Optimization and characterization of composite modified asphalt with pyrolytic carbon black and chicken feather fiber

Asphalt is a vital construction material for roads, and its properties can be enhanced by modification. In this study, a composite modified asphalt was developed using pyrolytic carbon black (PCB) and chicken feather fiber (CFF). Box–Behnken design of response surface methodology was employed to optimize the preparation parameters, and the optimal parameters were determined to be a PCB dosage of 15% (weight ratio), a CFF dosage of 0.3% (weight ratio), and a chicken feather (CF) shear time of 8.2 min. A Dynamic Shear Rheometer (MCR302) was used to analyze the high-temperature rheological properties of the modified asphalt samples, and the results showed that the addition of PCB and CFF enhanced the high temperature performance and anti-aging performance of the asphalt. The rheological properties at high temperature increased progressively with the increase in CFF dosage. The Bending Beam Rheometer (BBR) test was conducted to evaluate the low-temperature rheological property of PCB/CFF composite modified asphalt, which was observed to decrease with the increase in CFF dosage. The microscopic properties and the chemical group of 15% PCB + 0.3% CFF with 8.2 min CF shear time composite modified asphalt (0.3%PC-MA) were analyzed using Fourier Transform Infrared spectrometer and Fluorescence Microscopy, and the results indicated that PCB and CFF were physically blended with asphalt without undergoing a chemical reaction, and they were well compatible with and evenly distributed in asphalt. Finally, the high- and low-temperature performances, as well as water stability, of the base asphalt (BA), 15% PCB dosage modified asphalt (P-MA), and 15% PCB dosage modified asphalt with % CFF dosage with a shear time of 8.2 min (PC-MA) were compared. The addition of CFF significantly enhanced the high-temperature and low-temperature performances, as well as water stability of P-MA mixtures. The aim of this study is to provide a laboratory test basis for the application of PCB/CFF composite modified asphalt.