Micro-heterogeneous modification of an asphalt binder using a dimethylphenol and high-impact polystyrene solution: Fid-Bau Portal

Micro-heterogeneous modification of an asphalt binder using a dimethylphenol and high-impact polystyrene solution

Yoo, Pyeong Jun / Yun, Taeyoung

Highlights • We verified the oxidative condensation from dimethylphenol to polyphenylene oxide. • The modified asphalt exhibits an increase in |G^*|/sin(δ) of 2.14kPa at 82°C. • This indicates an improvement in its high-temperature rut resistance.

Abstract This study proposes a modified asphalt binder using a solution of high-impact polystyrene (HIPS) and 2,6-dimethylphenol (DMP). The oxidative polymerization of 2,6-dimethylphenol synthesizes a thermoplastic polymer (polyphenylene oxide, PPO) in the presence of copper, amines, and vanadium in the asphalt binder. The polymerization and existence of PPO were verified using X-ray diffraction and Fourier transform infrared (FTIR) spectroscopic analyses. The maximum crystallinity of the solution occurred after a mixing time of 2h with a homogenizer mixing energy of 3000rpm. The rheological properties of the DMP- and HIPS-modified binder are also investigated using a dynamic shear rheometer (DSR) and a bending beam rheometer (BBR). The modified asphalt binder exhibits an increase in |G ^*|/sin(δ) of 2.14kPa at 82°C without aging, which improves in the high-temperature rut resistance of the modified binder. The modification does not significantly affect the low-temperature crack resistance of the binder, considering that the m-value and stiffness at −12°C are 0.31 and 237MPa.