Abstract:

To solve the engineering problems of basalt fiber (BF) with smooth surface, low surface energy and weak bonding with asphalt, nano-SiO₂ grafted BF (SiO₂-BF) were prepared using chemical grafting method with nano-SiO₂ as grafting material and silane coupling agent (KH550) as linker. The changes in the surface micromorphology and functional groups of SiO₂-BF were analyzed by SEM and FT-IR tests. Using molecular dynamics simulation software Materials Studio, the interface model of SiO₂-BF with asphalt and the interface model of SiO₂-BF pullout were established to study the interfacial cohesive performance of SiO₂-BF with asphalt and its bond failure behavior, respectively. The results showed that the nano-SiO₂ was uniformly coated on the surface of BF and the Si－O－Si antisymmetric telescoping vibration peak of SiO₂-BF at 1082cm^-1 increased significantly, indicating that the nano-SiO₂ was stably grafted on the surface of BF. Compared with the original BF, the interfacial energy between SiO₂-BF and asphalt increased by 32.10%, 33.99%, 27.73% and 6.85% at 298K, 323K, 353K and 438K, respectively. It showed that the cohesive performance between SiO₂-BF and asphalt was significantly higher than the original BF. When the tensile speed was 0.001nm²/ps, the original BF and SiO₂-BF indicated cohesive failure with the asphalt. When the tensile speed was 0.003nm²/ps, the original BF and asphalt was adhesive failure, while SiO₂-BF and asphalt was cohesive failure, and the peak stress of SiO₂-BF was 96.19% higher than that of the original BF. It showed that nano-SiO₂ grafted BF significantly enhanced its bonding strength with asphalt.

Key words: nano-SiO₂, basalt fiber, asphalt, cohesive performance, failure behavior

摘要：

针对玄武岩纤维（basalt fiber，BF）表面光滑、表面能低、与沥青界面黏结强度不强等工程问题，以纳米SiO₂为接枝材料，硅烷偶联剂（KH550）为连接剂，运用化学接枝法，制备了纳米SiO₂接枝玄武岩纤维（SiO₂-BF），通过SEM和FT-IR试验，分析了玄武岩纤维表面微观形貌和官能团变化特征；并运用分子动力学模拟软件Materials Studio，分别建立了SiO₂-BF与沥青界面模型和SiO₂-BF拔出界面模型，研究了SiO₂-BF与沥青的界面黏结性能及其黏结失效行为。结果表明：纳米SiO₂均匀裹覆在BF表面，且1082cm^-1处SiO₂-BF的Si－O－Si反对称伸缩振动峰明显增大，说明BF表面稳定接枝了纳米SiO₂；温度在298K、323K、353K和438K时，SiO₂-BF与沥青的界面能较原样BF分别增加了32.10%、33.99%、27.73%和6.85%，说明SiO₂-BF与沥青的黏结性能显著高于未接枝时的水平；当拉伸速度为0.001nm²/ps时，原样BF和SiO₂-BF与沥青界面均表现为黏聚失效，当拉伸速度为0.003nm²/ps时，原样BF与沥青为黏附失效，而SiO₂-BF与沥青界面为黏聚失效，且SiO₂-BF较原样BF应力峰值提高了96.19%，说明纳米SiO₂接枝BF显著增强了其与沥青的黏结强度。

关键词: 纳米SiO₂, 玄武岩纤维, 沥青, 黏结性能, 失效行为