ABSTRACT

Published studies generally demonstrate positive benefits from using Mechanically Fibre-Reinforced Asphalt Concrete (M-FRAC). However, improvements vary with the particular asphalt mixture used in previous studies. The specific objectives of this study were to evaluate the mechanical properties of various asphalt mix designs reinforced with and without aramid fibres, to identify and quantify the key factors in the composition of asphalt mixtures that facilitate to the reinforcement mechanism of fibres, and finally associate the effect of asphalt mixture constituents on laboratory modulus, rutting and fatigue performance of M-FRAC. A total of seven different asphalt mix designs from across the United States were used in this study. For each mixture a non-fibre-reinforced variant and an M-FRAC variant were created and compared. Results showed that while overall fibres can improve the mechanical performance of asphalt mixtures, the degree of improvement varies from one mix to another. Further analysis and interpretation of the mixtures constituents revealed that there is a strong link between fibre reinforcement efficiency and composition of the asphalt mixtures. In particular, it was found that the effective binder content and gradation of the asphalt mixtures are good indicators of the likely performance benefit of M-FRAC with respect to rutting and fatigue cracking, respectively.

摘要

已发表的研究普遍证明了使用机械纤维增强沥青混凝土 (M-FRAC) 的积极益处。然而，改进因先前研究中使用的特定沥青混合物而异。本研究的具体目标是评估使用和不使用芳纶纤维增强的各种沥青混合料设计的力学性能，识别和量化沥青混合料组成中促进纤维增强机制的关键因素，并最终关联沥青混合料成分对 M-FRAC 实验室模量、车辙和疲劳性能的影响。本研究共使用了来自美国各地的七种不同的沥青混合料设计。对于每种混合物，创建并比较了非纤维增强变体和 M-FRAC 变体。结果表明，虽然整体纤维可以改善沥青混合料的机械性能，但改善程度因混合料而异。对混合物成分的进一步分析和解释表明，纤维增强效率与沥青混合物的成分之间存在密切联系。特别是，发现沥青混合物的有效粘合剂含量和级配是 M-FRAC 在车辙和疲劳开裂方面可能的性能优势的良好指标。对混合物成分的进一步分析和解释表明，纤维增强效率与沥青混合物的成分之间存在密切联系。特别是，发现沥青混合物的有效粘合剂含量和级配是 M-FRAC 在车辙和疲劳开裂方面可能的性能优势的良好指标。对混合物成分的进一步分析和解释表明，纤维增强效率与沥青混合物的成分之间存在密切联系。特别是，发现沥青混合物的有效粘合剂含量和级配是 M-FRAC 在车辙和疲劳开裂方面可能的性能优势的良好指标。