Evaluation of performance of asphalt binders containing capric acid based form-stable phase change materials

Phase Change Materials (PCMs) are functional and promising materials due to their tailored properties designed for various applications. Considering the wide range of applications, the use of PCMs with asphalt binders has also attracted attention in recent years. This study focuses on the effect of the adding fatty acid-based shape-stabilized composite PCM prepared by solvent-assisted impregnation to asphalt binders. For this purpose, a favorable material, capric acid (CA) was used. In addition, pumice (PUM), a natural and abundant material also known as lightweight aggregate, was preferred as the support material. The features of the prepared composite PCM was named CA-PUM, were examined by conducting the well-known methods, namely Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM) and differential scanning calorimetry (DSC) analyses. The latent heat of melting of CA-PUM was found to be as 46.58 J/g with the incorporation ratio as 34.96 wt%, while the melting peak temperature was determined as 30.93°C. The performance of modified asphalt binders with 0.5%-2.0% (wt/wt) CA-PUM were evaluated by penetration, softening point, rotational viscosity (RV), dynamic shear rheometer (DSR), rolling thin film oven (RTFO) and pressure aging vessel (PAV) tests. Based on the performance test results, the modified asphalt binder included 1.0 wt% CA-PUM demonstrated distinguishable properties in terms of increased resistance to deformations, the highest softening point and viscosity values besides to highest rutting performance.