| 摘要: |
| 采用亲水性的纳米SiO2粉体与P·Ⅰ42.5水泥制备了纳米SiO2改性水泥土钉注浆体.测定了不同纳米SiO2掺量下浆体的泌水层高度、扩散度和强度；采用X射线衍射（XRD）分析、热重差热（TG DTA）分析方法研究了不同龄期下纳米SiO2改性水泥土钉注浆体的微观结构与组成.结果表明：随着纳米SiO2掺量的增加，浆体的扩散度下降，而泌水层高度逐渐减小；掺入纳米SiO2可以提高浆体的抗压强度和抗折强度，尤其是后期抗压强度和抗折强度.纳米SiO2的最佳掺量为1.0%～2.0%（质量分数）.与纯水泥浆体相比，纳米SiO2改性水泥土钉注浆体中Ca（OH）2含量较少而C S H凝胶含量较多. |
| 关键词: 纳米SiO2 水泥 土钉注浆体 |
| DOI：10.3969/j.issn.1007 9629.2017.02.017 |
| 分类号: |
| 基金项目:浙江省教育厅科研项目（Y201432698） |
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| Study on Properties of Nano SiO2 Blended Cement Pastes for Grouting Soil Nailing |
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PAN Xiaoyan1, ZHANG Guangxing1, ZHANG Yanqing1, GAO Yongliang2
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1.Department of Civil Engineering, Tongji Zhejiang College, Jiaxing 314051, China;2.Zhejiang Jiaxing Sanyi Engineering Detection Co., Ltd., Jiaxing 314051, China
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| Abstract: |
| Nano SiO2 blended cement pastes for grouting soil nailing were produced， using hydrophilic nano SiO2 powders and P·Ⅰ42.5 cement as raw materials. Bleeding height， slump extension and strength of cement pastes containing different contents of nano SiO2 powders were measured. Microstructures and composition of nano SiO2 blended cement pastes at different ages were investigated by X ray diffractometry（XRD） and thermal gravity differential thermal analysis（TG DTA）. The results show that bleeding height and slump extension of cement pastes decreased with increasing nano SiO2 content. By blending nano SiO2 powders into cement pastes， the flexural strength and compressive strength of hardened cement pastes are enhanced， especially at later age. The optimum nano SiO2 content is 1.0%2.0%. Nano SiO2 blended cement pastes contain less Ca（OH）2 and more C S H gel than pure cement paste. |
| Key words: nano SiO2 cement grouting soil nailing |
