Self sensing carbon nanotube (CNT) and nanofiber (CNF) cementitious composites for real time damage assessment in smart structures

Abstract The self sensing properties of cementitious composites reinforced with well dispersed carbon nanotubes and carbon nanofibers were investigated. The electrical resistance of cementitious nanocomposites with w/c = 0.3 reinforced with well dispersed carbon nanotubes (CNTs) and nanofibers (CNFs) at an amount of 0.1 wt% and 0.3 wt% of cement was experimentally determined and compared with resistivity results of nanocomposites fabricated with “as received” nanoscale fibers at the same loading. Results indicate that conductivity measurements, besides being a valuable tool in evaluating the smart properties of the nanocomposites, may provide a good correlation between the resistivity values measured and the degree of dispersion of the material in the matrix. The addition of CNTs and CNFs at different loadings was proven to induce a decrease in electrical resistance, with the nanocomposites containing 0.1 wt% CNTs yielding better electrical properties. Furthermore, conductivity measurements under cyclic compressive loading provided an insight in the piezoresistive properties of selected nanocomposites. Results confirm that nanocomposites, reinforced with 0.1 wt% CNTs and CNFs, exhibited an increased change in resistivity, which is indicative of the amplified sensitivity of the material in strain sensing.

[1]  D.D.L. Chung,et al.  Piezoresistivity-based strain sensing in carbon fiber-reinforced cement , 2007 .

[2]  M. Pigeon,et al.  Electrical resistivity of carbon and steel micro-fiber reinforced cements , 1992 .

[3]  Eil Kwon,et al.  Effects of CNT concentration level and water/cement ratio on the piezoresistivity of CNT/cement composites , 2012 .

[4]  T. Hou.  Wireless and Electromechanical Approaches for Strain Sensing and Crack Detection in Fiber Reinforced Cementitious Materials. , 2008 .

[5]  Eil Kwon,et al.  A carbon nanotube/cement composite with piezoresistive properties , 2009 .

[6]  Jingyao Cao,et al.  ELECTRIC POLARIZATION AND DEPOLARIZATION IN CEMENT-BASED MATERIALS, STUDIED BY APPARENT ELECTRICAL RESISTANCE MEASUREMENT , 2004 .

[7]  Jinping Ou,et al.  Electrode design, measuring method and data acquisition system of carbon fiber cement paste piezoresistive sensors , 2007 .

[8]  Meijie Tang,et al.  Reversible electromechanical characteristics of carbon nanotubes underlocal-probe manipulation , 2000, Nature.

[9]  Yi-Lung Mo,et al.  Electrical resistance of carbon-nanofiber concrete , 2009 .

[10]  Filippo Ubertini,et al.  Carbon nanotube cement-based transducers for dynamic sensing of strain , 2013 .

[11]  D.D.L. Chung,et al.  Carbon fiber reinforced concrete as an electrical contact material for smart structures , 1993 .

[12]  Satish Nagarajaiah,et al.  Nanotube film based on single-wall carbon nanotubes for strain sensing , 2004 .

[13]  D.D.L. Chung,et al.  Improving the strain-sensing ability of carbon fiber-reinforced cement by ozone treatment of the fibers , 1998 .

[14]  Nemkumar Banthia,et al.  Carbon-fiber reinforced cement based sensors , 2007 .

[15]  D.D.L. Chung,et al.  Self-monitoring of fatigue damage in carbon fiber reinforced cement , 1996 .

[16]  C. Hansson,et al.  Electrical resistivity measurements of Portland cement based materials , 1983 .

[17]  Mohamed Saafi,et al.  Wireless and embedded carbon nanotube networks for damage detection in concrete structures , 2009, Nanotechnology.

[18]  E. Kwon,et al.  A self-sensing carbon nanotube/cement composite for traffic monitoring , 2009, Nanotechnology.

[19]  Xiaohua Zhao,et al.  Pressure-sensitive properties and microstructure of carbon nanotube reinforced cement composites , 2007 .

[20]  Nemkumar Banthia,et al.  Cement-based sensors with carbon fibers and carbon nanotubes for piezoresistive sensing , 2012 .

[21]  Maria S. Konsta-Gdoutos,et al.  Multi-scale mechanical and fracture characteristics and early-age strain capacity of high performance carbon nanotube/cement nanocomposites , 2010 .

[22]  D. Chung,et al.  Carbon fiber reinforced concrete for smart structures capable of non-destructive flaw detection , 1993 .

[23]  Zhongxian Li,et al.  Application of Cement-Based Piezoelectric Sensors for Monitoring Traffic Flows , 2006 .

[24]  Eil Kwon,et al.  Fabrication of Piezoresistive CNT/CNF Cementitious Composites with Superplasticizer as Dispersant , 2012 .

[25]  Luigi Coppola,et al.  Electrical Properties of Carbon Nanotubes Cement Composites for Monitoring Stress Conditions in Concrete Structures , 2011 .

[26]  Surendra P. Shah,et al.  Carbon nanofiber cementitious composites: Effect of debulking procedure on dispersion and reinforcing efficiency , 2013 .