Toward a Better Understanding of Benefits of Geosynthetics Embedded in Asphalt Pavements

Abstract

Reflective cracking is a serious issue in asphalt pavements. A common technique for preventive maintenance and rehabilitation is a thin asphalt concrete overlay; however, the application of a reinforcement can be a more suitable solution because such reinforcement can prevent or delay crack propagation. This paper presents research undertaken within a study of asphalt concrete overlays that included geosynthetics. A program of laboratory experiments and detailed analyses was conducted to gain insight into the effect of reinforcement in asphalt pavements by evaluating and quantifying the benefits of geosynthetic interlayers. Two test approaches were used. In the first approach, the specimens were analyzed by means of monotonic tests to investigate the bond at the interface and the contribution of the reinforcement to tensile strength. The results of the direct shear test indicated that the geosynthetic was able to guarantee a good bond at the interface, even at the end of the test. In the second approach, a nonconventional fatigue test was adopted to characterize the reinforced systems’ ability to resist fatigue cracking. X-ray tomography was performed to investigate the void structure of the beams tested under cyclic loadings. The research findings underline the benefits of geosynthetic interlayers embedded in asphalt pavements. The geosynthetics reduce the amplitude of the crack for high displacements and keep the pavement structure intact, even after moderate cracking has occurred in the overlay.