Experimental Investigations on the Thermal Properties of Jalore Granitic Rocks for Nuclear Waste Repository

Publication date: Available online 26 August 2019Source: Thermochimica ActaAuthor(s): P.K. Gautam, A.K. Verma, T.N. Singh, Wei Hu, K.H. SinghAbstractIn this paper, the thermal properties of Jalore granitic rocks were determined using the transient plane source (TPS) technique in the temperature range from 25 °C to 250 °C. The dilatometric tests for thermal expansion and the thermal strain were carried out. The results obtained indicate that the thermal conductivity, thermal diffusivity, mass loss and elastic wave velocity of Jalore granite decreases gradually as the temperature increases from 25 °C to 250 °C. The thermal expansion increases with the increasing temperature, and there is a good increasing exponential relation between temperature and thermal strain. Additional laboratory tests including thermogravimetric (TG) and differential thermal analysis (DTA), X-ray diffraction (XRD) and scanning electron microscope (SEM) have also been conducted to investigate the temperature evolution inside the rock specimens. The results show that the feldspars have a low and isotropic thermal expansion that do not affect the structure as much in red and white granite, while on the other hand, thermal stresses are confined in quartz crystal, resulting in intense intragranular cracking for golden and black granite. This research in terms of measurement of thermal parameters subjected to below damage threshold temperature (≥ 250 °C) as well as the method of analyzing the...
Source: Thermochimica Acta - Category: Chemistry Source Type: research