| 摘要: |
| 从多尺度综合研究了纳米SiO2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SiO2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. |
| 关键词: 界面过渡区 纳米SiO2 纳米压痕 弹性模量 |
| DOI：10.3969/j.issn.1007 9629.2017.01.002 |
| 分类号: |
| 基金项目:国家自然科学基金资助项目（51378011） |
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| Multi scale Characterization of Interfacial Transition Zone in Nano Modified Concrete |
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XU Jing, WANG Binbin, ZHAO Sichen
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Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Tongii University, Shanghai 201804, China
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| Abstract: |
| The effect of nano SiO2 on the early mechanical properties of interfacial 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 interfacial 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 remarkably 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. |
| Key words: interfacial transition zone(ITZ) nano SiO2 nano indentation elastic modulus |
