Evaluation of compactability of asphalt mixture utilizing asphalt vibratory compactor

Compaction is a crucial topic for asphalt mixture in that the success of mix design greatly depends on the compaction method being used, and the asphalt pavement achieves the required density also through sufficient compaction efforts in the field. Therefore, understanding the compaction characteristics of asphalt mixture is necessary. In this study, the compactability of asphalt mixture was evaluated utilizing lab asphalt vibratory compactor and three types of mixtures, and an accelerometer was utilized to monitor the vibration properties of vibrator-mixture system. Stiffness measurement values derived from Intelligent Compaction were employed to characterize and identify the compaction stages of asphalt mixture. Results indicated that the vibratory compaction of asphalt mixture can be classified into three stages for all the mixtures, and stiffness parameters can differentiate the compactability of asphalt mixtures. Linear relationships were found between air voids and stiffness parameters with most R square values greater than 0.5 for three mixtures. The influences of compaction temperature (120 °C vs. 140 °C) and underlying layer on the compactability of asphalt mixture were further discussed.