Frost resistance of rock materials

- Volumetric strain of rock material due to ice formation is presented.
- The coefficient αr defining the relative content of freezing water is determined
- A potential range of rock frost resistance is determined on the basis of coefficient αr and volumetric capillary absorption.

A precise classification of rock raw materials with respect to frost-resistance is still an issue. The knowledge of the rock's origin and its mineral composition and structure is not an effective diagnostic tool. This paper discusses the possibility of applying the capillary absorption and volumetric strain of a frozen rock sample for diagnostic purposes. Twenty one different volcanic, metamorphic and sedimentary rocks were used in the study. The strain caused by the phase change of water into ice was determined by the Differential Analysis of Volumetric Strains (DAVS). The following basic physical properties were also examined: porosity, absorbability, density, capillary absorption and frost resistance determined by the freeze-thaw testing. The mineral composition and microstructure of rocks were investigated using the X-ray method, derivatographic test, and microscopic observation. The (αr) coefficient has been proposed, which in certain circumstances can be considered as a material constant, defining the ratio of the mass of water causing the rock strain during the phase change to the total volume of water in the material pores. The diagnostics criteria enabling the frost-resistance prediction have been presented.