Gradation Design and Effectiveness Analyses of High Modulus Asphalt Concrete

In order to improve the performance of heavy-traffic asphalt pavement, high modulus asphalt concrete (HMAC) was designed and evaluated. During the design of HMAC, the key sieves of 0.075, 2.36, 4.75, and 9.5 mm were controlled in gradation design. In the asphalt-aggregates determination, the abundance coefficient (K) was employed. Subsequently, the HMAC with three gradations, numbering 1#, 2#, and 3# HMAC-20, was designed and further evaluated by laboratory tests, including wheel tracking test, three-point bending test, immersion Marshall test, and freeze-thaw splitting test. Analyzed results show that HMAC with gradation of 2# HMAC-20 is associated with a higher effectiveness, especially in high-temperature stability, low-temperature performance, and fatigue performance. It indicates that the dense-grade asphalt pavement with hardened asphalt provides higher modulus. Moreover, the moisture proof is necessary to improve the moisture susceptibility.