Open Access

ARTICLE

Time-Resolved Experimental Analysis of Granite–Mortar Interface Permeability under High-Temperature Conditions

Wei Chen^*, Yuanteng Zhao, Yue Liang

School of Civil Engineering, Architecture and Environment, Hubei University of Technology, Wuhan, 430068, China

* Corresponding Author: Wei Chen. Email:

Fluid Dynamics & Materials Processing 2025, 21(12), 3033-3053. https://doi.org/10.32604/fdmp.2025.073778

Received 25 September 2025; Accepted 27 November 2025; Issue published 31 December 2025

Abstract

In deep underground engineering, geological disposal of nuclear waste, and geothermal development, the granite–mortar interface represents a critical weak zone that strongly influences sealing performance under high-temperature conditions. While previous studies have primarily focused on single materials, the dynamic evolution of interface permeability under thermal loading remains insufficiently understood. In this study, time-resolved gas permeability measurements under thermal cycling (20°C → 150°C → 20°C) were conducted, complemented by multi-scale microstructural characterization, to investigate the nonlinear evolution of permeability. Experimental results indicate that interface permeability at room temperature is approximately one order of magnitude higher than that of the mortar matrix. Heating to 100°C initially reduces permeability due to densification driven by thermal expansion, whereas further heating to 100–150°C induces C–S–H dehydration and thermal mismatch stresses, generating micro-cracks and reversing the permeability trend. During cooling, irreversible pore expansion further enhances permeability. After thermal cycling to 150°C, specimens with water–cement ratios of 0.3 and 0.5 exhibit permeability increases of 161.7% and 297.7%, respectively. Microstructural analysis further reveals that interface porosity increases by 73–79%, with dominant pore sizes expanding to 33–66 μm. Collectively, these findings identify 100°C as a critical threshold for abrupt permeability transitions and provide fundamental insights for optimizing the design and reliability of sealing systems in high-temperature rock engineering.

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Keywords

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