院报 ›› 2022, Vol. 39 ›› Issue (9): 124-130.DOI: 10.11988/ckyyb.20210585

• 水工结构与材料 • 上一篇    下一篇

K2O/Na2O对不同水泥基材料早期收缩及开裂的影响

李洋1,2, 张晖1, 蒋科1, 袁俊1, 殷海波1   

  1. 1. 工程质量检测中心,武汉 430072;
    2.武昌理工学院 城市智能建造学院,武汉 430223
  • 收稿日期:2021-06-16 修回日期:2021-07-26 出版日期:2022-09-01 发布日期:2022-09-21
  • 作者简介:李 洋(1986-),男,湖北仙桃人,高级工程师,博士,研究方向为工程质量检测。E-mail:liyang@mail.crsri.cn
  • 基金资助:
    中央级公益性科研院所基本科研业务费项目(CKSF2017034/GC,CKSF2017032/GC,CKSF2019166/JC)

Influence of K2O/Na2O on Early-age Shrinkage and Cracking of Different Cement-based Materials

LI Yang1,2, ZHANG Hui1, JIANG Ke1, YUAN Jun1, YIN Hai-bo1   

  1. 1. Engineering Quality Inspection Center, Yangtze River Scientific Research Institute, Wuhan 430072, China;
    2. School of Intelligent Construction, Wuchang University of Technology, Wuhan 430223, China
  • Received:2021-06-16 Revised:2021-07-26 Online:2022-09-01 Published:2022-09-21

摘要: 通过外掺Na2SO4和K2SO4将低热硅酸盐水泥、中热硅酸盐水泥和普通硅酸盐水泥总碱含量调节至1.2%,并使K2O/Na2O (质量比)控制在0.4~13.7范围内,探讨了K2O/Na2O对3种水泥基材料收缩和开裂的影响。并基于微量热技术、电子显微镜技术和能谱技术,揭示了K2O/Na2O对不同水泥基材料收缩和开裂的影响机制。研究表明,随K2O/Na2O的增加,低热硅酸盐水泥和普通硅酸盐水泥的自收缩和干燥收缩增加,中热硅酸盐水泥的自收缩和干燥收缩先降低后增加,而不同水泥基材料开裂敏感性始终表现为增加。K2O/Na2O引起不同收缩特性的主要原因与水泥基材料水化进程有关,而不同的开裂敏感性,除与收缩性能相关外,还受水泥基材料水化产物水化硅酸钙(C-S-H)、氢氧化钙(CH)形貌及界面过渡区(ITZ)元素富集的影响。

关键词: K2O/Na2O, 收缩性能, 开裂性能, 微观形貌, 界面过渡区

Abstract: The total alkali content of low heat Portland cement, medium heat Portland cement and ordinary Portland cement were adjusted to 1.2% by adding Na2SO4 and K2SO4 respectively, in which the K2O/Na2O (by weight) were in the range of 0.4-13.7. The influence of alkali of different K2O/Na2O on shrinkage properties and cracking properties of cement-based materials were explored. Besides, with the help of microcalorimetry, scanning electron microscopy and energy dispersive spectroscopy, the influence mechanism of alkali of different K2O/Na2O on shrinkage properties and cracking properties of cement-based materials was revealed. The results show that with the increase of K2O/Na2O, the autogenous shrinkage and drying shrinkage of low-heat and ordinary Portland cement intensified, while those of medium-heat cemet first decreased and then increased, and the cracking sensitivity of different cement-based materials always increased. The difference in shrinkage properties caused by K2O/Na2O was related to the hydration process of cement-based materials. The difference in cracking sensitivity was not only related to shrinkage properties, but also affected by the morphology of hydrated calcium silicate (C-S-H), calcium hydroxide (CH) and the enrichment of elements in the interfacial transition zone (ITZ).

Key words: K2O/Na2O, shrinkage properties, cracking properties, micro-morphology, interfacial transition zone

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