부산대학교 도서관

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.cemconres.2006.02.014 Byline: Graziella Bernardo, Antonio Telesca, Gian Lorenzo Valenti Keywords: Hydration; Characterization; Mercury porosimetry; Pore size distribution; Sulfoaluminate cement Abstract: Calcium sulfoaluminate and Portland cement pastes, both prepared with a water/solid mass ratio equal to 0.5 and cured for time periods comprised between 2h and 28days, show completely different pore size distributions by mercury intrusion. Portland cement pastes aged at 12h and 1day exhibit a unimodal distribution of pore sizes related to a continuous network of capillary pores with a threshold pore radius decreasing from nearly 650 to 350nm. After 7 and 28days of curing, this parameter shifts to about 150nm and a region having smaller pores appears (with a second threshold pore radius roughly comprised between 10 and 30nm), made discontinuous by blockages of hydration products which occlude the interconnected pore system and isolate the interior space. For calcium sulfoaluminate cement pastes, a bimodal distribution is rapidly established, in which the regions with a lower porosity (threshold pore radii up to about 25nm) are dominant, while the decrease of total porosity almost ceases at later ages. The porosimetric behaviour of calcium sulfoaluminate-based cement is related to its very fast hydration rate and to the lack of water needed to continue the hydration reactions. Author Affiliation: Dipartimento di Ingegneria e Fisica dell'Ambiente, Facolta di Ingegneria, Universita degli Studi della Basilicata Via dell'Ateneo Lucano, 10, 85100 Potenza, Italy Article History: Received 3 December 2004; Accepted 21 February 2006