Abstract

To mitigate high-temperature distress in asphalt pavements and enhance thermal regulation, flaked paraffin wax (FPW) was selected as the PCM and incorporated into asphalt. To prevent leakage, FPW was microencapsulated (FPW-MPCM). To boost thermal conductivity, FPW-MPCM was combined with expanded graphite (EG) via two methods: One method involves using EG as an adsorption carrier to prepare EG-adsorbed FPW phase change microcapsules (FPW-MPCM-EG); the other method uses EG as the core material to prepare FPW/EG graphite phase change microcapsules (FPW/EG-MPCM). These four PCMs were added to asphalt at 3 %, 6 %, 9 %, and 12 % (wt.%) to prepare phase-change asphalt (PCMA) and mixtures (PCAM). The high and low temperature PG grading of PCMA was determined using temperature-sweep and bending beam rheometer tests. At a 6 % dosage, the high- and low-temperature performance was optimal. On this basis, the thermophysical properties of PCAM at a 6 % dosage were measured. Its pavement performance was validated, and its temperature-regulation performance was evaluated, followed by a correlation analysis. Results suggest that a 6 % PCMA content provides the best balance of properties under both high and low temperatures. At 12 % dosage the thermal conductivity of FPW/EG-MPCM increased by 49.83 %. PCMs delayed the temperature rise and reduced the peak temperature. The 6 % FPW sample was 4.1 °C lower than base asphalt mixture. At 6 % dosage the dynamic modulus of FPW-MPCM-EG and FPW/EG-MPCM increased by 9.8 % and 9.3 %, respectively, relative to F6, indicating improved high-temperature rutting resistance. In summary, FPW-based thermally enhanced composite PCMs effectively increased the thermal conductivity of PCAM, providing important guidance for designing temperature-regulated asphalt pavements with efficient thermal response.

Department(s)

Civil, Architectural and Environmental Engineering

Publication Status

Full Text Access

Comments

National Key Research and Development Program of China, Grant 2023YFB2604600

Keywords and Phrases

Asphalt mixture; Phase change materials; Road performance; Thermal properties; Thermally enhanced

International Standard Serial Number (ISSN)

0950-0618

Document Type

Article - Journal

Document Version

Citation

File Type

text

Language(s)

English

Rights

© 2026 Elsevier, All rights reserved.

Publication Date

28 Mar 2026

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