Characteristics of surface-treatment of nano-SiO2 on the transport properties of hardened cement pastes with different water-to-cement ratios
Characteristics of surface-treatment of nano-SiO2 on the transport properties of hardened cement pastes with different water-to-cement ratios
复制标题
纳米SiO2表面处理对不同水灰比硬化水泥浆体输运性能的影响
DOI：
10.1016/j.cemconcomp.2014.07.022
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发表时间：
2015-01-01
影响因子：
10.5
通讯作者：
Shah, Surendra P.
中科院分区：
文献类型：
--
作者：
Hou, Pengkun;Cheng, Xin;Shah, Surendra P.
降低混凝土结构表面部分的传输性能有利于提高其耐久性，因为它阻止了侵蚀剂的迁移。通过测定水灰比为0.26、0.38、0.60和1.0的硬化水泥浆体的吸水率和水蒸气透过系数，研究了平均粒径为20 nm的胶体纳米SiO2（CNS）及其前驱体正硅酸乙酯（TEOS）对硬化水泥浆体水化性能的影响，在样品首先在处理剂中浸泡1小时后。结果表明，CNS和TEOS能够通过改变孔结构来降低硬化水泥浆体的传输性能。CNS降低了大于约0.1 μ m的孔的阈值和体积，而TEOS降低了小于0.1 μ m的孔的阈值和体积，TEOS还在更大程度上降低了“墨水瓶”孔体积与喉孔体积的比率。发现小于0.1/0.01 μ m的毛细孔的体积与传输性能之间存在线性关系，这可以归因于用CNS或TEOS表面处理后硬化水泥浆体的传输性能的降低。(C)2014爱思唯尔有限公司版权所有。
A reduced transport property of the superficial part of concrete structures is beneficial for enhancing their durability, due to the blocking of the migration of aggressive agents. In this study, influences of colloidal nano-SiO2 (CNS) with a mean particle size of 20 nm and its precursor, tetraethoxysilane (TEOS), on the transport properties of hardened cement pastes with water-to-cement ratios of 0.26, 0.38, 0.60 and 1.0 by mass were investigated by measuring the water absorption ratio and water vapor transmission coefficient, after the samples were first soaked in treatment agents for 1 h. Results showed that CNS and TEOS are capable of reducing the transport properties of hardened cement pastes by altering the pore structures. CNS reduces the threshold value and volum e of the pores larger than about 0.1 mu m, while TEOS reduces the threshold value and volume of the pores smaller than 0.1 mu m, and TEOS also reduces the ratio of the 'ink-bottle' pore volume to the throat pore volume to a greater extent. A linear relationship between the volume of capillary pores smaller than 0.1/0.01 mu m and the transport property was found, which can be ascribed to the reduction of transport properties of hardened cement pastes after surface-treatment with CNS or TEOS. (C) 2014 Elsevier Ltd. All rights reserved.