采用纳米压痕及动态模量图研究C-S-H凝胶/水泥颗粒界面的纳米力学性能（英文）  

Nanomechanical properties of C-S-H gel/cement grain interface by using nanoindentation and modulus mapping

作　　者：Jing XU David J.CORR Surendra P.SHAH 

机构地区：[1]Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Tongji University [2]Department of Civil and Environmental Engineering, Northwestern University

出　　处：《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》2015年第1期38-46,共9页浙江大学学报（英文版）A辑（应用物理与工程）

基　　金：Project supported by the National Natural Science Foundation of China(No.51378011)

摘　　要：目的:揭示水泥基材料中C-S-H凝胶/水泥颗粒界面的尺寸及微观力学特性,为从纳米尺度理解水泥基材料的性能提供依据。创新点:采用动态模量图技术对C-S-H凝胶/水泥颗粒界面微区的尺度及力学行为进行研究,借助动态模量图的高分辨性,可获得该微区精确且有效的信息。方法:对比利用纳米压痕及动态模量图对C-S-H凝胶/水泥颗粒界面进行研究。结论:纳米压痕仅能粗略估计界面微区的尺寸及力学参量,相比之下,动态模量图的分辨率要高出2个数量级(表2),因此可获得更精确的测量值。C-S-H凝胶/水泥颗粒界面的尺寸在250 nm左右,模量值介于60 GPa和70 GPa之间。此界面区可认为是包覆水泥颗粒周围的一层紧密的水化层结构,其致密性将阻止内部水泥的进一步水化。Investigation on the mechanical properties of cement-based materials at micron and sub-micron scales is important for understanding its overall performance. Recent progress in experimental nanomechanics opens new access to nano-engineering of cement-based composites. In this study, nanoindentation and viscoelastic modulus mapping were employed to study the interfacial properties. The interface width measured by modulus mapping was around 250 nm as compared to a rough estimation of less than 5μm by nanoindentation, due to the fact that 2 orders of magnitude increase in spatial resolution could be achieved by modulus mapping. Both the nanoindetation and modulus mapping results indicated that the modulus of the interface falls between 60–70 GPa. The packing density in the interface was non-uniform as two peaks of value were observed for the storage modulus distribution. This interface could be regarded as a dense hydration coating around cement grains, which was less permeable and hindered the further hydration of cement.

关 键 词：水泥基材料 界面 纳米力学特性 动态模量图 

分 类 号：TU528[建筑科学—建筑技术科学]