Issue 18

G. Ferro et alii, Frattura ed Integrità Strutturale, 18 (2011) 34-44; DOI: 10.3221/IGF-ESIS.18.04 34 Carbon nanotubes cement composites Giuseppe Ferro Politecnico di Torino, Department of Structural Engineering and Geotechnics, 10129 Torino, Italy Jean-Marc Tulliani Politecnico di Torino, Department of Materials Science and Chemical Engineering, 10129 Torino, Italy Simone Musso Department of Physics, Politecnico di Torino, 10129 Torino, Italy MIT - Department of Civil and Environmental Engineering, Cambridge, MA, 02139, USA A BSTRACT . The present paper reviews the current state of the art of carbon nanotubes cement-based composites and the possible applications. The influence of carbon nanotubes additions onto cement paste mechanical and electrical properties are discussed in detail. Though promising, several challenges have still to be solved before the introduction of these new materials into the public sphere through civil infrastructures. K EYWORDS . Cement; Mortars; Hydration; Carbon nanotubes; Mechanical properties; Electrical properties. I NTRODUCTION arbon nanotubes (CNTs) are hollow tubular channels, formed either by one wall (SWCNTs, Fig. 1a) or several walls (MWCNTs, Fig. 1b), of rolled graphene sheets [1], having diameters ranging between 0.4 and 10 nm for SWCNTs or from 4 to 100 nm for MWCNTs. CNTs length is not restricted and can reach micro or even millimeter range. CNTs are not produced, however, by rolling up graphite sheets, but rather by a growth process from one end: the synthesis of SWNTs is achieved under precisely controlled conditions in the presence of a catalyst; in case of the deviation from the production route, multi-wall carbon nanotubes (MWNTs) are formed. (a) (b) Figure 1 : Illustration of SWCNTs (a) and MWCNTs (b) . The research on CNT composites has initially focused on polymer matrices, with ceramics and metals also being considered for this role. While initial results were generally disappointing, often showing little or no improvement in C

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