Influence of composite microencapsulated phase change material on the rheological property and applicability of asphalt

• Composites phase change asphalt binder was developed and characterized. • CMPCM enhances the high-temperature deformation resistance of asphalt. • CMPCM maintains a balanced viscoelastic property of the CMA system. • An optimal CMPCM content of 10–15% by mass of the asphalt was determined. Asphalt pavement cooling technology utilizing phase change materials offers significant long-term potential for mitigating the urban heat island effect, positioning it as a critical technology for advancing urban environmental protection and sustainable development. This study introduces a novel composite microencapsulated phase change material (CMPCM) synthesized from the organic monomer methyl methacrylate and SiO 2 through dehydration polycondensation, to prepare phase change modified asphalt (CMA). The stability of CMPCM in hot asphalt was verified through chemical and thermal tests. The impact of CMPCM on the rheological behavior of asphalt was thoroughly analyzed using dynamic shear rheometer, multiple stress creep recovery (MSCR), and low-temperature bending beam rheometer (BBR) tests, aiming to evaluate the feasibility of its application in cooling asphalt pavements. The results demonstrate that CMPCM remains stable in asphalt and exhibits excellent chemical compatibility with it. The melting enthalpy of CMPCM-containing asphalt reaches 21.88 J·g −1 , indicating strong temperature regulation potential. Dynamic viscoelastic analysis of CMA, using the Black diagram and 2S2P1D model, reveals that CMPCM increases the complex modulus of asphalt in the low-frequency region, maintaining a relatively stable viscoelastic state. MSCR test results show that, at lower stress levels, CMA exhibits excellent elastic recovery and low non-recoverable creep compliance between 40 and 50°C, highlighting CMPCM’s substantial enhancement of high-temperature deformation resistance. However, BBR results, based on the Burgers model, suggest that higher CMPCM content reduces the low-temperature cracking resistance of asphalt. When the CMPCM content is maintained between 10–15 %, CMA not only satisfies the low-temperature performance requirements for asphalt pavements but also improves high-temperature deformation resistance.