Research on the Pavement Performance of Fiber-Reinforced High Modulus Asphalt Concrete

Under high temperature and heavy load conditions, asphalt pavements are prone to rutting and other distress, which severely affect the service life of the road. High modulus asphalt concrete has significant advantages in addressing rutting issues in asphalt pavements. However, its low-temperature performance is often poor, especially in regions with hot summers, cold winters, and large diurnal temperature variations, which limits the application of this technology. Based on this, the study introduces three types of fibers: basalt fiber, polyester fiber, and lignin fiber as reinforcing materials to improve the performance of high modulus asphalt concrete. The effects of these fibers on the pavement performance of high modulus asphalt concrete are systematically evaluated through rutting tests, low-temperature bending tests, immersion Marshall tests, freeze–thaw splitting tests, fatigue tests, and dynamic modulus tests. The test results show that as the fiber content increases, the effect of the fibers on the high-temperature, low-temperature, and fatigue performance of high modulus asphalt concrete initially improves and then decreases. The impact on water stability is not significant, while the dynamic modulus performance decreases. Fibers can significantly improve the low-temperature performance of the mixture. Among them, basalt fiber shows the greatest improvement in high-temperature and fatigue performance, while polyester fiber provides the best improvement in low-temperature performance. The improvement effect of lignin fiber is not as pronounced as that of the first two fibers. All types of fibers have an adverse effect on the dynamic modulus of the mixture. Taking all factors into consideration, the recommended fiber contents for basalt fiber, polyester fiber, and lignin fiber are 0.4%, 0.3%, and 0.3%, respectively, as these levels exhibited the best overall performance among the discrete dosages investigated in this study. Based on the experimental results, and within the selected dosage range, a performance evaluation system for fiber-reinforced high modulus asphalt concrete is established.