Concrete science is a multidisciplinary area of research where nanotechnology potentially offers the opportunity to enhance the understanding of concrete behavior, to engineer its properties and to lower production and ecological cost of construction materials. Recent work at the National Research Council Canada in the area of concrete materials research has shown the potential of improving concrete properties by modifying the structure of cement hydrates, addition of nanoparticles and nanotubes and controlling the delivery of admixtures. This article will focus on a review of these innovative achievements.

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1111/j. 1551-2916.2009.03055.x Journal of the American Ceramic Society, 92, 6, pp. 1303Society, 92, 6, pp. -1310Society, 92, 6, pp. , 2009 Growth of cement hydration products on single walled carbon nanotubes Makar, J. M.; Chan, G. W. The material in this document is covered by the provisions of the Copyright Act, by Canadian laws, policies, regulations and international agreements. Such provisions serve to identify the information source and, in specific instances, to prohibit reproduction of materials without written permission. For more information visit http://laws.justice.gc.ca/en/showtdm/cs/C-42Les renseignements dans ce document sont protégés par la Loi sur le droit d'auteur, par les lois, les politiques et les règlements du Canada et des accords internationaux. Ces dispositions permettent d'identifier la source de l'information et, dans certains cas, d'interdire la copie de documents sans permission écrite. Pour obtenir de plus amples renseignements : http://lois.justice.gc.ca/fr/showtdm/cs/C-42 Growth of Cement Hydration Products on Single Walled Carbon Nanotubes AbstractSingle walled carbon nanotubes (SWCNT) were distributed on the surface of ordinary Portland cement (OPC) grains. The OPC/SWCNT composite was then hydrated at a 0.5 w/c ratio. The effects of the SWCNT on the early hydration process were studied using isothermal conduction calorimetry, high resolution scanning electron microscopy and thermogravimetric analysis. The observed behaviour of the composite samples was compared to both OPC sonicated without SWCNT and previously published data on as-delivered OPC. The SWCNT were found to accelerate the hydration reaction of the C 3 S in the OPC. The morphology of both the initial C 3 A and the C 3 S hydration products were found to be affected by the presence of the SWCNT. In particular, the nanotubes appeared to act as nucleating sites for the hydration products, with the nanotubes becoming rapidly coated with C-S-H. The resulting structures remained on the surface of the cement grains while those in the sonicated and as-delivered OPC samples grew out from the grain surfaces to form typical C-S-H clusters. Classical evidence of reinforcing behaviour, in the form of fiber pullout of the SWCNT bundles, was observed by 24 hours of hydration.

Hydration of tricalcium silicate in the presence of synthetic calciumsilicate-hydrate Alizadeh, Rouhollah; Raki, Laila; Makar, Jon M.; Beaudoin, James J.; Moudrakovski, Igor http://www.nrc-cnrc.gc.ca/irc H ydra t ion of t ric a lc ium silic a t e in t he pre se nc e of synt he t ic c a lc iumsilic a t e -hydra t e NRCC-51324Alizadeh, R.; Raki, L.; Makar, J.M.; Beaudoin, J.J.; Moudrakovski, I. September 2009A version of this document is published in / Une version de ce document se trouve dans:Journal of Materials Chemistry, v. 19, no. 33, September 9, 2009, pp. 1-19, DOI: 10.1039 /B910216GThe material in this document is covered by the provisions of the Copyright Act, by Canadian laws, policies, regulations and international agreements. Such provisions serve to identify the information source and, in specific instances, to prohibit reproduction of materials without written permission. For more information visit http://laws.justice.gc.ca/en/showtdm/cs/C-42Les renseignements dans ce document sont protégés par la Loi sur le droit d'auteur, par les lois, les politiques et les règlements du Canada et des accords internationaux. Ces dispositions permettent d'identifier la source de l'information et, dans certains cas, d'interdire la copie de documents sans permission écrite. Pour obtenir de plus amples renseignements : http://lois.justice.gc.ca/fr/showtdm/cs/C-42 AbstractThe early age hydration of tricalcium silicate, the main chemical compound in Portland cement, was studied in the presence of synthetic calcium silicate hydrate (C-S-H) addition having C/S ratios=0.8 and 1.2. Isothermal conduction calorimetry, scanning electron microscopy, differential scanning calorimetry and 29 Si MAS NMR were employed in order to investigate events occurring during various stages of the hydration. The results that were analyzed using novel methods in cement chemistry showed that the addition of seeds of synthetic C-S-H significantly accelerated the hydration of C 3 S. The extent of the acceleration was dependant on the amount and chemical composition of the C-S-H seeds. It was suggested that the synthetic C-S-H significantly increased the rate and degree of dissolution of the C 3 S particles.It was also found that the nucleation and silicate polymerization of the C-S-H that formed during the hydration of the C 3 S phase was promoted. Direct evidence of the seeding effect was provided. The properties of the resulting C-S-H hydration products seemed to be dependant on the lime to silica ratio of the synthetic C-S-H. It was suggested that the silicate polymerization and chemical composition of the hydration products of silicate phases may be manipulated through C-S-H seeding. As the chemical and mechanicalproperties of C-S-H are largely controlled by its C/S ratio, this method should provide a unique tool for tailoring the nanostructure of the hydration products of Portland cement through the addition of selective C-S-H seeds for optimum engineering and durability performance.Keywords: Tricalcium Silicate (C 3 S), Calcium Silicate Hy...

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at

/npsi/ctrl?lang=en http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/ctrl?lang=fr Access and use of this website and the material on it are subject to the Terms and Conditions set forth at http://nparc.cisti-icist.nrc-cnrc.gc.ca/npsi/jsp/nparc_cp.jsp?lang=en NRC Publications Archive Archives des publications du CNRCThis publication could be one of several versions: author's original, accepted manuscript or the publisher's version. / La version de cette publication peut être l'une des suivantes : la version prépublication de l'auteur, la version acceptée du manuscrit ou la version de l'éditeur. For the publisher's version, please access the DOI link below./ Pour consulter la version de l'éditeur, utilisez le lien DOI ci-dessous.http://dx.doi.org/10.1111/j. 1551-2916.2008.02304.x Journal of the American Ceramic Society, 91, 4, pp. 1292Society, 91, 4, pp. -1299Society, 91, 4, pp. , 2008 End of the induction period in ordinary Portland cement as examined by high resolution scanning electron microscopy Makar, J. M.; Chan, G. W.http://irc.nrc-cnrc.gc.caEnd of the induction period in ordinary Portland cement as examined by highresolution scanning electron microscopy NRCC-49236Makar, J.M.; Chan, G.W.A version of this document is published in / Une version de ce document se trouve dans: Journal of the American Ceramic Society, v. 91, no. 4, April 2008, pp. 1292-1299 doi: 10.1111/j.1551-2916.2008 The material in this document is covered by the provisions of the Copyright Act, by Canadian laws, policies, regulations and international agreements. Such provisions serve to identify the information source and, in specific instances, to prohibit reproduction of materials without written permission. For more information visit http://laws.justice.gc.ca/en/showtdm/cs/C-42Les renseignements dans ce document sont protégés par la Loi sur le droit d'auteur, par les lois, les politiques et les règlements du Canada et des accords internationaux. Ces dispositions permettent d'identifier la source de l'information et, dans certains cas, d'interdire la copie de documents sans permission écrite. Pour obtenir de plus amples renseignements : http://lois.justice.gc.ca/fr/showtdm/cs/C-42 AbstractThe early stages of ordinary Portland cement (OPC) hydration were studied by cold field emission scanning electron microscopy and isothermal conduction calorimetry. Particular attention was paid to samples from the end of the induction period, where an additional peak in the tricalcium silicate hydration reaction has recently been discovered. Higher resolution images were obtained than is possible with current in-situ imaging techniques, allowing for the observation of features on the 5 nanometer scale. The peak in the hydration at the end of the induction period was associated with both the formation of pores in the surface of the cement grains and the formation of nanoscale C-S-H structures on those surfaces. The effects of grinding of OPC and additions of tricalcium aluminate and tetracalcium aluminoferrite on the peak at the end of the induction p...