Performance assessment of microencapsulated phase change materials with low to high thermoregulation range in asphalt binder

This study aims to assess the impact of microencapsulated phase change materials (MPCMs) on thermoregulation effect and binders' performance. Accordingly, three MPCMs with melting points 6 degrees C, 28 degrees C, and 37 degrees C were blended with PG 58-28 and PG 64-22 binders at dosages of 5%-20% by binder weight. Subsequently, laboratory experiments were conducted to examine impact on thermoregulation and rheological parameters including enthalpy change, complex modulus, Glover-Rowe parameter, creep stiffness, creep slope, fatigue, and rut factors. The findings showed that increasing MPCMs' dosage in both control binders led to increased enthalpy change, indicating successful thermoregulation and capsules' survival during blending. Rheological investigation depicted increasing complex modulus, creep stiffness and Glover-Rowe parameter in modified binders compared to control binders regardless of MPCMs' thermoregulation range. However, Dynamic shear rheometer and Bending beam rheometer may not adequately capture their thermoregulation impact under steady-state conditions, necessitating use of temperature sweep test to validate influence on complex modulus and phase angle due to their thermoregulation capability. Temperature sweep test showed that within thermoregulation range, MPCMs with melting points 6 degrees C and 28 degrees C showed comparable fatigue resistance to respective control binders up to 10% dosage. Meanwhile, around melting point, MPCM with 37 degrees C melting point enhanced rutting resistance.