Evaluation of Rutting and Fatigue Behavior of Modified Asphalt Binders with Nanocomposite Phase Change Materials

In this study, the influence of modifying asphalt binder with TiO2, Al2O3 as a phase change material, and multiwalled carbon nanotube (MWCNT) as an accessory of the nanocomposite PCMs, were investigated on rutting and fatigue behavior of asphalt binders. First, rotating thin-film oven (RTFO) and pressurized aging vessel (PAV) tests were conducted. Then, some analyses and tests, including scanning electron microscopy (SEM), differential scanning calorimetry (DSC), rotational viscosity (RV), multiple stress creep recovery (MSCR), linear amplitude sweep (LAS), and loaded-wheel tracking (LWT), were carried out. RV and DSR tests showed that the modified asphalt binders had more viscosity and aging resistance compared to pure asphalt binders, especially the ones including nanocomposite structure of PCMs role of TiO2 alongside MWCNT. Fatigue life in the LAS test for TiO2-MWCNT modified was more than 1.7 times the PP value (Control sample). MSCR test results indicated that the best improvement according to J(nr) values was for TiO2-MWCNT-modified asphalt binder, especially at higher temperatures because of their high specific heat capacity (C-p) as a PCM material. In addition, TiO2-MWCNT-modified asphalt binder almost met the Jnr limitation for much heavy traffic and heavy traffic loading at 64 & DEG;C and 70 & DEG;C, respectively. In general, combinations with the nanocomposite structure of PCMs were the best ones. In summary, aging index (AI) and G* x sin (& delta;) did not accurately confirm each other, while G* x sin (& delta;) and fatigue life from the LAS test were accurately correlated.