Electrically Conductive Concrete Michelle Ho University of Houston - - PowerPoint PPT Presentation

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Electrically Conductive Concrete Michelle Ho University of Houston - - PowerPoint PPT Presentation

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Electrically Conductive Concrete Michelle Ho University of Houston Cullen College of Engineering smho@uh.edu Electrically Conductive Concrete Definition Chopped Carbon Fiber (CCF) Resistive heating Resistive heating Problem

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SLIDE 1

Electrically Conductive Concrete

Michelle Ho

University of Houston Cullen College of Engineering smho@uh.edu

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SLIDE 2

Electrically Conductive Concrete

  • Definition

Chopped Carbon Fiber (CCF) Resistive heating Resistive heating

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SLIDE 3

Problem

  • Ice and snow build-up

driving hazards traffic and time delays

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SLIDE 4

History and Past Projects

  • Sodium chloride

Pros

Inexpensive Simple application

Cons Cons

Ruins groundwater and vegetation Corrosion of reinforcing bars Concrete surface damage

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SLIDE 5

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

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SLIDE 6

Purpose

– Solving the de-icing problem – Achieving and maintaining cost efficiency – Achieving and maintaining cost efficiency – Reduce damage and maintenance to concrete and environment

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SLIDE 7

Scope

  • Investigation into conductive concrete’s:

– Resistive properties – Heating properties – Heating properties

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SLIDE 8

Design of System

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SLIDE 9

Design of System (cont’d)

  • Two types of electrodes

– Zinc Perforated Metal Sheets (a) – Aluminum Mesh (b)

(a) (b)

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SLIDE 10

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 readings

Sample connected to a power supply

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SLIDE 11

Resistivity Results

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

250 300 350 400 450 500 ance () 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 Resistan

Zinc Mesh
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SLIDE 12

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

300 350 400 450 500 ce ()

Resistivity Results (cont’d)

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 Resistance

Zinc Mesh
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SLIDE 13

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.

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SLIDE 14

Cooling Results

2000 2500 3000 ce ()

Cooling 1% CCF Cooling 1.67% CCF

500 1000 1500

  • 10
  • 5

5 10 15 20 25 Temperature (° C) Resistanc

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SLIDE 15

Heating Results

1200 1400 1600 1800 2000 nce ()

1% CCF Heating 1.67% CCF Heating

200 400 600 800 1000

  • 15
  • 10
  • 5

5 10 15 20 Temperature (° C) Resistan

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SLIDE 16

Example of mortar blocks in a freezer

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SLIDE 17

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

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SLIDE 18

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

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SLIDE 19

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 mixtures

Fly Ash

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SLIDE 20

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.

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SLIDE 21

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 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.”

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SLIDE 22

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
  • f 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.