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鉴于混凝土微观结构对宏观性能的重要影响,利用纳米划痕试验方法,对常规水灰比配比的混凝土样品骨料-水泥浆体微观界面及界面过渡区进行了表征研究.基于纳米划痕试验方法和扫描电镜显微技术,对于样品微观情况下的骨料-水泥浆体界面进行了表征分析,并对表征结果经过多个高斯分布拟合的统计学分析方法得到基于界面位置的结构划痕硬度分布情况.通过划痕硬度与骨料-浆体界面的距离变化,定义了骨料和水泥浆体之间的界面过渡区,并得到界面过渡区厚度约为40μm,界面过渡区划痕硬度约为水泥浆料硬度的75%左右.通过比较划痕断裂韧性与宏观试验结果,证明利用纳米划痕试验可以初步分析材料断裂韧性.本研究为更好地研究混凝土微观性能对宏观力学性能的影响提供了可靠的数据支持,也为评价混凝土微观界面力学性能提供了一种新的可行方法.
In view of the important influence of the microstructure of the concrete on the macroscopic performance, the nano-scratch test method was used to characterize the microstructure and interface transition zone of the concrete samples with the conventional water-cement ratio. Based on the nano-scratch test Method and scanning electron microscopy were used to characterize and analyze the interface of aggregate-cement paste in the microscopic situation of the sample. The statistical results of the Gaussian distribution fitting were used to obtain the structural scratches based on the interface position The distribution of hardness is defined as the interface transition between aggregate and cement paste through the change of the scratch hardness and the distance between the aggregate and the slurry interface.The thickness of the transition zone is about 40μm and the scratch hardness About 75% of the hardness of the cement slurry.By comparing the fracture toughness and macroscopic test results, it is proved that the fracture toughness of the material can be preliminary analyzed by nano-scratch test.This study is to better study the mechanical properties of macroscopically The impact provided reliable data support and provided a new and viable method for evaluating the mechanical properties of concrete micro-interfaces.