LAUSR

Abstract The effects of the reclaimed asphalt pavement (RAP) source and content on the dynamic modulus (E*) of hot mix asphalt concrete were characterized. Two parameters were proposed: the non-dimensional dynamic modulus-temperature index ( ∇ E T * ) and non-dimensional dynamic modulus-frequency index ( ∇ E fr * ). Parameter ∇ E fr * indicates the increase of relative E* per unit percent RAP from different sources during frequency and temperature sweeps, while ∇ E T * characterizes the reduction of relative E* per 1 °C temperature increase. An analysis of the results showed that ∇ E T * of RAP mixes were 6.80% to 12% higher than those of the control samples, indicating less temperature susceptibility. Furthermore, an analysis of ∇ E fr * trends showed temperature independency at higher temperature ranges. In addition, the results showed that the activation energy (AE) of the mixes was 1.51 MJ/mol/K to 9.86 MJ/mol/K higher than that of the control samples (without RAP), which depends on the RAP content and source. Moreover, E* linearly increases as AE increases. In conclusion, the increase of intermolecular forces owing to the higher AE in the blended binders increased the mix stiffness, which resulted in a higher E* in mixes containing RAP.