Abstract
This study involved testing heat-treated granite using natural cooling, water cooling and acid cooling methods to evaluate and compare the effect of acid cooling on the dynamic tensile behavior of thermally treated granite. The study focused on elucidating the mechanisms through which acid cooling affects the dynamic tensile properties, mineralogical composition, and thermal shock damage characteristics of thermally treated granite, while revealing the failure evolution mechanisms of specimens under acid cooling. Results showed that increasing the temperature from 100 to 600 °C significantly reduces P-wave velocity and dynamic tensile strength of acid-cooled samples, especially when compared to naturally cooled and water-cooled specimens. At 600 °C, acid-cooled specimens showed a 71.0% decrease in P-wave velocity and a 61.5% reduction in dynamic tensile strength compared to room-temperature (25 °C) specimens. XRD and EDS analyses further revealed that acid cooling synergistically accelerated mineralogical degradation through chemical corrosion and thermal stress. Additionally, granite specimens subjected to acid cooling displayed the most severe fragmentation. This study indicates that acid cooling enhances rock-breaking efficiency in hot dry rock (HDR) exploitation via thermal expansion, stress-induced damage, and chemical weakening, offering new insights for optimizing drilling technologies and controlling surrounding rock stability in geothermal engineering.
Data availability
The data used and/or analyzed during the current study available from the corresponding author on reasonable request.
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Acknowledgements
The authors would like to express their gratitude to all those who contributed to the writing of this paper.
Funding
This work was financially supported by the Major National Science and Technology Project for Deep Earth (No. 2024ZD1003804 and No. 2024ZD1003808), the science and technology innovation Program of Hunan Province (No: 2025RC1011), the Natural Science Foundation of Hunan Province (2023JJ30662) and Graduate Research Innovation Project of Hunan Province (CX20240274).
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T.Y. acquired funding, administered the project, and conceived the study. J.S. conducted the investigation, performed formal analysis and visualization, and wrote the original draft. F.L., Y.Z. and X.L. contributed to the investigation. S.L. provided validation and review. All authors reviewed and approved the final manuscript.
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Yin, T., Song, J., Liu, F. et al. Study on the dynamic tensile properties and damage mechanisms of thermally treated granite under acid cooling. Sci Rep (2026). https://doi.org/10.1038/s41598-026-37207-5
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DOI: https://doi.org/10.1038/s41598-026-37207-5
