Investigation on chemically modified carbon black in enhancing asphalt performance

Asphalt is still regarded as the most common raw material for road paving. In the pursuit of more long-term sustainability and the creation of durable and resilient pavements, researchers are diligently exploring high-quality asphalt. The objective of this study was to delve into the behavior of carbon black (CB)-modified asphalt, through conducting the conventional tests. The determination of the optimal pyrolysis temperature for CB involved assessing productivity, ash content, oil absorption value, iodine absorption value, and scanning electron microscopy (SEM). The modification was undertaken to generate modified carbon black (MCB), involving nitric acid oxidation and hydroxymethylation. The MCB was confirmed through total acidity (T), carboxyl and lactone groups (P), and hydroxyl groups (Q), complemented by SEM, Fourier transform infrared spectroscopy (FTIR), and Brunauer-Emmett-Teller (BET) characterization. The optimal MCB dosage determination of 15% was accomplished by employing three index tests. Fluorescence microscopy was employed to illustrate the dispersion compatibility between MCB and asphalt. To assess the high-temperature performance and resistance to aging of CB and MCB modified asphalt, dynamic shear rheometer (DSR) temperature scanning was employed. The findings revealed that MCB significantly enhanced the temperature sensitivity, viscosity, rheological properties, and high-temperature characteristics of the modified asphalt. Moreover, the incorporation of CB and MCB exhibited improved anti-aging behavior in the asphalt.