Compression sensibility of magnetic-concentrated fly ash mortar under uniaxial loading

Abstract

The electrical conductivity, compression sensibility, workability and cost are factors that affect the application of conductive smart materials in civil structures. Consequently, the resistance and compression sensibility of magnetic-concentrated fly ash (MCFA) mortar were investigated using two electrode method, and the difference of compression sensibility between MCFA mortar and carbon fiber reinforced cement (CFRC) under uniaxial loading was studied. Factors affecting the compression sensibility of MCFA mortar, such as MCFA content, loading rate and stress cycles, were analyzed. Results show that fly ash with high content of Fe₃O₄ can be used to prepare conductive mortar since Fe₃O₄ is a kind of nonstoichiometric oxide and usually acts as semiconductor. MCFA mortar exhibits the same electrical conductivity to that of CFRC when the content of MCFA is more than 40% by weight of sample. The compression sensibility of mortar is improved with the increase of MCFA content and loading rate. The compression sensibility of MCFA mortar is reversible with the circling of loading. Results show that the application of MCFA in concrete not only provides excellent performances of electrical-functionality and workability, but also reduces the cost of conductive concrete.

Keywords

magnetic-concentrated fly ash (MCFA) / compression sensibility / uniaxial loading / resistance / electrical resistivity

References

[1] Zheng L., Li Z., Song X., . Deformation Resistance Effect of PAN-based Carbon Fibers[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2009, 24(3): 415-417.

[2] Wang W., Dai H., Wu S. Mechanical Behavior and Electrical Property of CFRC Strengthened RC Beams under Fatigue and Monotonic Loading[J]. Materials Science and Engineering, 2008, 479(1–2): 191-196.

[3] Bontea D.-M., Chung D.D.L., Lee G.C. Damage in Carbon Fiber Reinforced Concrete, Monitored by Electrical Resistance Measurement[J]. Cement and Concrete Research, 2000, 30(4): 651-659.

[4] Wen S., Chung D. Damage Monitoring of Cement Paste by Electrical Resistance Measurement[J]. Cement and Concrete Research, 2000, 30(11): 1 979-1 982.

[5] Wang C., Liu Fuling. Damage Self-diagnoses Feasibility of Fiber-reinforced Concrete Structure[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2010, 25(2): 319-324.

[6] Chen B., Liu J. Damage in Carbon Fiber-reinforced Concrete, Monitored by Both Electrical Resistance Measurement and Acoustic Emission Analysis[J]. Construction and Building Materials, 2008, 22(11): 2 196-2 201.

[7] Wang C., Li K., Li H., . Influence of CVI Treatment of Carbon Fibers on the Electromagnetic Interference of CFRC Composites[J]. Cement and Concrete Composites, 2008, 30(6): 478-485.

[8] Lataste J.F., Behloul M., Breysse D. Characterisation of Fibres Distribution in a Steel Fibre Reinforced Concrete with Electrical Resistivity Measurements[J]. NDT and E International, 2008, 41(8): 638-647.

[9] Sun M., Mu X., Hou Z., . Experimental Studies on the Indoor Electrical Floor Heating System with Carbon Black Mortar Slabs[J]. Energy and Buildings, 2008, 40(6): 1 094-1 100.

[10] Fan Xiaoming. Effects of Environmental Temperature and Humidity on the Electrical Properties of Carbon Fiber Graphite Cement Mortar[J]. Advanced Materials Research, 2011, 143(2): 1 022-1 026.

[11] Kukier U., Ishak C. F., Sumner M. E., . Composition and Element Solubility of Magnetic and Non-Magnetic Fly Ash Fractions[J]. Environmental Pollution, 2003, 123(2): 255-266.

[12] Kutchko B. G., Kim A. G. Fly Ash Characterization by SEMEDS[ J]. Fuel, 2006, 85(17–18): 2 537-2 544.

[13] Qian J., Li C., Tang Z., . Experimental Study on Electric Conductive Concrete Made from Steel Slag Quenching with Wind[J]. Journal of Building Materials, 2005, 8(3): 233-236.

[14] Jiang C., Li Z., Song X., . Mechanism of Functional Responses to Loading of Carbon Fiber Reinforced Cementbased Composites[J]. Journal of Wuhan University of Technology-Mater. Sci. Ed., 2008, 23(4): 571-573.

[15] Jing X., Wu Yao. Current Distribution in Reinforced Concrete Cathodic Protection System with Conductive Mortar Overlay Anode[J]. Construction and Building Materials, 2009, 23(6): 2 220-2 226.

[16] Han B., Ou Jinping. Humidity Sensing Property of Cements with Added Carbon[J]. New Carbon Materials, 2008, 23(4): 382-384.

[17] Yao W., Wang Ruiqing. Transport Properties of Carbon Fiber Reinforced Cement-based Composites Subjected to External Electric Field[J]. Journal of the Chinese Ceramic Society, 2008, 36(1): 73-77.

[18] Jing X., Wu Y., Ruiqing Wang. Nonlinear Conduction in Carbon Fiber Reinforced Cement Mortar[J]. Cement and Concrete Composites, 2011, 33(3): 444-448.