Balanced Mix Design and Performance Analysis of High-Modulus Asphalt Mixtures.

The objective of this study was to design mixtures that satisfy multiple performance criteria to build long-life pavement. A balanced mix design was employed to optimize AC-16, BBME-13, and EME-20 mixtures. The initial asphalt contents were determined using 4% air voids for the AC-16 mixture and the abundance coefficient K for BBME-13 and EME-20. Mixtures with two additional asphalt contents were also tested. A uniaxial penetration test, semi-circle bending test (to measure the flexibility index), and semi-circle bending test (to measure fracture energy) were used as performance tests. Then, a performance space diagram was created for a balanced analysis of the mixtures' high-, intermediate-, and low-temperature performance. Finally, fatigue performance was verified. The results show that BMD could be used to evaluate different asphalt mixtures. The 20# BBME-13 (5.1%, 5.4%, and 5.7%), 50# BBME-13 5.4%, and 20# AC-16 4.7% mixtures had well-balanced performances and are recommended. The BBME-13 and EME-20 mixtures had higher fatigue lives and lower sensitivity to stress than the AC-16 mixture. For the BBME-13 and AC-16 mixtures, reducing the asphalt grade significantly increased fatigue life and decreased the sensitivity to stress. At a low stress ratio, the 20# EME-20 mixture had the best fatigue performance, whereas at a high stress ratio, the 20# BBME-13 mixture had the best fatigue performance.