Thesis

Developing resilient infrastructure for low-carbon heating : concrete linings for underground thermal energy storage (UTES) system

Downloadable Content

Download PDF
Creator
Rights statement
Awarding institution
  • University of Strathclyde
Date of award
  • 2026
Thesis identifier
  • T18103
Person Identifier (Local)
  • 202288247
Qualification Level
Qualification Name
Department, School or Faculty
Abstract
  • Underground thermal energy storage (UTES) systems offer a promising pathway for large-scale seasonal energy storage. However, the long-term structural performance and environmental impacts of subsurface infrastructure remain insufficiently understood. In mine-based UTES, shaft linings are subjected to combined geostatic and thermo-mechanical loading. At the same time, they influence operational heat losses. Material selection is critical for both system reliability and sustainability. This thesis investigates the mechanical, thermal, and environmental performance of concrete shaft lining materials for UTES. It places particular emphasis on a hybrid fibre reinforced concrete incorporating basalt and polypropylene fibres. An experimental programme characterised compressive strength, splitting tensile behaviour, crack-control response, and thermal conductivity. It is considered conventional, nominal, and hybrid fibre-reinforced concrete mixes representative of UTES shaft linings. Results show that fibre reinforcement alters failure mechanisms and cracking behaviour. This change promotes improved stress redistribution and reduces brittleness. Fibre reinforcement also influences thermal conductivity due to changes in matrix densification and interfacial bonding. These findings highlight trade-offs between mechanical performance enhancement and thermal behaviour that directly affect UTES operation. A UTES-specific life-cycle assessment (LCA) framework was developed to assess the environmental implications of these material-level differences. The analysis used a cradle-to-operation system boundary (A1–A3 + B1). Experimentally measured thermal conductivity values were included in use-phase modelling to quantify operational heat losses from shaft linings. LCA results indicate that raw material production, particularly cement manufacture, dominates environmental impacts. Use-phase impacts are sensitive to assumptions about lining thermal performance and energy supply. The analysis reveals trade-offs between increased embodied emissions from fibre reinforcement and changes in operational energy demand. The novelty of this research is not in developing a new LCA theory. Instead, it lies in creating a UTES-specific assessment framework that integrates experimental material performance with system-level environmental evaluation. By linking material-scale behaviour to operational and environmental outcomes, this thesis offers a stronger basis for evaluating and comparing lining materials for sustainable underground thermal energy storage systems.
Advisor / supervisor
  • Yang, Shangtong
Resource Type
DOI

Relations

Items

Thumbnail Title Date Uploaded Visibility Actions
file details PDF of thesis T18103 2026-08-11 Public Download