Investigation on the piezoresistive response of carbon fiber-graphite modified asphalt mixtures

Abstract

The correlation between the electrical properties of carbon fiber-graphite composite conductive asphalt mixes and their cracking damage can provide an early warning function for cracking. This study is devoted to exploring the force-electrical sensitivity of conductive concrete to find new solutions for asphalt pavement cracking warning. Firstly, a carbon fiber-graphite composite modified asphalt mixture was prepared; Secondly, the force-electrical sensitivity of the mixture was verified by direct and indirect tensile creep test. The tests showed that the resistivity and its cracking degree had a strong correlation. As the crack increases, so does the resistance. When the cracking reaches a certain level, the sudden change in resistance indicates that the mixture has been destroyed internally. Its resistivity and strain show a clear correlation before the mixture is broken. With the increase of strain, the resistivity gradually decreases. At the stage of large fluctuations in resistivity, it can be assumed that the mixture has reached the load carrying capacity limit, and at the stage of increasing resistivity abruptly, it can be judged that the mixture has undergone damaged and lost strength. Finally, the road performance was verified. A comparative study found that the high temperature, water stability and crack resistance are better than those of ordinary and graphite, and the fatigue performance is better than that of graphite. The research of the carbon fiber-graphite composite conductive asphalt concrete provides technical support for the application of the next crack warning function.