| 引用本文: | 张茂花,孙彦宇.干湿循环作用下纳米混凝土的抗Cl-渗透性能[J].哈尔滨工业大学学报,2019,51(8):167.DOI:10.11918/j.issn.0367-6234.201904097 |
| ZHANG Maohua,SUN Yanyu.Cl- penetration resistance of concrete with nano-particles under the action of dry-wet cycle[J].Journal of Harbin Institute of Technology,2019,51(8):167.DOI:10.11918/j.issn.0367-6234.201904097 |
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| 摘要: |
| 干湿循环和氯离子（Cl-）渗透是影响海工混凝土耐久性的主要因素,为研究不同环境条件及掺加纳米颗粒对海工混凝土抗Cl-渗透性能的影响,分别将不同掺量的纳米SiO2和纳米Fe3O4掺入到普通混凝土中,通过干湿循环和全浸泡两种方式进行Cl-渗透对比试验,采用化学滴定法测得混凝土内不同深度的Cl-含量.试验结果表明:干湿循环作用加速了Cl-向混凝土内的迁移,并使混凝土的总、自由、结合Cl-含量及Cl-结合能力均高于相同龄期的全浸泡试件,且随着干湿循环次数的增加两者Cl-含量的差值越来越大；两种环境条件下,纳米混凝土的总、自由Cl-含量均低于普通混凝土,而结合Cl-含量和Cl-结合能力均高于普通混凝土,两种纳米颗粒的最佳掺量都是2%,且纳米SiO2的改善效果优于纳米Fe3O4.纳米颗粒的表面效应和填充效应改善了混凝土的孔结构,造成Cl-在混凝土内迁移困难；不同掺量的纳米SiO2和纳米Fe3O4可以不同程度的提高水化产物对Cl-的化学结合和物理吸附能力,减少混凝土内的自由Cl-含量,从而提高海工混凝土的抗Cl-渗透性能.本文研究成果可为海工混凝土的耐久性设计提供参考. |
| 关键词: 海工混凝土 纳米颗粒 干湿循环 全浸泡 Cl-渗透 耐久性 |
| DOI：10.11918/j.issn.0367-6234.201904097 |
| 分类号:TU528 |
| 文献标识码:A |
| 基金项目:国家自然科学基金(51878130)；黑龙江省博士后科研启动金项目(LHB-Q13001)；中央高校基本科研业务费专项基金(2013CBQ02) |
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| Cl- penetration resistance of concrete with nano-particles under the action of dry-wet cycle |
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ZHANG Maohua,SUN Yanyu
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(School of Civil Engineering, Northeast Forestry University, Harbin 150040, China)
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| Abstract: |
| Dry-wet cycle and chloride ion (Cl-) penetration are the main factors affecting the durability of marine concrete. To study the influences of different environmental conditions and the addition of nano-particles on the Cl-penetration resistance of marine concrete, nano-SiO2 and nano-Fe3O4 were respectively added into ordinary concrete with different amounts, and the contrast test of Cl-penetration was carried out by dry-wet cycle and full immersion, then the Cl- content in concrete at different depths by chemical titration was measured. The test results show that dry-wet cycle accelerates the Cl-migration to the inner of concrete, which makes that the total Cl- content, free Cl- content and bound Cl- content in concrete and the Cl- binding capacity of concrete under dry-wet circle condition are all higher than those under full immersion condition at the same age, and the difference in Cl- content between the two environmental conditions becomes more and more larger with the increasing number of dry-wet cycles. Under the two environmental conditions, the total Cl- content and free Cl- content in concrete with nano-particles are all lower than those in ordinary concrete, but the bound Cl- content and the Cl- binding capacity are all higher than those in ordinary concrete. The optimum amount of two nano-particles in marine concrete is 2%, and the Cl-penetration resistance of concrete with nano-SiO2 is superior to that of concrete with the same amount of nano-Fe3O4. The surface effect and filling effect of nano-particles improve the pore structure of concrete, resulting in the Cl-migration in concrete difficult. Both nano-SiO2 and nano-Fe3O4 with different amounts can enhance the chemical binding capacity and physical adsorption capacity of hydrated products to Cl- in different extent, which can reduce the free Cl- content in concrete to improve the Cl- penetration resistance of marine concrete. This study can provide references for the durability design of marine concrete. |
| Key words: marine concrete nano-particles dry-wet cycle full immersion Cl-penetration durability |
