Key Laboratory of Special Area Highway Engineering of the Ministry of Education, Chang'an University, Xi'an 710064, Shaanxi, China.
School of Materials Science and Engineering, Chang'an University, Xi'an 710064, Shaanxi, China.
Sci Total Environ. 2022 Jan 15;804:150194. doi: 10.1016/j.scitotenv.2021.150194. Epub 2021 Sep 9.
Biochar has been utilized as a renewable biomass resource to develop sustainable and eco-friendly pavements. This study focuses on the influence of biochar as an asphalt modifier on the improvement of high-temperature performance of asphalt. A series of tests were performed to comprehensively evaluate the high-temperature performance of the biochar modified binder. The interaction mechanism between the biochar and the binder was explored using scanning electron microscopy and Fourier-transform infrared spectroscopy (FTIR). The results indicated that the complex modulus and penetration of the biochar-modified asphalt binder could be increased by up to 35% and 36.5%, respectively, compared with those in case of the matrix asphalt, thereby improving the deformation resistance. In addition, the observed increase in the complex modulus, rutting factor, and viscosity-temperature index contributed to the improvement of temperature sensitivity and anti-rutting properties. These relationships are attributed to the fact that biochar has a fibrous porous structure and forms a skeleton and stiffening zone in the binder. Although biochar has a negative effect on the low-temperature properties of the binder, this can be alleviated by controlling the biochar content. Moreover, the FTIR results showed that no new chemical functional groups appeared after the incorporation of biochar into the binder. The internal chemical environment of the biochar-modified asphalt binder was different from that of the matrix asphalt. In conclusion, biochar is feasible as a modifier for binders owing to its high-temperature properties.
生物炭已被用作可再生生物质资源，用于开发可持续和环保的路面。本研究关注生物炭作为沥青改性剂对改善沥青高温性能的影响。进行了一系列测试，以综合评估生物炭改性胶结料的高温性能。利用扫描电子显微镜和傅里叶变换红外光谱（FTIR）探讨了生物炭与胶结料之间的相互作用机制。结果表明，与基质沥青相比，生物炭改性沥青胶结料的复数模量和针入度可分别提高 35%和 36.5%，从而提高了变形阻力。此外，观察到的复数模量、车辙因子和粘度-温度指数的增加有助于改善温度敏感性和抗车辙性能。这些关系归因于生物炭具有纤维状多孔结构，并在胶结料中形成骨架和增强区。尽管生物炭对胶结料的低温性能有负面影响，但通过控制生物炭含量可以减轻这种影响。此外，FTIR 结果表明，生物炭掺入胶结料后没有出现新的化学官能团。生物炭改性沥青胶结料的内部化学环境与基质沥青不同。总之，由于其高温性能，生物炭作为胶结料的改性剂是可行的。
