Measurement and Prediction of Thermal Conductivity of Volcanic Basalt Rocks from Warsak Area

Abstract

Accurate values of thermal properties of rocks are needed for a number of engineering applications starting from heat losses in buildings to underground geothermal modeling. Igneous rocks are one of the major constituents of the Earth’s crust and are formed by the crystallization and solidification of molten magma. In this work, the thermal transport properties of porous igneous basalt rocks are measured using Transient Plane Source (TPS) technique under ambient conditions with air as saturant in pore spaces. Data are presented for fifteen samples of volcanic basalt rocks having different porosity values ranging from 0.267% to 9.432% by volume, taken from the place of Warsak near Peshawar city, located in the north of Pakistan. The porosity and density parameters are measured using the American Society of Testing and Materials (ASTM) standards. The mineral compositions of the samples are analyzed by X-ray fluorescence (XRF) technique. The specific gravity is predicted using the chemical composition of basalts and is compared with the experimental results. The thermal conductivity and thermal diffusivity values of the measured samples are also predicted using the mixing law and empirical models and results are compared with the measured data. Results show that the thermal conductivity of the studies of basalt samples decreases with the increase in porosity values, whereas no significant change has been observed in the thermal diffusivity data. Measured data are significant for geothermal modeling and in predicting heat losses in buildings wherever basalt rocks are used.

Evaluation of Jordanian Basalt as a Thermal Insulation Material

“…5) and Assa's model (Eq. 8), obtaining minimum and maximum deviation percentages between -20% to 12% (Table 2); whis is remarkably different compared with previous the investigations presented by Zeb et al, (2020), where the percentage of deviation ranged between 0.40% to 33%. However, due to the crystallographic structure, porosity and thermal behaviour of mixture basaltic, the best models should be obtained experimentally within the porosity range of study interest.…”

“…The overall thermal conductivity predicted by these models is a function of the thermal conductivity of the solid basalt matrix (K s ), the fluid existing in the pores, in this case air (K f ), and porous fraction (ɛ) of the basaltic rock. Zeb et al (2020) predicted the thermal conductivity of rocks using Wiener's upper (Eq. 3) and lower bounds models (Eq.…”