玄武岩纤维与木质素纤维沥青胶浆流变性能研究
作者简介:
张翔,工程师,E⁃mail:1277938108@ qq. com
作者单位:
1.华设设计集团股份有限公司,江苏南京 210014;2.长安大学公路学院,陕西西安 710064;3.中交第二公路工程局有限公司工程设计研究院,陕西西安 710065
基金项目:
∗国家自然科学基金(51308064)
摘要:
木质素纤维作为最早应用于沥青混合料的纤维材料,存在高温易变形失效和长期耐久性不足的问题。基于此,对比研究木质素纤维与玄武岩纤维在不同温度、不同掺量下对沥青胶浆的影响,通过锥入度、动态剪切流变(DSR)、弯曲梁流变等试验评价沥青胶浆流变性能。研究结果表明:2 种纤维均能在沥青胶浆中形成三维网状结构,有效提高沥青胶浆的抗永久变形和低温抗裂性;纤维通过嵌合作用提高了沥青胶浆的稠度,其抗剪强度对应增强,且相较于木质素纤维,玄武岩纤维的复数模量更高,相位角更小,储存能更大,损耗能减小,车辙因子更高,从而表现出更优异的流变性能;玄武岩纤维的劲度变化率较高,表现出更好的阻滞作用和传力作用,低温抗裂性表现更优,但纤维掺量超过 3.9%后,2 种纤维的低温抗裂性反而降低;另外相较于玄武岩纤维,木质素纤维表现出明显的温度敏感性,在不同温度下有不同的变化趋势,玄武岩纤维对沥青胶浆流变性能的改性效果更好。

English:
Lignin is the earliest fibre used in asphalt mastic, but it is prone to deformation and failure athigh temperature and has poor long⁃term performance. Based on this, a comparative study of lignin fibreand basalt fibre at different temperatures, different dosage of asphalt mastic, through the cone penetrationexperiment, DSR experiments, bending beam rheological test to characterize the rheological properties ofasphalt mastic, the results show that the two types of fibers can be distributed in asphalt mastic to form athree⁃dimensional network structure, After the addition of the fibres, the consistency of the asphalt masticis increased due to the embedding effect of the fibres, and the shear strength is also increasedaccordingly. The complex modulus of basalt fibres is higher than that of lignin fibres, the phase angle isreduced, the strain hysteresis is reduced, the elasticity component is increased, the storage energy isgreater, the loss energy is reduced, the permanent deformation is reduced and the rutting factor is higher,which shows better rheological performance. And the basalt fibre has a higher rate of change of strength,which shows a better blocking effect and force transmission, and a better low⁃temperature crackingresistance, but the low⁃temperature cracking resistance of the two types of fibres tends to be reduced afterthe fibre doping exceeds 3.9%. And the lignin fibre is more sensitive to temperature than the basaltfibre,with different trends at different temperatures. In summary, the basalt fibre showed better rheological properties for asphalt mortar.