纳米改性混凝土界面过渡区的多尺度表征  

Multi-scale Characterization of Interfacial Transition Zone in Nano-Modified Concrete

作　　者：徐晶[1] 王彬彬[1] 赵思晨 XU J ing WANG Binbin ZHAO Sichen(Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Tongii University, Shanghai 201804, China)

机构地区：[1]同济大学先进土木工程材料教育部重点实验室,上海201804

出　　处：《建筑材料学报》2017年第1期7-11,共5页Journal of Building Materials

基　　金：国家自然科学基金资助项目(51378011)

摘　　要：从多尺度综合研究了纳米SiO_2对混凝土界面过渡区早期力学性能的影响.在宏观尺度上,主要测试了纳米改性混凝土的弹性模量及抗压、抗折强度,在微观尺度上,采用纳米压痕对其界面过渡区进行了压痕模量及其频数分布分析.结果表明:掺入纳米SiO_2后,无论水泥石还是混凝土,其早期强度及弹性模量均有所提高,且混凝土强度的提高尤为明显;纳米改性混凝土界面区的孔隙和缺陷显著减少,且形成了更高密度的C-S-H凝胶相,使其压痕模量与水泥石的压痕模量接近.The effect of nano-SiO2 on the early mechanical properties of interracial transition zone in concrete was studied at multi-scale levels. At macrolevel, the static modulus of elasticity, compressive and flexural strength were measured; at microlevel, the values and distribution of indentation modulus in inter- facial transition zone were analyzed by nano-indentation. Results show that the addition of nano-SiO2 improves the early strength and modulus of both cement paste and concrete, in particular, a much significant increase of strength for concrete was observed. The amount of micro-pores and defects decreases remark- ably and C-S-H gel with higher density forms in ITZ of concrete modified by nano-SiO2, thus the indentation modulus of ITZ is much closer to that of bulk paste.

关 键 词：界面过渡区 纳米SIO2 纳米压痕 弹性模量 

分 类 号：TU528.01[建筑科学—建筑技术科学]