Characterization of effects of reclaimed asphalt pavement (RAP) source and content on dynamic modulus of hot mix asphalt concrete

摘要

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 (del E-T*) and non-dimensional dynamic modulus-frequency index (del E-fr*). Parameter del E-fr* indicates the increase of relative E* per unit percent RAP from different sources during frequency and temperature sweeps, while del E-T* characterizes the reduction of relative E* per 1 degrees C temperature increase. An analysis of the results showed that del 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 del 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. (C) 2019 Elsevier Ltd. All rights reserved.