Enhancing Urban Energy Sustainability through PCM-Integrated Mortar Infrastructure

The escalating energy demand to regulate urban temperature is emerging as a pressing environmental issue. As societies strive for comfort and climate control, the environmental impact of excessive energy use cannot be overlooked. To mitigate this situation, this research aims to design novel mortar mixtures to regulate heat in urban spaces affected by temperature fluctuations, thereby enhancing urban energy sustainability using Phase-Change Material (PCM) and recycled crushed glass with low thermal conductivity. This study also aims to clarify contradictory findings about the impact of glass on the mechanical properties of mortar. While some studies suggest that incorporating glass improves the strength of mortar, other studies concluded strength reduction. Furthermore, by substituting natural sand with recycled glass, this study also addresses the importance of preserving natural resources. Initially, thermal efficiency and mechanical strength have been measured after fabricating mortar mixtures with partial mass replacements of sand with PCM (e.g., 2%, 4%, 6%, and 10%) and with recycled crushed glass (e.g., 5%, 10%, 15%, and 20%). Since 6% PCM replacement showed a strength level within the target limit (i.e., 12-17 Mpa) of any practical application, the amount of PCM replacement has been extended to 10% to evaluate both the maximum thermal benefit and the most critical strength reduction of PCM-modified mortars. Thereafter, combined mortar mixtures have been prepared based on preliminary results obtained with varying levels of PCM (e.g., 2%, 4%, and 6%) and glass (e.g., 5%, 10%, and 15%). All samples (e.g., PCM mortar, Glass mortar, and Glass-PCM mortar) were tested for workability, density, air content, compressive and flexural strength, thermal conductivity, specific heat capacity, surface resistivity, and water absorption. The optimized mix, P6G15 (i.e., 6% PCM and 15% Glass), demonstrated the best combined thermos-mechanical performance. It achieved a compressive strength of 29.8 Mpa. In terms of thermal conductivity there is a reduction of ~ 40% (0.6 w/mK), ~ 60% improvement in resistance and ~ 58% improvement in heat storage capacity than the control mix. The durability properties tests indicated higher surface resistivity (25.2 kΩ·cm), and reduction in void content (8.1%) with lower water absorption (3.3%). P4G15 also exhibited a well-balanced enhancement in both mechanical strength and thermal performance. It achieved a compressive strength of 35.2 MPa, which is higher than the optimized mix (P6G15). Thermally, it showed ~ 30% reduction in conductivity, ~ 40% improvement in resistance and ~ 54% improvement in heat storage capacity than the control mix. The durability properties also showed 11% improvement in surface resistivity than the control mix. These findings show that the synergistic use of PCM and recycled glass not only improves the thermal and mechanical stability of mortar but also contributes to the sustainability of construction materials.

Name thesis:degree_name

Master of Science

Level thesis:degree_level

Masters

Discipline thesis:degree_discipline

Construction Management

Grantor

Texas State University

Year dc:date.issued

2025

Author dc:creator

• Salsabiyl, Anika

Advisor dc:contributor.advisor

• Espinoza, Wilson

Committee members dc:contributor.committeemember

• Moro, Carlos
• Torres, Anthony

• phase change material
• recycled crushed glass
• sustainable mortar

Language dc:language.iso

en

Handle dc:identifier.uri

https://hdl.handle.net/10877/22398

OAI identifier oai:identifier

oai:digital.library.txst.edu:10877/22398