低场核磁共振低温测孔技术表征硬化水泥浆体孔结构
作者:
作者单位:

同济大学 先进土木工程材料教育部重点实验室,上海 201804

作者简介:

佘安明(1982—),男,江苏扬州人,同济大学讲师,硕士生导师,博士.E-mail: sheanming@tongji.edu.cn

通讯作者:

姚 武(1966—),男,江苏镇江人,同济大学教授,博士生导师,博士.E-mail: yaowuk@tongji.edu.cn

中图分类号:

TU528.45

基金项目:

“十三五”国家重点研发计划项目(2019YFC1906203)


Characterization of Pore Structure in Hardened Cement Paste by Low Field NMR Cryoporometry
Author:
Affiliation:

Key Laboratory of Advanced Civil Engineering Materials of Ministry of Education, Tongji University, Shanghai 201804, China

Fund Project:

National Key Research and Development Program of China (2019YFC1906203)

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    摘要:

    采用低场核磁共振低温测孔技术表征了硬化水泥浆体的孔结构,探讨了水灰比、龄期及掺和料对其孔结构的影响.结果表明:随着水灰比的增大,硬化水泥浆体的毛细孔含量增大,凝胶孔占比逐渐降低,加权平均孔径逐渐增大;龄期延长使凝胶孔占比逐渐增大,加权平均孔径逐渐降低;纳米CaCO3主要增加40 nm左右毛细孔的量,粉煤灰则主要增加60 nm左右毛细孔的量,活性更强的硅灰则有更强的细化孔径的作用.

    Abstract:

    The pore structure of hardened cement paste was characterized by low field nuclear magnetic resonance (NMR) cryoporometry. The effects of water-cement ratios, ages and admixtures on the pore structure were investigated. The results show that with the increase of water-cement ratio, the capillary pore content of hardened cement paste increases, the proportion of gel pore decreases gradually, and the weighted average pore size increases gradually. With the increase of age, the proportion of gel pore increases gradually and the weighted average pore size decreases gradually. Nano calcium carbonate mainly increases the amount of small capillary pores at about 40 nm, while fly ash mainly increases the amount of large capillary pores at about 60 nm, and silica fume with stronger activity has a stronger role in refining pore size.

    表 5 CE04、CE04+NC和CE04+FA的孔隙率、凝胶孔占比及Table 5 Porosity, φgel and DWMV of CE04, CE04+FA and
    表 2 浆体的配合比Table 2 Mix proportion of pastes
    表 6 CE04和CE04+SF的孔隙率、凝胶孔占比及加权平均孔径Table 6 Porosity,φgel and DWMV of CE04, CE04+FA and CE04+NC
    图1 不同水灰比硬化水泥浆体孔径分布曲线(7 d)Fig.1 Pore size distribution curves of hardened cement pastes with different mW/mC (7 d)
    图2 不同龄期下CE03的孔径分布曲线Fig.2 Pore size distribution curves of CE03 at different ages
    图3 CE04、CE04+NC和CE04+FA的孔径分布曲线(28 d)Fig.3 Pore size distribution curves of CE04, CE04+FA and CE04+NC (28 d)
    图4 CE04和CE04+SF的孔径分布曲线(28 d)Fig.4 Pore size distribution curves of CE04 and CE04+SF (28 d)
    表 3 不同水灰比硬化水泥浆体的孔隙率、凝胶孔占比及加权平均孔径(7 d)Table 3 Porosity, φgel and DWMV of hardened cement pastes with different mW/mC (7 d)
    表 4 不同龄期下CE03的孔隙率、凝胶孔占比及加权平均孔径Table 4 Porosity, φgel and DWMV of CE03 at different ages
    表 1 原材料的化学组成Table 1 Chemical compositions of raw materials w/%
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佘安明,马坤,王中平,姚武.低场核磁共振低温测孔技术表征硬化水泥浆体孔结构[J].建筑材料学报,2021,24(5):916-920

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  • 收稿日期:2021-03-21
  • 最后修改日期:2021-04-28
  • 录用日期:2021-06-04
  • 在线发布日期: 2021-12-15
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