Investigating Low-Temperature Cracking Behavior of Fiber-Reinforced Asphalt Concrete Materials

The present work investigates low-temperature cracking performance of fiber-reinforced asphalt concrete (FRAC) materials. Different asphalt mixtures containing various amounts of fiber were explored. Disk-shaped compact tension (DC(T)), indirect tensile (ID(T)), and acoustic emission (AE) tests were conducted to evaluate cracking performance of FRAC materials. In addition, the AE test was utilized to investigate low-temperature fracture in fiber-modified asphalt binders. Results demonstrated that incorporating fibers improved low-temperature cracking behavior of asphalt mixtures by increasing the fracture energy by 4.3% and tensile strength by 5.1% per ounce of fiber added to the material. Moreover, it was observed that presence of fibers enhanced fracture softening behavior of FRAC mixtures. Asphalt binder results showed that fiber-modified binders consistently exhibited lower embrittlement temperatures indicating higher resistance against thermal cracking. The AE hit counts in both FRAC mixtures and asphalt binders significantly decreased at the average rate of 8.3 and 9.6% per ounce of fiber added to mixtures and asphalt binders, respectively. Finally, a cracking performance prediction model was developed for FRAC materials using the machine learning elastic-net regression approach.