Suggested Citation:
Rahman, Mohammad, Angel Mateos, David Jones, Soroosh Amelian, Jeffrey Buscheck, Hanyu Deng, John T. Harvey (2026)

Medium-Term Oven Aging and Rapid Medium-Term Oven Aging for the Implementation of Balanced Mix Design

The selection of an appropriate long-term laboratory aging protocol for implementing balanced mix design remains a concern within the asphalt industry. In this study, two different loose mix aging protocols were applied: medium-term oven aging (MTOA) and rapid medium-term oven aging (RMTOA). MTOA protocol involved loose mix aging for 20 h at 100°C, whereas a temperature of 135°C was considered for RMTOA for a quick turnaround time. To determine the equivalent aging duration for RMTOA to produce similar aging effects as MTOA, six different asphalt concrete mixes containing reclaimed asphalt pavement (RAP) and recycling agents (RA) were oven aged at different aging temperatures and durations. Aging indices of the binders extracted from these mixes were applied to the Arrhenius equation to obtain the activation energy for different mix types. Despite the mixes differing in binder sources (four refineries) and RAP contents (up to 40%), the activation energy ranged narrowly between 68.1 kJ/mol to 72.9 kJ/mol. The use of Arrhenius activation energy suggested that around 3 h at 135°C laboratory aging (RMTOA) simulated the similar aging parameters of MTOA protocol (20 h at 100°C). In the second stage of this study, indirect tensile IDEAL cracking tolerance tests were performed on both RMTOA- and MTOA-aged specimens. Seven different AC mixes containing RAP and RA were considered to characterize the age-related cracking performance after MTOA and RMTOA. The ANOVA analysis indicated that two aging procedures (MTOA and RMTOA) are expected to produce similar effects on the IDEAL-CT results.