Back-calculation method for determining the maximum RAP content in Stone Matrix Asphalt mixtures with good fatigue performance based on asphalt mortar tests

• Performing Dynamic Shear Rheometer tests on mortars containing RAP.
• Back-calculating the rheological properties of bituminous blends from mortars.
• Determining the maximum amount of RAP in SMA mixture in terms of fatigue resistance.
• Validating the procedure on fatigue using Linear Amplitude Sweep tests.

This paper presents a simple method to determine the amount of Reclaimed Asphalt Pavement (RAP) that can be added to Stone Matrix Asphalt (SMA) mixtures without compromising the fatigue resistance. Dynamic Shear Rheometer tests (DSR) on binder and mortars composed with fine RAP particles, called Selected Recycled Asphalt Pavement (SRAP) are used together with the Nielsen model to back-calculate the norm of the complex modulus of the bituminous blend of fresh and RAP binder. Fatigue properties are derived from parameter G*sinδ and Linear Amplitude Sweep tests. The analysis indicates that a limiting SRAP binder content of 23% can be included in SMA mixtures with satisfactory fatigue performance.