ABSTRACT
The incorporation of geosynthetic interlayers during the asphalt overlay construction has proven successful in mitigating the reflective cracking and enhancing the pavement structural capacity. However, milling an asphalt layer reinforced with geosynthetic interlayer is a huge concern, since there is a possibility of geosynthetic interlayers compromising the reclaimed asphalt pavement (RAP) quality and characteristics. On the other hand, inclusion of RAP into the hot mix asphalt (HMA) is a common practice. Hence, it is important to understand the characteristics of RAP collected from geosynthetic-reinforced asphalt layers (referred herein as GRAP) and their influence on the performance of asphalt mixtures. The objective of this study is to understand the characteristics of GRAP and subsequently, investigate the performance of asphalt mixtures with 15% and 30% GRAP contents. Additionally, the performance of asphalt mixtures with 15% and 30% RAP contents, and 100% virgin aggregates (referred as control mixture) was evaluated for comparison with that of asphalt mixtures combining GRAP. The characterization of GRAP and RAP included particle size gradation and binder extraction tests, while the performance evaluation of the asphalt mixtures included indirect tensile strength, and moisture susceptibility tests. Comparison of binder extraction test results revealed that the GRAP samples had binder content slightly higher than that of the RAP samples. While the comparison of indirect tensile strength and moisture susceptibility test results indicated the performance of asphalt mixtures with GRAP similar to that with RAP, where both mixtures outperformed the asphalt mixtures made solely of virgin aggregates. This indicates the potential of incorporating GRAP and RAP up to 30% into the asphalt mixtures without compromising the performance of asphalt mixtures.
