ABSTRACT

Fibre is one of the most popular additives in hot mix asphalt (HMA). However, there are few research studies about the application of fibres in cold recycled mixture with asphalt emulsion. In this study, five popular fibres are introduced to the emulsion recycled mixture, including polyester fibre, polypropylene (PP) fibre, polyacrylonitrile (PAN) fibre, lignin fibre, and basalt fibre. The optimum pre-mixing water (OPW) content, optimum emulsion content (OEC) and optimum fibre content of recycled mixtures reinforced by fibres are determined. The indirect tensile strength (ITS), moisture susceptibility, bending cracking at low temperature, rutting and fatigue life of mixtures with these fibres are investigated. The test results indicate that the OPW and OEC of recycled mixture are influenced by types and contents of fibres. Although different fibres lead to obviously different ITS values, the optimum content for each fibre is near 0.3% by weight of RAP. All five fibres improve the performance properties of the emulsion recycled mixture. The improved percentages depend on the type of fibres. Polyester fibre has higher improvement on fatigue life than the other fibres. Therefore, polyester fibre is recommended as the most effective fibre to improve the emulsion recycled mixture.

摘要

纤维是热拌沥青 (HMA) 中最受欢迎的添加剂之一。然而，关于纤维在沥青乳液冷再生混合料中的应用研究较少。在这项研究中，五种流行的纤维被引入到乳液回收混合物中，包括聚酯纤维、聚丙烯 (PP) 纤维、聚丙烯腈 (PAN) 纤维、木质素纤维和玄武岩纤维。确定了纤维增强的再生混合物的最佳预混水 (OPW) 含量、最佳乳液含量 (OEC) 和最佳纤维含量。研究了这些纤维混合物的间接拉伸强度 (ITS)、湿气敏感性、低温弯曲开裂、车辙和疲劳寿命。测试结果表明，再生混合物的OPW和OEC受纤维类型和含量的影响。虽然不同的纤维导致 ITS 值明显不同，但每种纤维的最佳含量接近 RAP 重量的 0.3%。所有五种纤维都改善了乳液回收混合物的性能。提高的百分比取决于纤维的类型。与其他纤维相比，涤纶纤维对疲劳寿命的改善更高。因此，聚酯纤维被推荐为改善乳液回收混合物最有效的纤维。