Xia Chaoming, Wu Chaofan, Liu Kefei, Jiang Kang
Department of Road and Bridge Engineering, School of Civil Engineering, Central South University of Forestry & Technology, Changsha 410004, China.
Hunan Provincial Engineering Research Center for Construction Solid Wastes Recycling, Changsha 410205, China.
Materials (Basel). 2021 Mar 28;14(7):1667. doi: 10.3390/ma14071667.
To evaluate the durability of bamboo fiber asphalt mixture using four gradation schemes, the durability of the bamboo fiber asphalt mixture is studied considering three aspects: ageing durability, freeze-thaw cycle durability and fatigue durability through the Marshall test, indoor ageing test, uniaxial compression test, low-temperature bending test, immersion Marshall test, freeze-thaw splitting test and four-point bending fatigue test. Nonfiber asphalt mixture and lignin fiber asphalt mixture were used as control groups. The results show that the addition of plant fiber can effectively improve the durability of asphalt mixture. Bamboo fiber modified asphalt mastic has good ductility and adhesion due to its rough surface and good oil absorption performance. Bamboo fiber asphalt mixture has better and more stable low-temperature ageing durability and moisture ageing durability than lignin fiber asphalt mixture, but its mechanical property is weaker than the latter. The improvement effect of the two fibers on the freeze-thaw cycle durability of asphalt mixture is basically the same. Bamboo fiber can improve the flexibility of the mixture and delay the development of cracks so that the mixture has good fatigue durability. The smaller the void ratio, the thicker the asphalt film, and the denser the structure of the mixture, the better the durability. The durability of the stone mastic asphalt (SMA) gradation mixture is better than that of asphalt concrete (AC) gradation. The material composition and aggregate gradation of plant fiber asphalt mixture have a great influence on its durability. In the future, it is necessary to establish a multiparameter comprehensive evaluation index system among fiber type and properties, mixture gradation and durability so as to realize the directional regulation of the durability of different fiber asphalt mixtures. Bamboo fiber is a reliable substitute for lignin fiber, and further research on improving its surface properties and dispersion uniformity can be carried out in the future.
为采用四种级配方案评估竹纤维沥青混合料的耐久性，通过马歇尔试验、室内老化试验、单轴压缩试验、低温弯曲试验、浸水马歇尔试验、冻融劈裂试验和四点弯曲疲劳试验，从老化耐久性、冻融循环耐久性和疲劳耐久性三个方面研究了竹纤维沥青混合料的耐久性。以无纤维沥青混合料和木质素纤维沥青混合料作为对照组。结果表明，植物纤维的加入能有效提高沥青混合料的耐久性。竹纤维改性沥青玛蹄脂因其表面粗糙且吸油性能良好而具有较好的延性和黏附性。竹纤维沥青混合料比木质素纤维沥青混合料具有更好且更稳定的低温老化耐久性和水老化耐久性，但其力学性能比后者弱。两种纤维对沥青混合料冻融循环耐久性的改善效果基本相同。竹纤维能提高混合料的柔韧性并延缓裂缝发展，从而使混合料具有良好的疲劳耐久性。空隙率越小、沥青膜越厚、混合料结构越密实，耐久性越好。沥青马蹄脂碎石（SMA）级配混合料的耐久性优于沥青混凝土（AC）级配。植物纤维沥青混合料的材料组成和集料级配对其耐久性有很大影响。未来有必要建立纤维类型与性能、混合料级配和耐久性之间的多参数综合评价指标体系，以实现对不同纤维沥青混合料耐久性的定向调控。竹纤维是木质素纤维的可靠替代品，未来可进一步开展改善其表面性能和分散均匀性的研究。
