3D experimental investigation of the microstructure of cement pastes using synchrotron X-ray microtomography (μCT)

Quantification of tortuosity in hardened cement pastes using synchrotron-based X-ray computed microtomography

“…Our preliminary finding also shows rough agreement with that of the microtomographic studies reported in [7]. Given the spatial resolution of 0.7-µm, Gallucci et al observe that the total porosity of a 1-day old hardened cement paste (w/c = 0.50) drops from about 0.16 to near zero after 28 days of curing; and also, the pore network does not percolate any longer after 7 days.…”

“…Accordingly, the lower end of the pore size range that can be detected in principle from microtomography is determined by its spatial resolution whereas the upper end can be as large as possible depending on the specimen size. In spite of its limited range of pore size when compared to other indirect techniques, synchrotron microtomography is, to date, the most viable noninvasive and nondestructive imaging technique that can provide directly the 3D information of the pore network that are more relevant to transport properties of hardened cement pastes [5,7,11]. This technique could therefore complement the other techniques such as that of MIP in studying microstructure-property relationship.…”

“…It has been shown from either microstructure models [33][34][35] or microtomographic studies [7] that increasing the pixel (or voxel) size decreases the computed pore connectivity. Figure 10 illustrates the effect of increasing the voxel size (i.e., digital resolution of the microtomographic images) on the segmented porosity and pore connectivity in the considered VOI of OPC50-2d.…”

“…Synchrotron-based microtomography have been used to porous building materials [4], as well as, to other cementitious materials [5][6][7][8][9] by various researchers in the US and Europe. At SPring-8, a third-generation synchrotron radiation facility in Japan, the pore structure of hardened cement pastes and mortar was also examined at a sub-micron resolution [10][11].…”

Application of X-Ray CT to Study Diffusivity in Cracked Concrete Through the Observation of Tracer Transport

“…There is, however, a trade-off, such that the maximum sample size for the higher-resolution systems is limited to less than a few millimeters, whereas specimens on the scale of a few centimeters may be used with lower resolution systems. For cement-based materials, X-ray CT has been applied to a variety of research areas including pore structure characterization and freeze-thaw damage (Bentz et al 2000;Burlion et al 2006;Gallucci et al 2007;Helfen et al 2005;Lu et al 2006;Hitomi et al 2004;Promentilla et al 2008Promentilla et al , 2009Promentilla et al , 2010Sugiyama et al 2010).…”