Carbon Fiber Powder in Sustainable Asphalt Pavements: Improving Microwave Self-Healing Capacity and Low-Temperature Performance

Enhancing the microwave self-healing capability of asphalt mixtures is a crucial step in achieving energy-efficient and emissions-reducing road maintenance. Along these lines, carbon fiber powder (CFP), which is a high-performance microwave absorber, was used to partially replace limestone powder (LP) as filler in asphalt mixture to improve microwave self-healing capacity and low-temperature cracking resistance. The properties of CFP-based asphalt mastics and asphalt mixtures were studied from aspects of physical and chemical properties of fillers, rheological properties of asphalt mastics, low-temperature performance of asphalt mixtures, microwave heating and self-healing capacities of asphalt mixtures. Additionally, an analysis of the cost and environmental benefits of microwave self-healing roads was conducted. The results indicate that the addition of CFP can increase the stiffness and elasticity of asphalt mastics and can significantly improve the low-temperature cracking resistance of asphalt mixtures. The study also found that the microwave heating rate of CFP is 19.05 times than that of LP, which is linked to the stable and outstanding dielectric loss characteristics of CFP. Compared with LP-based asphalt mixtures, the CFP-based asphalt mixtures exhibit stronger microwave self-healing capacities. The CFP replacement rate for showing the best microwave self-healing capacity is 25%. At this replacement rate, the asphalt mixture also exhibits the best low-temperature cracking resistance performance. In addition, the results show that the CFP-based microwave self-healing road exhibits lower costs over its service life and reduces carbon emissions during maintenance. Overall, the CFP-based asphalt mixtures show great potential for achieving economic and environmental sustainability in road infrastructure.