Experimental analysis of key factors governing effective thermal conductivity of granular media
OA Location
Author(s)
Schnaider Bortolotto, Marina
Taborda, David
O'Sullivan, Catherine
Type
Conference Paper
Abstract
Geomaterials are constantly subjected to thermal loads, which are caused by a variety of phenomena, including interaction with the atmosphere, buried cables and pipelines, and the operation of ground-source energy systems. Heat transfer within geomaterials is mainly governed by conduction. The capability of a media to conduct heat is quantified through the assessment of its thermal conductivity, which is influenced by many factors. Three main groups of factors affect the effective thermal conductivity of granular materials: particle contact, type and relative amount of pore fluid, and mineralogy. Particle contact is a broad concept that depends upon particle size, gradation (including fines content), angularity, density, and external pressure. Although there are studies investigating individual parameters, systematic studies investigating the impact of all individual factors are scarce. This contribution includes an overview of key parameters controlling the effective thermal conductivity and their significance. A new experimental dataset obtained through the use of needle probes, which are interpreted as a transient infinite-line heat source, is presented. The effect of particle contact was assessed in terms of porosity, gradation, particle size and shape. The effect of adding purified water to the pore spaces and the type of geomaterials were also assessed. The generated dataset was clearly clustered into four groups with increasing thermal conductivity: dry glass beads, dry natural sands, flushed glass beads, and flushed natural sands. Such natural clustering emphasises the dominance of the type of geomaterials and pore fluid on the effective thermal conductivity. These findings not only contribute to the fundamental understanding of thermal conductivity in porous media, but also provide more reliable parameters for simulating the thermal behaviour of the ground, leading to better design of geothermal heating/cooling systems and high voltage
cabling.
cabling.
Date Issued
2026-06-14
Date Acceptance
2026-06-14
Citation
Proceedings of the 21st ICSMGE, 2026, pp.667-672
ISBN
978-3-9503898-4-5
Publisher
ÖGG, Austrian Society for Geomechanics
Start Page
667
End Page
672
Journal / Book Title
Proceedings of the 21st ICSMGE
Copyright Statement
© 2026 The Author(s).
Source
Proceedings of the 21st ICSMGE
Publication Status
Published
Start Date
2026-06-14
Finish Date
2026-06-19
Coverage Spatial
Vienna, Austria