用纳米压痕技术表征超高韧性水泥基复合材料(ECC)的裂缝自愈合特性

Nanoindentation Characterization of Self-healing Engineered Cementitious Composites(ECC)Materials

为了探究ECC裂缝自愈合体系中不同物相的微观力学性能,应用纳米压痕技术对经历10个干湿循环环境后裂缝自愈合ECC体系中不同物相的荷载-位移、接触刚度-位移、弹性模量及硬度进行了研究。结果表明:当荷载相同时,压入深度大小顺序为:纤维>ITZ>SHP>基体>粉煤灰>砂子;接触刚度与压入深度近似呈线性关系;粉煤灰和砂子的弹性模量及硬度是体系中最高的,远远高于其他相,其次是基体,接下来是SHP、ITZ,最差的是纤维。

In order to explore the micro mechanical properties of different phases in self-healing ECC,by nanoindentation technique,load-displacement,contact stiffness-displacement,elastic modulus and hardness for different phases in self-healing ECC under 10wet/dry conditioning cycles were investigated in this paper.The results show that the order of indentation depth at the same indentation load is：fiberITZSHPmatrixfly ashquartz.The contact stiffness during loading increases with indentation depth approximatively linearly.The elastic modulus and hardness of fly ash and quartz are the highest,far higher than other phases in selfhealing ECC,followed by matrix,then the next are SHP,ITZ,and the worst is fiber.