Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strength
High temperatures exert a significant influence on the mechanical and fluid flow properties of rocks and minerals. In crystalline rocks, differential thermal expansion of minerals is known to induce microfracture damage leading to changes in bulk volume and tensile strength. Here we report new data...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2023-03-01
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| Series: | Heliyon |
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| Online Access: | http://www.sciencedirect.com/science/article/pii/S2405844023010782 |
| _version_ | 1797851910456213504 |
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| author | T. Alcock D. Bullen P.M. Benson S. Vinciguerra |
| author_facet | T. Alcock D. Bullen P.M. Benson S. Vinciguerra |
| author_sort | T. Alcock |
| collection | DOAJ |
| description | High temperatures exert a significant influence on the mechanical and fluid flow properties of rocks and minerals. In crystalline rocks, differential thermal expansion of minerals is known to induce microfracture damage leading to changes in bulk volume and tensile strength. Here we report new data from thermally treated core samples of Devon Granite in order to constrain the interplay between tensile strength and thermally-induced damage with respect to the background mineralogy. A series of core samples was cyclically heated at temperatures ranging from 25 to 800 °C, with P-wave velocity and porosity measured after each cycle. Tensile strength decreased significantly from 9 MPa to less than 3 MPa as thermal treatment increased from 25 to 800 °C. The mechanical data were then compared to fracture density values obtained by optical maps of microfracture damage to assess the quantity and degree of linkage of intergranular and intragranular fractures using the FraqPaQ toolbox. The fracture density increased from 0.02 mm−2 to 2.0 mm−2 which is consistent with results obtained from direct physical parameters as calculated from elastic wave data. We conclude that the combined effects of thermal expansion and the α−β phase transition within quartz crystals has a pronounced effect on tensile strength. |
| first_indexed | 2024-04-09T19:24:24Z |
| format | Article |
| id | doaj.art-568e42f6b86a428d88b1409da5fedfae |
| institution | Directory Open Access Journal |
| issn | 2405-8440 |
| language | English |
| last_indexed | 2024-04-09T19:24:24Z |
| publishDate | 2023-03-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Heliyon |
| spelling | doaj.art-568e42f6b86a428d88b1409da5fedfae2023-04-05T08:18:06ZengElsevierHeliyon2405-84402023-03-0193e13871Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strengthT. Alcock0D. Bullen1P.M. Benson2S. Vinciguerra3Department of Earth Sciences, University of Turin, ItalyRock Mechanics Laboratory, School of Earth and Environmental Sciences, University of Portsmouth, UKRock Mechanics Laboratory, School of Earth and Environmental Sciences, University of Portsmouth, UKDepartment of Earth Sciences, University of Turin, Italy; Corresponding author.High temperatures exert a significant influence on the mechanical and fluid flow properties of rocks and minerals. In crystalline rocks, differential thermal expansion of minerals is known to induce microfracture damage leading to changes in bulk volume and tensile strength. Here we report new data from thermally treated core samples of Devon Granite in order to constrain the interplay between tensile strength and thermally-induced damage with respect to the background mineralogy. A series of core samples was cyclically heated at temperatures ranging from 25 to 800 °C, with P-wave velocity and porosity measured after each cycle. Tensile strength decreased significantly from 9 MPa to less than 3 MPa as thermal treatment increased from 25 to 800 °C. The mechanical data were then compared to fracture density values obtained by optical maps of microfracture damage to assess the quantity and degree of linkage of intergranular and intragranular fractures using the FraqPaQ toolbox. The fracture density increased from 0.02 mm−2 to 2.0 mm−2 which is consistent with results obtained from direct physical parameters as calculated from elastic wave data. We conclude that the combined effects of thermal expansion and the α−β phase transition within quartz crystals has a pronounced effect on tensile strength.http://www.sciencedirect.com/science/article/pii/S2405844023010782Devon GraniteThermal treatmentBrazil tensile strengthFracture density |
| spellingShingle | T. Alcock D. Bullen P.M. Benson S. Vinciguerra Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strength Heliyon Devon Granite Thermal treatment Brazil tensile strength Fracture density |
| title | Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strength |
| title_full | Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strength |
| title_fullStr | Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strength |
| title_full_unstemmed | Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strength |
| title_short | Temperature-driven micro-fracturing in granite: The interplay between microstructure, mineralogy and tensile strength |
| title_sort | temperature driven micro fracturing in granite the interplay between microstructure mineralogy and tensile strength |
| topic | Devon Granite Thermal treatment Brazil tensile strength Fracture density |
| url | http://www.sciencedirect.com/science/article/pii/S2405844023010782 |
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