Fatigue performance of fiber reinforced concrete for airport pavement

Objective To effectively address the fatigue damage of airport pavement caused by the combined action of aircraft load, environment and other factors, this study enhances the concrete through fiber reinforement, aiming to improve the durability of airport pavement structures and extend their service life. Method This study selected three high-performance fibers as reinforcing materials, i.e., modified polyester (FC), polyvinyl alcohol (PVA), and novel polyolefin (PP). The three-point bending fatigue tests with controlled stress mode were conducted. The fatigue response and failure characteristics of three fiber-reinforced concretes were compared and analyzed at multiple stress levels. The improvement effects of these fibers on concrete fatigue performance were investigated.P-S-N curve clusters and corresponding fatigue equations were established with survival probabilities of 0.50 and 0.95. The fatigue ultimate strength of materials under cyclic loading was quantitatively determined. Result Three fibers all effectively enhance the flexural tensile strength of concrete. FC fibers show the greatest improvement, reaching 23.25%; PVA fibers and PP fibers show improvements of 21.05% and 18.51% respectively. The fatigue life of fiber-reinforced concrete significantly increases at different stress levels. FC fibers demonstrate the most notable improvement. It can extend the fatigue life of concrete by 1 to 2 times. The fatigue life distribution of fiber-reinforced concrete follows two-parameter Weibull distribution. The effectiveness of three synthetic fibers for improving concrete fatigue resistance is ranked from large to small as FC, PVA, PP. Conclusion This study characterized the fatigue performance variation characteristics of fiber-reinforced concrete, offering the theoretical basis and data support for fatigue resistant design and long-term service performance prediction on high-durability airport pavement.