Electrically Conductive Concrete - University of Houston

Electrically
Conductive Concrete

Michelle Ho

University of Houston
Cullen College of Engineering

[email protected]

Electrically Conductive Concrete

• Definition

Chopped Carbon Fiber
(CCF)
Resistive heating

Problem

• Ice and snow build-up

driving hazards
traffic and time
delays

History and Past Projects

• Sodium chloride

Pros

Inexpensive
Simple application

Cons

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

• 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
– Reduce damage and maintenance to concrete

and environment

Scope

• Investigation into conductive concrete’s:

– Resistive 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 Sample connected to a power
supply
Two point probe method
Input: voltage
Output: current readings
V=I*R

Slope: resistance

• Heating Testing

– Heating and Cooling
– Temperature and current

readings

Resistivity Results

Average Resistance (Ohms) vs. % CCF by Mass of Cement

Resistance (Ω) 500
450
400 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80
350 % CCF by Mass of Cement
300
250 Zinc Mesh
200
150
100

50
0
0.80

Resistivity Results (cont’d)

Resistance (Ohms) vs. % CCF by Mass of Cement

Resistance (Ω) 500
450
400 0.90 1.00 1.10 1.20 1.30 1.40 1.50 1.60 1.70 1.80
350 % CCF by Mass Cement
300
250 Zinc Mesh
200
150
100

50
0
0.80

Problem

• Due to the unexpected high amount of
resistance encountered when the sample
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

Resistance (Ω) 3000 Cooling 1% CCF
2500 Cooling 1.67% CCF
2000 -5
1500 0 5 10 15 20 25
1000 Temperature (°C)

500
0
-10

Heating Results

Resistance (Ω) 2000 1% CCF Heating
1800 1.67% CCF Heating
1600 -10 -5 0 5
1400 Temperature (°C) 10 15 20
1200
1000

800
600
400
200

0
-15

Example of mortar blocks in a freezer

Discussion

• Resistive Testing

Correlation

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)
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 Fly Ash
to solve resistance problem in
the heating test

• Various course aggregates
and admixtures

• Sonication and compaction

– eliminate entrapped air
bubbles in non-solidified
concrete mixtures

Acknowledgements

• Dr. Mo – REU advisor
• Dr. Gangbing Song – Faculty Mentor
• Christiana Chang – Masters Mentor
• 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/j
pg/site26/20080204/0010dc53fa040910b7cd05.jpg

• http://www.fhwa.dot.gov/PAVEMENT/recycling/fach01.cfm
• http://www.tohotenax.com/tenax/en/products/images/photo_chopped.j

pg
• http://img.directindustry.com/images_di/photo-g/chopped-carbon-

fiber-363314.jpg
• http://www.allwarm.com/images/installdway1.jpeg
• http://www.instablogsimages.com/images/2008/01/01/roadenergysyste

ms_6648.jpg
• http://www.dailycommercialnews.com/images/archivesid/32825/400.j

pg
• 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.”
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.