An investigation of thermal effects on micro-properties of granite by X-ray CT technique. (25th July 2018)

• Record Type: Journal Article
• Authors: Fan, L.F.; Gao, J.W.; Wu, Z.J.; Yang, S.Q.; Ma, G.W.
• Is Part Of: Applied thermal engineering. Volume 140(2018)
• Page Start: 505
• Page End: 519
• Publication Date: 2018-07-25
• Subjects: Thermal effect -- X-ray Computed Tomography (CT) technique -- Porosity -- Heterogeneity -- Anisotropy; Heat engineering -- Periodicals; Heating -- Equipment and supplies -- Periodicals; Periodicals; 621.40205
• DOI: 10.1016/j.applthermaleng.2018.05.074
• Languages: English
• ISSNs: 1359-4311

Abstract

Highlights: Temperature significantly influence the micro-properties of granite. Volumetric porosity increases as temperature increases between 400 °C and 800 °C. Heterogeneity and anisotropy of granite are dominated by initial cracks below 200 °C. Granite is nearly homogeneous and isotropic when temperature is sufficiently high (e.g. 1000 °C). Abstract: The thermal effects on micro-properties of granite were experimentally studied. The volumetric porosity was observed by the X-ray Computed Tomography (CT) technique and three-dimensional (3D) image reconstruction. Two indexes (heterogeneity coefficient and anisotropy coefficient) were proposed to describe the micro-properties of granite. The thermal effects on these two indexes were discussed. The results shows that micro-porosity increases as temperature increases between 400 °C and 800 °C. It is slightly influenced by temperature beyond this range. Both of the heterogeneity and anisotropy of thermal treated granite increase to their maximums as temperature increases to 500 °C, than decrease to constants as temperature further increases. The heterogeneity and anisotropy of granite are mainly dominated by the initial cracks below 200 °C. The thermal induced cracks are mainly in the regions of lower density mineral grains below 400 °C. Boundary cracks and trans-granular cracks generate significantly above 500 °C.