纳米TiO2分散性对水泥水化和性能的影响
作者:
作者单位:

1.湖南科技大学 土木工程学院,湖南 湘潭 411201;2.湖南省智慧建造装配式被动房工程技术研究中心,湖南 湘潭 411201;3.广东盖特奇新材料科技有限公司,广东 清远 511600

作者简介:

朱食丰(1997—),男,湖南邵阳人,湖南科技大学硕士生.E-mail:954343025@qq.com

通讯作者:

王功勋(1979—),男,湖北仙桃人,湖南科技大学副教授,硕士生导师,博士.E-mail: wanggx@hnust.edu.cn

中图分类号:

TU528

基金项目:

湖南省教育厅重点项目(19A164,19K033);国家级大学生创新创业训练项目(S202010534006);清远市科技计划项目(2018A021);湖南省交通运输厅科技进步与创新计划项目(202114)


Effect of Nano-TiO2 Dispersibility on the Mechanics, Hydration Degree and Microscopic Properties of Cement Paste
Author:
Affiliation:

1.School of Civil Engineering, Hunan University of Science and Technology, Xiangtan 411201, China;2.Hunan Engineering Research Center for Intelligently Prefabricated Passive House, Xiangtan 411201, China;3.Guangdong Gaiteqi New Materials Technology Co., Ltd., Qingyuan 511600, China

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    摘要:

    采用磁力搅拌+超声波分散+聚羧酸高效减水剂方法来提高纳米TiO2(NT)在水泥净浆中的分散性与稳定性,研究了不同掺量NT对水泥净浆力学性能的影响,通过水化热、热重-差示扫描量热(TG-DSC)分析、压汞(MIP)等测试方法,研究NT对水泥水化性能的影响机理.结果表明:采取磁力搅拌20 min、超声波分散15 min、再磁力搅拌15 min,并辅以聚羧酸高效减水剂,可制得分散稳定的NT悬浮液;当NT掺量为2.0%时,水泥净浆的抗压强度最大,且在相同掺量下,使用悬浮液法制备的水泥净浆力学性能高于干混法;NT可显著缩短水泥水化的诱导期,提高水泥早期水化放热速率,改变CH的结晶度及取向,并优化硬化水泥净浆内部的孔隙结构,提高其力学性能.

    Abstract:

    The method of magnetic stirring combined with ultrasonic dispersion and addition of polycarboxylic acid water reducer was used to improve the dispersion and stability of nano-TiO2(NT) in cement paste, and the effect of different content of NT on the mechanical properties of cement paste was studied. Measurement of hydration heat, thermogravimetric-differential scanning calorimetry (TG-DSC) and mercury intrusion method(MIP) were used to study the influence mechanism of NT on cement hydration performance. The results show that dispersion and stable NT suspension can be prepared by adopting magnetic stirring for 20 minutes, ultrasonic dispersion for 15 minutes, and magnetic stirring for 15 minutes, supplemented with polycarboxylic acid water reducer. When the content of NT is 2%, the compressive strength of cement paste is the largest, and under the condition of the same NT content, the mechanical properties of cement paste prepared with the suspension are higher than that of the dry mixing method. NT can significantly shorten the induction period of cement hydration, increase the rate of early cement hydration heat release, change the crystallinity and orientation of CH, optimize the internal pore structure of the hardened cement paste, and improve its mechanical properties.

    表 1 水泥净浆的配合比Table 1 Mix proportion of cement pastes
    表 2 水泥净浆的孔结构参数Table 2 Characteristic parameters of pore structure of cement pastes
    图1 不同分散方式下NT悬浮液的初始粒径Fig.1 Initial particle size of NT suspension under different dispersion methods
    图2 不同分散方法下悬浮液的稳定性Fig.2 Stability of suspension under different mix methods
    图3 减水剂对悬浮液分散性及稳定性的影响Fig.3 Effect of water reducer on dispersion and stability of nano-TiO2 suspension
    图4 NT悬浮液的稳定性Fig.4 Stability of NT suspension
    图5 不同分散方式对水泥净浆强度的影响Fig.5 Influence of different dispersion methods on strength of cement pastes
    图6 采用悬浮液法制备的掺NT水泥净浆的抗压强度Fig.6 Compressive strength of cement pastes with NT prepared with the suspension
    图7 NT对水泥水化放热的影响Fig.7 Effect of NT on the heat of hydration of cement pastes
    图8 水泥净浆的热分析Fig.8 Thermal analysis of cement pastes
    图9 水泥净浆的CH含量Fig.9 CH content in cement pastes
    图10 水泥净浆水化3、28 d时的SEM图Fig.10 SEM images of cement pastes at 3, 28 d
    图11 不同养护龄期下水泥净浆的孔体积-孔径分布曲线Fig.11 Pore volume-pore diameter distribution curves of cement pastes under different curing ages
    图12 水泥净浆的孔径分布Fig.12 Pore diameter distribution of cement pastes
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引用本文

朱食丰,王功勋,邓静,刘福财,肖敏.纳米TiO2分散性对水泥水化和性能的影响[J].建筑材料学报,2022,25(8):843-852

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  • 收稿日期:2021-06-03
  • 最后修改日期:2021-08-17
  • 在线发布日期: 2023-09-15
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