Long-term performance of fiber-grid-reinforced asphalt overlay pavements: A case study of Korean national highways

The objective of this study was to verify the effect of fiber grid reinforcement on the long-term performance of asphalt overlay pavements by performing field investigation, laboratory test, and finite element analysis. Crack, rutting, roughness, and other miscellaneous distresses of fiber-grid-reinforced overlay sections and ordinary overlay sections were compared. Pavement conditions of fiber grid overlay sections before and after the overlay were also compared. Cores were obtained from the fiber-grid-reinforced and ordinary sections to measure bonding shear strength between the intermediate and overlay layers. Fracture energy, displacement after yield, and shear stiffness of the cores were also obtained by analyzing the test results. Finite element analysis was performed by using the test results to validate the effect of the fiber grid reinforcement on the long-term performance of asphalt overlay pavements. Rutting and fatigue cracking were predicted for three cases: 1) fiber grid was not used; 2) glass fiber grid was used; and 3) carbon fiber grid was used. The cracking ratio of fiber-grid-reinforced sections was much smaller than that of ordinary sections. The results of field investigation, laboratory test, and finite element analysis showed that the fiber grid reinforcement improved the long-term performance of asphalt overlay pavements.