Evaluating the Impact of Microencapsulated Phase Change Material on Low Temperature Cracking Resistance of Asphalt Binder

This study aims to assess the impact of microencapsulated phase change material (MPCM) on the low-temperature cracking of asphalt binders. To achieve this objective, MPCM6D with melting point of 6°C was selected. This MPCM was introduced into PG 64-22 binder at varying dosages (0%, 5%, 10%, and 20% by binder weight) using a low-shear mixer. Subsequently, the laboratory tests were conducted on prepared binders to evaluate the influence of MPCM on thermoregulation, encompassing parameters like enthalpy change, low temperature properties (creep stiffness and stress relaxation), and complex shear modulus change rate of binders. The results of the study revealed a direct correlation between the dosage of MPCM and the observed enthalpy changes. Moreover, matching of measured enthalpies with the expected values confirmed effective thermoregulation achieved during blending process, demonstrating survivability of capsules. Additionally, analysis using bending beam rheometer results indicated increase in creep stiffness and slight reduction in creep rate, depicting decrease in low-temperature cracking resistance, for MPCM modified binders. Further, it was observed from temperature sweep results that the MPCM6D exhibited the ability to enhance low-temperature cracking within the thermoregulation range. In conclusion, this study recommends exploring MPCMs with broader thermoregulation ranges or combinations of MPCM to extend their performance across wider spectrum of temperatures.