Performance of phase change cementitious composites with self-heating capacity

Energy consumption remains a global challenge, with the construction sector being a significant contributor. Phase Change Materials (PCM) are introduced in construction to store heat energy and regulate temperature, reducing the reliance on air conditioners. Concrete is an ideal carrier for PCM, making PCM concrete a promising solution for energy savings and sustainable development. This study focuses on the performance of shape-stabilised PCM composites (SSPCM). The first research emphasises the structural variation of supporting materials, ceramsite as coarse aggregate, and its impact on PCM loading, leakage prevention, and strength. Ceramsite with interconnected small pores are identified as advantageous. These structures promote a stable composite state, with PCM loss between 1% and 3%. A higher strength of SSPCM composites at room temperature indicates that weak SSPCM is not a universal cause of reduced PCM concrete strength. Given the broader applicability of fine aggregates, expanded perlite is used as a carrier, with a eutectic inorganic hydrated salt as the core PCM. Experiments investigate the impact of these materials on concrete’s physical properties. The study offers a novel explanation for mechanical changes from a thermal perspective, considering factors like the PCM’s chemical properties, its role in regulating hydration heat, and its compatibility with the cement matrix. New insights emphasise the PCM’s influence on concrete performance. To improve thermal convection efficiency, multi-dimensional carbon materials are incorporated into the PCM concrete. Thermal regulation shows a temperature difference of 1.6 °C within an hour, with a time lag of 10 to 20 minutes. While PCM concrete faces challenges with weak mechanical properties, a novel carbon additive formulation enhances strength by 24%. The synergistic effect of various carbon additives proves essential in improving both the thermal and mechanical properties of PCM concrete, highlighting the potential of optimised additive combinations. The research also explores multifunctional concrete. While PCM concrete passively regulates temperature, combining it with active self-heating capabilities improves performance under varying temperature conditions. In experiments, the temperature of concrete increases by over 30 °C. The study also examines the electrical properties of the concrete using alternating-current impedance. Furthermore, hydrated salt-based SSPCMs improve conductivity by releasing free ions at elevated temperatures, further boosting the concrete’s thermal and electrical performance. In summary, this study enhances the functionality of PCM concrete by investigating its key capabilities. Through comprehensive analysis, the research offers valuable insights and recommendations for optimising PCM concrete’s performance and expanding its potential applications.

Author dc:creator

• Wang, Xiaonan

Statement dc:rights

• info:eu-repo/semantics/openAccess
• The author owns the copyright in this thesis including all reproduction and reuse rights for the work. The work may not be altered without the permission of the copyright owner. Attribution is essential when quoting or paraphrasing from this thesis.
• © 2024 Xiaonan Wang
• au.edu.uts.lib/cph

Language dc:language.iso

en_US

Handle dc:identifier.uri

http://hdl.handle.net/10453/187503

OAI identifier oai:identifier

oai:opus.lib.uts.edu.au:10453/187503