Evaluation of the dynamic modulus of asphalt mixture incorporating reclaimed asphalt pavement

This paper presents the effects of temperature and loading frequency on the dynamic modulus and phase angle of asphalt mixtures incorporating reclaimed asphalt pavement (RAP) using the asphalt mixture performance tester. Milling waste from Damansara-Puchong Expressway is incorporated in asphalt mixtures in proportions of 0%, 10%, 20%, 30% and 40%. The asphalt mixtures are tested for dynamic modulus at three temperatures (20, 40, 50°C) and six loading frequencies (0.1, 0.5, 1, 5, 10 and 25 Hz). At constant temperature, the dynamic modulus increased as the loading frequency and RAP content increased. For a given frequency, the dynamic modulus decreased while the phase angle increased as the temperature increased. From statistical analysis, test temperature and frequency have significant effects with high effect size on the measured dynamic modulus and phase angle. The interaction effect of frequency and RAP give the highest effect size among the interaction effects in the dynamic modulus test. The results also indicated that the highest performance in terms of rutting and fatigue factors can be attained when the frequency of cumulative traffic loading was from 15 to 20 Hz.