Analysis of Compressive Characteristics of Asphalt Mixture under Freeze-Thaw Cycles in Cold Plateau Regions

Abstract

Low average temperature, large temperature difference, and continual freeze-thaw (F-T) cycles are the typical climatic characteristics of cold plateau regions. F-T cycles and the asphalt-aggregate ratio of an asphalt mixture have been analyzed using a uniaxial compressive test under F-T cycles. The results show that the compressive strength and resilient modulus decrease with an increase in the number of F-T cycles. The mixture performance declines sharply in the initial F-T cycles and gradually gentle after 8–10 F-T cycles. Further, the asphalt-aggregate ratio has a significant influence on the compressive characteristics of the mixture under F-T cycles: a lower asphalt-aggregate ratio leads to a better compressive performance than a higher asphalt-aggregate ratio. A higher asphalt-aggregate ratio leads to a small loss ratio of compressive performance under F-T cycles. The results also reveal that F-T cycles obvious impact on the compressive properties of the mixture and that the use of asphalt concrete (AC) -13 with an optimum asphalt content (5.5%) or more can improve the low-temperature compressive performance of the mixture under F-T cycles.