基于纳米压痕的玄武岩纤维沥青混凝土微观力学性能研究

Research on the microscopic mechanical properties of basalt fiber asphalt concrete based on nanoindentation

摘要

【目的】为了探究玄武岩纤维沥青混凝土(BFAC)的微观力学性能,【方法】结合纳米压痕试验与有限元数值模拟,深入研究BFAC各组成相的力学响应。基于Abaqus软件构建包含沥青基体、骨料、骨料-沥青过渡界面与纤维的四相三维模型,采用静力隐式算法模拟压痕过程,获取各相在荷载-位移响应、模量、硬度及蠕变行为的演化规律。【结果】研究结果表明:BFAC各相的力学性能差异显著,试验测得沥青基体、骨料、纤维及过渡界面的杨氏模量分别为1.73 GPa、76.69 GPa、120.60 GPa和34.39 GPa。数值模拟与试验曲线吻合度较高,杨氏模量误差小于5%,验证了所建立模型在BFAC微观力学行为响应与分析中的有效性和准确性。【结论】BFAC中沥青基体模量与硬度最低,塑性变形与蠕变响应最为显著,骨料与纤维则表现出高模量、高硬度及优异的抗变形能力,蠕变位移均小于70 nm,过渡界面的性能介于骨料和沥青基体之间。场分析表明,压痕点处的位移场、应力场及应变场均呈现出压头下方高、远场低的分布特征,位移、应力及应变等值线呈类椭圆形向内部扩展,且随深度增加其量值逐渐衰减。此外,还揭示了压头几何形状对压入响应的影响机制。相较于玻氏压头,球形压头因接触面积小,其加载曲线斜率小,在最大荷载下压入深度比玻氏压头增加约12%~28%。研究结果可为水工沥青混凝土材料的结构设计与性能优化提供参考。

Abstract

[Objective] To investigate the micromechanical properties of basalt fiber asphalt concrete(BFAC), [Methods] a nanoindentation tests with finite element numerical simulations was conducted to thoroughly examine the mechanical responses of the constituent phases of BFAC. A four-phase three-dimensional model comprising the asphalt matrix, aggregate, aggregateasphalt transition interface, and fiber was constructed using Abaqus software. The static implicit algorithm was employed to simulate the indentation process, thereby capturing the evolution patterns of load-displacement response, modulus, hardness, and creep behavior for each phase. [Results] The findings reveal significant variations in the mechanical properties of the BFAC phases. The Young' s moduli of the asphalt matrix, aggregate, fiber, and transition interface were measured at 1. 73 GPa, 76. 69 GPa, 120. 60 GPa, and 34. 39 GPa, respectively. The numerical simulations exhibited a high degree of concordance with the experimental curves, with Young's modulus errors below 5%, thereby validating the efficacy and accuracy of the model in analyzing the micromechanical behavior of BFAC. [Conclusion] The asphalt matrix in BFAC demonstrated the lowest modulus and hardness, with the most pronounced plastic deformation and creep response. In contrast, the aggregate and fiber exhibited high modulus, high hardness, and superior deformation resistance, with creep displacements all below 70 nm. The transition interface' s performance was intermediate between the aggregate and asphalt matrix. Field analysis indicated that the displacement, stress, and strain fields at the indentation point exhibited a distribution characteristic of high values beneath the indenter and low values in the far field. The contours of displacement, stress, and strain expanded elliptically inward, with their magnitudes gradually attenuating with increasing depth. Additionally, the study elucidated the influence mechanism of indenter geometry on the indentation response. Compared to the Berkovich indenter, the spherical indenter, due to its smaller contact area, with a smaller slope in the loading curve. increased the indentation depth by approximately 12% to 28% at maximum load. These findings provide valuable insights for the structural design and performance optimization of hydraulic asphalt concrete materials.

关键词

玄武岩纤维沥青混凝土 / 纳米压痕 / 数值模拟 / 微观力学性能 / 影响因素 / 杨氏模量 / 过渡界面

Key words

basalt fiber asphalt concrete / nano-indentation / numerical simulation / micro-mechanical properties / influencing factor / Young's moduli / transition interface

基金资助

国家自然科学基金项目(52379127)

那河大坝心墙玄武岩纤维沥青混凝土断裂性能研究项目(QHNH202005)