The authors recently investigated the use of conductive concrete to enhance nondestructive evaluation (NDE) capa- bilities. Preliminary results have shown that a conductive concrete can facilitate the utilization of an eddy current technique, where damages in a conductive specimen were easier to detect compared with a non-conductive substrate. While such results demonstrated the promise of using conductive concrete to facilitate and potentially accelerate the NDE process, the fabrication of an homogeneous conductive concrete is technically or economically challenging, depending on the conductive filler used in the process. In this paper, we propose a new cementitious composite to accelerate NDE. The composite uses inexpensive carbon black particles (CB) and a block-copolymer. The purpose of the block co-polymer, a styrene-ethylene-butylene-styrene (SEBS), is to facilitate the creation of conductive chains, therefore reducing the necessary concentration of conductive filler required to achieve electrical percolation. Several cementitious composite specimens of various concentrations of CB are fabricated, and results show that the utilization of SEBS reduces the electrical percolation threshold by approximately 50% with a gain on electrical conductivity relative to a non-conductive specimen mix of approximately 33%. Strain-sensing tests also demonstrate that SEBS-based specimens have good sensing properties, but lag behind those of conductive concrete specimens fabricated with CB only.
1. L. Materazzi, F. Ubertini, A. D’Alessandro, Carbon nanotube cement-based transducers for dynamic sensing of strain, Cement and Concrete Composites 37 (2013) 2 – 11.
2. O. Galao, F. Baeza, E. Zornoza, P. Garc´es, Strain and damage sensing properties on multifunctional cement composites with cnf admixture, Cement and Concrete Composites 46 (2014) 90–98.
3. F. Ubertini, A. L. Materazzi, A. DAlessandro, S. Laflamme, Natural frequencies identification of a reinforced concrete beam using carbon nanotube cement-based sensors, Engineering Structures 60 (2014) 265–275.
4. DAlessandro, F. Ubertini, S. Laflamme, A. L. Materazzi, Towards smart concrete for smart cities: Recent results and future application of strain-sensing nanocomposites, Journal of Smart Cities 1 (1).
5. S. A. Yehia, C. Y. Tuan, Thin conductive concrete overlay for bridge deck deicing and anti-icing, Transportation Research Record: Journal of the Transportation Research Board 1698 (1) (2000) 45–53.
6. P. Tumidajski, P. Xie, M. Arnott, J. Beaudoin, Overlay current in a conductive concrete snow melting system, Cement and concrete research 33 (11) (2003) 1807–1809.
7. S. Wu, L. Mo, Z. Shui, Z. Chen, Investigation of the conductivity of asphalt concrete containing conductive fillers, Carbon 43 (7) (2005) 1358–1363.
8. O. Lourie, D. Cox, H. Wagner, Buckling and collapse of embedded carbon nanotubes, Physical Review Letters 81 (8) (1998) 1638.
9. S. Laflamme, H. S. Saleem, B. K. Vasan, R. L. Geiger, D. Chen, M. R. Kessler, K. Rajan, Soft elastomeric capacitor network for strain sensing over large surfaces, IEEE/ASME Transactions on Mechatronics 18 (6) (2013) 1647–1654.
10. J.-C. Huang, Carbon black filled conducting polymers and polymer blends, Advances in Polymer Technology 21 (4) (2002) 299–313.
11. S. Wen, D. Chung, Piezoresistivity in continuous carbon fiber cement-matrix composite, Cement and Concrete Research 29 (3) (1999) 445–449.
12. W. McCarter, G. Starrs, T. Chrisp, Electrical conductivity, diffusion, and permeability of portland cement-based mortars, Cement and Concrete Research 30 (9) (2000) 1395–1400.
13. M. H. Al-Saleh, U. Sundararaj, An innovative method to reduce percolation threshold of carbon black filled immiscible polymer blends, Composites Part A: Applied Science and Manufacturing 39 (2) (2008) 284–293.
14. F. Gubbels, R. J´erˆome, P. Teyssie, E. Vanlathem, R. Deltour, A. Calderone, V. Parente, J.-L. Br´edas, Selective lo- calization of carbon black in immiscible polymer blends: a useful tool to design electrical conductive composites, Macromolecules 27 (7) (1994) 1972–1974.
15. S. Laflamme, I. Pinto, M. Elkashef, K. Wang, E. W. Cochran, F. Ubertini, Conductive paint-filled cement paste sensor for accelerated percolation, in: Proc. of SPIE, 2015.
46 Page Views
0 PDF Downloads
0 Facebook Shares