UNDERSTANDING THE EFFECT OF MICROWAVE IRRADIATION ON PHYSICAL PROPERTIES OF ROCKS USING LABORATORY TESTING AND NUMERICAL MODELING
Results of laboratory experiments investigating the response of physical properties like p-wave velocity and uniaxial compressive strength to microwave irradiation of different rock types indicate a decrease in the integrity of the investigated samples. A finite element modelling (FEM) chain was developed in order to simulating the development of thermal stresses in a granodiorite sample. The constitutive minerals: quartz, biotite and feldspar were arranged in different patterns and exposed to different external temperatures. Preliminary modeling results are in good accordance to laboratory tests, indicating that minerals with high thermal properties (coefficient of thermal expansion, thermal conductivity, and heat capacity at constant pressure) such as quartz cause high stresses to be developed along grain boundaries.