长江科学院院报 ›› 2021, Vol. 38 ›› Issue (8): 133-138.DOI: 10.11988/ckyyb.20200519

• 水工结构与材料 • 上一篇    下一篇

腐蚀介质下粉煤灰混凝土宏微观性能的时变损伤

王宗熙, 姚占全, 何梁, 吴晗晗, 刘紫玫   

  1. 内蒙古农业大学 水利与土木建筑工程学院,呼和浩特 010018
  • 收稿日期:2020-06-08 修回日期:2020-08-24 出版日期:2021-08-01 发布日期:2021-08-06
  • 通讯作者: 姚占全(1971-),男,内蒙古乌兰察布人,教授,博士,主要从事建筑材料、磁性功能材料研究。E-mail: ndyzq@imau.edu.cn
  • 作者简介:王宗熙(1994-),男,山东菏泽人,硕士研究生,主要从事混凝土材料与结构耐久性研究。E-mail: wangzong xi99@163.com
  • 基金资助:
    内蒙古农业大学博士科研启动基金项目(BJ2014-4)

Time-varying Damage of Macro-and-micro Properties of Fly Ash Concrete in Corrosive Media

WANG Zong-xi, YAO Zhan-quan, HE Liang, WU Han-han, LIU Zi-mei   

  1. Water Conservancy and Civil Engineering College, Inner Mongolia Agricultural University, Hohhot 010018, China
  • Received:2020-06-08 Revised:2020-08-24 Online:2021-08-01 Published:2021-08-06

摘要: 以2 mol/L NH4Cl溶液为腐蚀介质,研究全浸泡条件下粉煤灰混凝土的耐蚀性能。溶蚀前,对粉煤灰混凝土进行气孔结构测试分析,研究溶蚀后的抗压强度损失以及溶蚀深度的变化幅度及变化规律,并采用核磁共振、场发射扫描电镜从机理上探讨不同粉煤灰掺量(0%、15%、30%、45%)混凝土溶蚀后的组织结构和孔隙的分布情况。研究表明:粉煤灰可细化混凝土内部孔隙,降低孔隙连通性并改善孔径分布,有效提高服役于水环境中混凝土的结构安全性和耐蚀性能。相对于普通混凝土溶蚀区域,粉煤灰混凝土溶蚀区域的内部生成了钙矾石晶体,说明钙矾石的生成可减轻溶蚀损伤。

关键词: 粉煤灰混凝土, 抗压强度, 时变损伤, 溶蚀深度, 孔隙结构, 微观形貌

Abstract: The corrosion resistance of fly ash concrete fully soaked in 2 mol/L NH4Cl solution as corrosive medium was studied in this paper. Before dissolution, the stomatal structure of fly ash concrete was tested and analyzed. The loss of compressive strength together with the change amplitude and change law of dissolution depth after the dissolution was investigated. Moreover, the structure and pore distribution of concrete after dissolution with different amounts of fly ash (0%, 15%, 30%, 45%) were examined via nuclear magnetic resonance and field emission scanning electron microscopy. Research results manifested that fly ash refined the internal pores of concrete, reduced pore connectivity and improved pore size distribution, which effectively enhanced the structural safety and corrosion resistance of concrete in water environment. Compared with ordinary concrete dissolution area, fly ash concrete dissolution area had ettringite crystals generated inside, indicating that the formation of ettringite can reduce corrosion damage.

Key words: fly ash concrete, compressive strength, time-varying damage, leaching depth, pore structure, micromorphology

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