Effect of nano-CaCO₃ on hydration of cement containing supplementary cementitious materials

Abstract

/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/10.1680/adcr.9.00016Advances in Cement Research, 23, 1, pp. 1-29, 2011-01-01 Effect of nano-CaCO3 on hydration of cement containing supplementary cementitious materials Sato, T.; Beaudoin, J. J.

Increased Use of Fly Ash in Hydraulic Cement Concrete (HCC) for Pavement Layers and Transportation Structures

“…As has been observed previously (Sato & Beaudoin, 2011), the ability of nano-limestone to accelerate the reactions at early ages is clearly indicated in the isothermal calorimetry curves in Figure 3.6, where the curve with the nano-limestone is shifted more than 3 h to the left with respect to the 40% fly ash (no limestone) curve. This acceleration in time is also accompanied by an increase in height of the main hydration peak, particularly of the second hump of the peak corresponding to renewed reaction of the aluminate phases.…”

“…As shown in Figure 3.4, this also resulted in a 12% increase in the 1 d mortar cube compressive strength, while strengths at later ages were similar in the two systems. For the particular cement and fly ash combination selected for this study, there is a measurable influence of limestone fineness on early-age performance, as has been observed previously (Sato & Beaudoin, 2011). The first demonstration of this effect can be found in comparing results for the 55:40:5 blends prepared with either the nano-limestone or the 4.4 mm limestone powder, with equivalent HRWRA dosages.…”

“…These initial efforts with the rapid set cement were supplemented by evaluation of the use of (fine) limestone fillers to reduce the extended setting times of the HVFA mixtures, based on some recent results of Canadian and European research groups (De Weerdt, Kjellsen, Sellevold, & Justnes, 2011;Sato & Beaudoin, 2011). This part of the research program has been summarized in a manuscript that has been published in Cement and Concrete Composites .…”

“…It is recognized that the measurement of the PSD of the nano-limestone powder in this manner is severely limited by the agglomeration of the nano-sized particles and that the actual particles are likely much smaller than the sizes indicated by the curve in Figure 2.2. Previously, microscopy techniques have been employed to determine that the ''true'' particle sizes of this nanolimestone are in the range of 50 nm to 120 nm (Sato & Beaudoin, 2011). Following a dispersion technique developed by Sato, Daillo, and Trischuk (2011), laser diffraction has yielded a somewhat finer PSD than shown in Figure 2.2, with a median particle diameter of 180 nm.…”

Effect of Nano-CaCO₃ on Compressive Strength Development of High Volume Fly Ash Mortars and Concretes

“…Elsewhere, Sato and Beaudoin (2011) carried out an investigation on the incorporation of micro-and nanoCaCO 3 with high volume of supplementary cementitious materials. In that experiment, cement was replaced with 50% fly ash and 50% slag and incorporated with 10 and 20% of micro-and nano-CaCO 3 by weight of the binders.…”