DBPapers
DOI: 10.5593/SGEM2014/B12/S2.067

INFLUENCE OF FROZEN AND UNFROZEN WATER IN ROCK PORES ON ROCK EXPANSION AND DETERIORATION

M. Ondrasik, M. Kopecky, M. Brcek
Wednesday 1 October 2014 by Libadmin2014

References: 14th International Multidisciplinary Scientific GeoConference SGEM 2014, www.sgem.org, SGEM2014 Conference Proceedings, ISBN 978-619-7105-08-7 / ISSN 1314-2704, June 19-25, 2014, Book 1, Vol. 2, 527-534 pp

ABSTRACT
Rock aggregates or dimensional stones as any other material used for buildings starts to deteriorate when exposed to processes of exogenous forces. The most outstanding is frost, especially repeated freezing and thawing. This process deteriorate rocks by way which is not explained sufficiently yet. The article presents results of extensive research performed on 88 rock samples focused on relationship between rock pore structure, thermodynamic properties of pore water, rock expansion on freezing of pore water and resistance of rock aggregates against frost. The results of the research proved importance of pore structure and thermodynamic properties of pore water for rock frost resistance. Rocks in which pore water did not freeze at temperature -20°C and have no frost expansion have high degree of saturation and high weight lost on freeze-thaw test. On the contrary, largest frost expansions have rocks which have low degree of saturation and large open pores. It was proved, that expansion of rocks on freezing has no influence on rock frost resistance. It is rock pore structure which must be known to understand the rock deterioration on freezing.

Keywords: rock deterioration, adsorbed water, absorbed water freezing, rock porosity, freeze-thaw loss