Piezoresistive response extraction for smart cement-based composites/sensors

Abstract

A kind of piezoresistive response extraction method for smart cement-based composites/ sensors was proposed. Two kinds of typical piezoresistive cement-based composites/sensors were fabricated by respectively adding carbon nanotubes and nickel powders as conductive fillers into cement paste or cement mortar. The variation in measured electrical resistance of such cement-based composites/sensors was explored without loading and under repeated compressive loading and impulsive loading. The experimental results indicate that the measured electrical resistance of piezoresistive cement-based composites/sensors exhibits a two-stage variation trend of fast increase and steady increase with measurement time without loading, and an irreversible increase after loading. This results from polarization caused by ionic conduction in these composites/sensors. After reaching a plateau, the measured electrical resistance can be divided into an electrical resistance part and an electrical capacity part. The piezoresistive responses of electrical resistance part in measured electrical resistance to loading can be extracted by eliminating the linear electrical capacity part in measured electrical resistance.

Keywords

signal extraction / cement-based composites/sensors / piezoresistivity / polarization / electrical resistance / electrical capacity

References

[1] Ou J.P., Han B.G. Piezoresistive Cement-based Strain Sensors and Self-sensing Concrete Components [J]. Journal of Intelligent Material Systems and Structures, 2009, 20(3): 329-336.

[2] Mao Q.Z., Chen P.H., Zhao B.Y., . Resistance Changement of Compression Sensible Cement Speciment under Different Stresses[J]. Journal of Wuhan University of Technology, 1996, 11(3): 41-45.

[3] Han B.G., Han B.Z., Yu X. Effects of Content Level and Particle Size of Nickel Powder on the Piezoresistivity of Cement-based Composites/ Sensors [J]. Smart Materials and Structures, 2010, 19: 065012

[4] Azhari F. Cement-based Sensors for Structural Health Monitoring [D], 2008 Vancouver, Canada University of British Columbia

[5] Saad M. Effect of Temperature on Electrical Conductivity of Blended Cement Pastes [J]. Cement and Concrete Research, 1999, 29: 603-606.

[6] Han B.G., Han B.Z., Yu X. Experimental Study on the Contribution of the Quantum Tunneling Effect to the Improvement of the Conductivity and Piezoresistivity of a Nickel Powder-filled Cement-based Composite [J]. Smart Materials and Structures, 2009, 18: 065007

[7] Sun M.Q., Li Z.Q., Liu Q.P. The Electromechanical Effect of Carbon Fiber Reinforced Cement [J]. Carbon, 2000, 40(12): 2 263-2 264.

[8] Han B.G., Guan X.C., Ou J.P. Electrode Design, Measuring Method and Data Acquisition System of Carbon Fiber Cement Paste Piezoresistive Sensors [J]. Sensors and Actuators: A Physical, 2007, 135: 360-369.

[9] Mao Q.Z., Zhao B.Y., Shen D.R., . Influence of Polarization on Conductivity of Carbon Fiber Reinforced Cement[J]. Chinese Journal of Materials Research, 1997, 11(2): 195-198.

[10] Torrents J.M., Mason T.O., Peled A., . Analysis of the Impedance Spectra of Short Conductive Fiber-reinforced Composites [J]. Jour-nal of Materials Science, 2001, 36: 4 003-4 012.

[11] Tumidajski P.J. Electrical Conductivity of Portland Cement Mortars [J]. Cement and Concrete Research, 1996, 26(4): 529-543.

[12] Song G.L. Equivalent Circuit Model for AC Electrochemical Impendance Spectroscopy of Concrete [J]. Cement and Concrete Research, 2000, 30: 1 723-1 730.