基于原子力显微技术的混合料中沥青微尺度性能测试方法

A Method of Determination of Micro Scale Properties of Asphalt Components in Mixtures Based on Atomic Force Microscopy

摘要:

以沥青混合料试件为研究对象，探讨了原子力显微样本的制备方法.选取最大纵向起伏度和表面粗糙度两个指标对不同储存条件下的样本制备效果进行评定，提出采用低温冷冻措施保证AFM（atomic force microscope）样本平整度的制样方法；利用原子力显微技术的力学性能量化模块AFMQNM（atomic force microscopequantitative nano mechanical），选取沥青胶浆区域3个典型的观测区域，进行原子力显微测试及微尺度力学性能量化表征.研究结果表明，“冷冻保存、低温切割”的混合料试件样本制备方法能够满足AFM技术的观测要求；AFMQNM技术可以在混合料试件中直接测试沥青（胶浆）和矿质集料的模量和黏附性质，可有效区分不同的材料组分.

关键词:沥青混合料;原子力显微技术力学性能量化模块;样本制备;沥青胶浆;微尺度力学性能

Abstract:

The mixture specimen was selected as the research object and the preparation method of samples using atomic force microscopy were discussed. The maximum longitudinal distance and surface roughness of the sample surface were applied to evaluate samples in different storage conditions. The freezing method at lower temperature was recommended to ensure the flattnesss of sample surface. Then three areas in asphaltmineral filler mastic of mixtures surface were investigated using the function of quantitative Nano mechanical of atomic force microscopy(AFMQNM).The results show that the sample with freezing preservation and low temperature cutting could ensure the flatness of mixture samples， which meets the demand of AFM observation. The technology of AFMQNM can directly measure the microscale mechanic modulus and adhesion properties in mixture and effectively distinguish different material components. This study could provide a new idea for insitu evaluating aging degree of RAP asphalts.

Key words:asphalt mixture; atomic force microscopequantitative nano mechanical module; sample preparation; asphalt mastic; micro scale mechanical properties