Acta Montanistica Slovaca (Dec 2004)
The Influence of Temperature on the Deformational and Strength Characteristics of Rocks
Abstract
The stresses generated as aresult of different thermal characteristics of particular rock components as well as the stresses generated as a result of various changes in the chemical or crystallographical rock composition at rised rock temperature are assigned as structural thermal stresses. Both the uniaxial compressive strength change and the deformational modulus change were observed at five various reference temperatures of Ruskov andesite and Hnilec granite. Structural thermal stresses, induced in the rock, increase its disturbance due to inter- and intragranular cracks initiation and the propagation on the micro- and mesoscopic level in a quite significant way. This results in both the uniaxial compressive strength and the deformational modulus decrease. The uniaxial compressive strength decrease is more significant than the longitudinal waves propagation velocity decrease, which is apparently connected with the created cracks activation at loading while determining the rock strength. It is necessary to consider the structural thermal stress influence on the deformational and strength characteristics in the quantification of all thermal treatment processes in rocks. Not considering this influence may result in the overestimating their effect on the rock or some of its characteristics.