Investigations on Reflective Crack Mitigation in Geosynthetic-reinforced Asphalt

Abstract: Geosynthetic interlayers have proven to improve the fatigue life of asphalt layers by resisting reflective cracks. However, the complexity of crack propagation modes and the mechanisms associated with different geosynthetic interlayers is complex, which necessitate further studies to develop design methodologies involving geosynthetic-reinforced asphalt. In this regard, this study aims to evaluate the performance of asphalt slabs reinforced with geosynthetic interlayers by using cyclic four-point bending tests combined with Digital Image Correlation (DIC). Specifically, with an objective to better understand the failure modes and the mechanisms by which geosynthetic reinforcement minimize reflective cracking and enhance the pavement performance. Geosynthetic-reinforced and unreinforced specimens were extracted from an experimental section constructed at Salvador International Airport, Bahia and prepared for the testing program. The results demonstrated that the DIC technique is effective in determining the tensile strains developed at the crack-tip during testing. Thus, providing a better understanding of the reinforcement mechanisms involved. Additionally, DIC analysis provided clear insights into how geosynthetic interlayer retards crack propagation in asphalt layers. The presence of the geosynthetic interlayer between asphalt layers increased the fatigue life by about 13-fold compared to the unreinforced asphalt layers. Overall, this study highlights the effectiveness of geosynthetic interlayers in resisting the reflective crack propagation in asphalt overlays. The DIC analysis offered detailed insights into strain distribution and crack-tip behavior, underscoring the substantial benefits of geosynthetic interlayers in strengthening the structural resilience of asphalt layers. The findings emphasize that the shear bond at the interface was maintained, demonstrating the critical importance of both interface bonding and reinforcement properties in extending pavement service life under repetitive loading.