| 摘要: |
| 采用橡胶粉(RP)替代部分细集料制备橡胶水泥基复合材料（RCC），分析了RP体积分数对RCC试件抗压强度劣化规律的影响，同时复掺纳米SiO2（NS）对RCC试件进一步改性，结合毛细吸水试验以及微观结构分析，揭示了NS对RCC试件的增强作用机理.结果表明：掺RP后，RCC试件抗压时的延性增大，抗压强度下降速率随RP体积分数的增加呈3个明显阶段，掺RP对RCC试件早龄期抗压强度增长尤为不利;复掺1%质量分数的NS后，RP体积分数为5%和10%的RCC试件抗压强度分别提高了198%和181%，毛细吸水系数分别下降了289%和306%；环境扫描电镜（ESEM）以及能谱分析结果显示，掺NS后RCC试件的RP界面过渡区缺陷减少，材料内部孔隙结构得到细化，同时生成了大量低钙硅比的C S H凝胶相. |
| 关键词: 水泥基复合材料 橡胶粉 纳米SiO2 延性 毛细吸水作用 微观结构 |
| DOI：103969/j.issn.1007 9629201902010 |
| 分类号: |
| 基金项目:浙江省重点研发计划(2018C03029)；浙江省公路管理局科技计划项目(2018H27) |
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| Effect of Nano SiO2/Rubber Powder on Compressive Properties and Microstructure of Rubberized Cementitious Composites（RCC） |
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ZHANG Wei, YIN Chenglong, HUANG Zhiyi
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College of Civil Engineering and Architecture, Zhejiang University, Hangzhou 310000, China
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| Abstract: |
| Rubber powder（RP）was used to replace part of fine aggregates to produce rubberized cementitious composites (RCC) and the effect of RP volume fraction on degradation of RCC compressive strength was investigated. Then, nano SiO2 (NS) was added into RCC for further modification, combined with capillary water absorption test and microstructure analysis, the enhancement mechanism of NS on RCC was revealed. The results show that after mixing with RP, the compressive ductility of RCC increases, while the decline rate of compressive strength with the increase of RP volume fraction shows three stages and RP especially retards the early age growth of RCC strength. After the addition of 1%(by mass) NS, the compressive strength of RCC specimens with 5% and 10% rubber powder increases by 198% and 181% respectively, while the capillary water absorption coefficient decreases by 289% and 306% respectively. The results of ESEM test and energy spectrum analysis show that the defects in the interfacial transition zone of the rubber powder after adding NS are reduced, and the internal pore structure of RCC is refined. Meanwhile, masses of low calcium silicon ratio C S H gel phase are generated. |
| Key words: cementitious composite rubber powder(RP) nano SiO2 ductility capillary water absorption microstructure |
