A thermal diffusivity estimation method for rock based on active infrared thermography

Accurate assessment of rock thermal diffusivity is essential across various engineering disciplines, yet conventional measurement methods often face practical challenges such as extensive sample preparation, prolonged measurement durations, and inadequate surface contact. In this study, we introduce a novel methodology utilizing Active Infrared Thermography (AIRT) to reliably measure rock thermal diffusivity, addressing these traditional limitations. Our approach leverages the non-contact, real-time, and non-destructive characteristics of AIRT, significantly enhancing measurement efficiency and applicability. Experimental evaluations conducted on dolomite, sandstone, granite, and a homogeneous Teflon reference material demonstrated thermal diffusivity values closely aligning with those obtained using standard methods. The observed thermal diffusivities were within ranges of 0.010–0.012 cm2/s for dolomite, 0.008–0.010 cm2/s for sandstone, and 0.0083–0.0182 cm2/s for granite, highlighting intrinsic material heterogeneity. Methodological considerations, such as radial heat propagation and surface emissivity effects, were notably evident in the Teflon sample (0.0013–0.019 cm2/s). This study validates the feasibility and robustness of AIRT for thermal diffusivity estimation, emphasizing its potential as a rapid, accurate, and practical alternative in geological and engineering applications. Future work focusing on refining measurement algorithms and optimizing experimental conditions is recommended to further enhance the method's precision and applicability.