Inversely proportional relationship between
resistance and percentage of CCF
Increase in CCF triggers a decrease in resistance and
increase in current
Discussion (cont’d)
• Heating Testing
Problem
Resistance too high (quadrupled)Resistance too high (quadrupled)
Only .05 A and 1 W power output with 20 V input
Correlation: Inversely proportional relationship
between temperature and resistance
Future Work
• Design better concrete system
to solve resistance problem in
the heating test
• Various course aggregates • Various course aggregates
and admixtures
• Sonication and compaction
– eliminate entrapped air
bubbles in non-solidified
concrete mixturesFly Ash
Acknowledgements
• Dr. Mo – REU advisor
• Dr. Gangbing Song – Faculty Mentor
• Christiana Chang – Masters Mentor
• The research study described herein was • The research study described herein was sponsored by the National Science Foundation under the Award No. EEC-0649163. The opinions expressed in this study are those of the authors and do not necessarily reflect the views of the sponsor.
References
• http://www.newsgd.com/news/picstories/content/images/attachement/jpg/site26/20080204/0010dc53fa040910b7cd05.jpg
• http://www.fhwa.dot.gov/PAVEMENT/recycling/fach01.cfm
• http://www.tohotenax.com/tenax/en/products/images/photo_chopped.jpg
• http://img.directindustry.com/images_di/photo-g/chopped-carbon-fiber-363314.jpgfiber-363314.jpg
• http://www.allwarm.com/images/installdway1.jpeg
• http://www.instablogsimages.com/images/2008/01/01/roadenergysystems_6648.jpg
• http://www.dailycommercialnews.com/images/archivesid/32825/400.jpg
• Christiana Chang (2009). “Development of Self-Heating Concrete Utilizing Carbon Nanofiber Heating Elements.”
References (Cont’d)
• Cress, M. D. 1995. “Heated bridge deck construction and operation in Lincoln, Nebraska.” IABSE Symp., San Francisco, 449–454.
• Roosevelt, D. S. 2004. “A bridge deck anti-icing system in Virginia: Lessons learned from a pilot study,” Final Rep. No. VTRC 04-R26, Virginia Transportation Research Council, Charlottesville, Va.
• Sun Mingquing, Li Zhuoqiu, and Mao Quizhao. 1997. “Study on the Electrothermal Property of CFRC[J].” Journal of Wuhan University of Technology. V 19. Issue 2. 72-74.
• Tang, Zuquan. June 2006. “Influential Factors on Deicing Performance of electrically Conductive Concrete Pavement.” Journal of Wuhan University of Technology – Mater. Sci. Ed. Volume 21. No 2.
• Tang, Zuquan, Li Zhouqiu, Hou Zuofu, et al. 2002. “Influence of Setting of Electrical Conductive concrete Heating Layer on Effectiveness of Deicing[J].” Journal fo Wuhan University of Technology – Mater. Sci. Ed. Volume 17. Issue 3. 41-45.
• Tuan Christopher Y. March 2008. “Roca Spur Bridge: The Implementation of an Innovative Deicing Technology.” • Tuan Christopher Y. March 2008. “Roca Spur Bridge: The Implementation of an Innovative Deicing Technology.” Journal of Cold Regions Engineering (U. of Nebraska). Volume 22 Issue 1, 1-15.
• Tuan, Christopher Y. 2004. “Electrical Resistance Heating of Conductive concrete Containing Steel Fibers and Shavings.” ACI Materials Journal, V. 101, No. 1. 65-71.
• Williams, D., Williams, N., and Cao, Y. (2000). “Road salt contamination of ground water in major metropolitan area and development of a biological index to monitor its impact.” Water Research, 1 (34), 127-138.
• Yehia, Sherif and Tuan, Christopher Y. 1998. “Bridge Deck Deicing.” Transportation Conference Proceedings, Department of Civil Engineering, University of Neraska-Lincoln. 51-57.
• Yehia, S. A., Tuan, C, Y., Ferdon, D., and Chen B. 2000. “Conductive Concret Overlay for Bridge Deck Deicing: Mixture Proportioning Optimization, and Properties.” ACI Materials Journal. V. 97, No. 2. 172-181.