Thermoregulation Performance and Mechanical Properties of Phase Change Asphalt Mortars

Abstract

This study investigated the effects of a diatomite/tetradecane composite shaped phase change material (CSPCM) on the mechanical properties and thermoregulation performance of styrene-butadiene-styrene (SBS)- and styrene-butadiene-styrene/crumb rubber (SBS/CR)-modified asphalt binders. The heat transfer and latent heat characteristics of phase change asphalt mortars (PCAMs) were analyzed using a thermal constant analyzer and differential scanning calorimeter. Furthermore, a thermoregulation test was devised to confirm the temperature-regulating characteristics of PCAMs. The rheological properties of PCAMs were analyzed using the dynamic mechanical analysis (DMA) method, and low-temperature fracture characteristics were evaluated using the single edge notched beam (SENB) test. The results indicated that the incorporation of CSPCM decreased the thermal conductivity and thermal diffusivity of SBS- and SBS/CR-modified asphalt binders but increased their specific heat capacity. CSPCM can be stably present in modified asphalt and still have good phase change properties in the phase change temperature range, as well as the temperature regulation effect of PCAMs is excellent. The melting enthalpy for the PCAMs was as high as 73.29 J/g. Compared to the modified asphalts, the heating time of the PCAMs increased by up to 34.1% as the dosage of CSPCM gradually increased. The incorporation of CSPCM enhanced the viscous components of modified asphalt binders, improved intermediate-temperature fatigue resistance and low-temperature fracture resistance, and reduced high-temperature permanent deformation resistance.