Fatigue Properties of Cold-Recycled Emulsified Asphalt Mixtures Fabricated by Different Compaction Methods

This paper focuses on investigating the fatigue properties of cold-recycled emulsified asphalt mixtures (CEAMs) designed via two different compaction methods. First, two different CEAM compaction procedures were investigated and evaluated, including the modified Marshall compaction method (MMCM) and the vertical vibration testing method (VVTM). Indirect tensile fatigue tests were then performed to research the fatigue lives of CEAMs fabricated via the two methods. Finally, a Weibull distribution was applied to analyze the fatigue test results, and the fatigue equation was constructed. The results indicated that the average mechanical strength ratio between the CEAM samples produced by VVTM and the field core samples was >92%, whereas the average ratio of the specimens shaped by the MMCM was <65%. Compared with MMCM-molded CEAMs, VVTM-fabricated CEAMs showed decreased optimal moisture and emulsified asphalt contents by 11% and 9%, respectively, but exhibited improved moisture stability, anti-cracking performance, and anti-rutting performance by 4%, 12%, and 35%, respectively. The fatigue equations established on the basis of the Weibull distribution could effectively assess the fatigue life of CEAMs. The VVTM-manufactured CEAMs showed good resistance of stress change sensitivity and fatigue failure under different stress ratios. The VVTM-compacted CEAMs demonstrated increased fatigue life by 36% at a stress ratio of 0.45 and by 325% at a repeated load of 0.27 MPa compared with the MMCM-fabricated CEAMs.