PROCEEDINGS OF THE RUSSIAN HIGHER SCHOOL
ACADEMY OF SCIENCES

In the study, various rocks were heated to raise the values up to a temperature of 250 ° C, to determine the values of loss of strength and changes in physical properties, during thermal cycles. As a result of thermal stresses, micro-cracks or visible macro-cracks appear, which lead to noticeable loss of strength depending on various factors such as temperature, heating duration, cooling details and some rock properties such as mineralogical composition, grain size, porosity, microcracks before heating, process [2, 5]. The reason for the loss of strength during heating and cooling, variations in the deformation of various minerals cause cracking in the contacts of the minerals and the propagation of existing cracks.

This situation causes the physical weathering of rock materials. In addition, chemical weathering at high temperatures should be noted as one of the main causes of loss of strength due to thermal changes. In physical weathering, the mineralogical composition of rocks and the temperature level are the determining parameters for chemical weathering. Since temperatures in this study are generally not critical for the onset of chemical weathering, the study focused on physical weathering rather than chemical weathering.

1. GOST 26450.1–85. Porody gornye. Metod opredeleniya koeffitsienta otkrytoi poristosti zhidkostenasyshcheniem [State standard GOST 26450.1–85. Rocks. Method for determination of open porosity coefficient by fluid saturation]. Moscow, Standards Publ., 1985.
2. Kryukov G.M. Fizika razrusheniya gornykh porod pri burenii i vzryvanii [Physics of destruction of rocks during drilling and blasting]. Moscow, Gornaya kniga Publ., 2006. 329 p.
3. Rzhevskii V.V. Osnovy fiziki gornykh porod [Fundamentals of rock physics]. Moscow, Nedra Publ., 1978. 390 p.
4. Gabrielyants G.A. Geologiya neftyanykh i gazovykh mestorozhdenii [Geology of oil and gas fields]. 3rd ed. Moscow, Nedra Publ., 1984. 285 p.
5. Eremenko N.A., ed. Spravochnik po geologii nefti i gaza [Handbook of oil and gas geology]. Moscow, Nedra Publ., 1984. 480 p.
6. Kuznetsov V.G. Litologiya. Osadochnye gornye porody i ikh izuchenie [Lithology. Sedimentary rocks and their study]. Moscow, Nedra-Biznestsentr Publ., 2007. 511 p.