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硅酸盐通报 ›› 2021, Vol. 40 ›› Issue (11): 3593-3600.

• 水泥混凝土 • 上一篇    下一篇

基于随机细观骨料的钢筋表面氯离子浓度概率分布研究

陈宣东1,2, 荣华3, 梁秒梦1,2, 虞爱平1,2, 明阳1,2   

  1. 1.桂林理工大学土木与建筑工程学院,桂林 541004;
    2.桂林理工大学,广西建筑新能源与节能重点实验室,桂林 541004;
    3.中冶建筑研究总院有限公司,北京 100082
  • 收稿日期:2021-05-14 修回日期:2021-07-13 出版日期:2021-11-15 发布日期:2021-12-08
  • 通讯作者: 明阳,工程师。E-mail: 574081667@qq.com
  • 作者简介:陈宣东(1990—),男,讲师。主要从事新型混凝土材料及结构耐久性方面的研究。E-mail:6616051@glut.edu.cn
  • 基金资助:
    广西自然科学基金(2020GXNSFBA297034);广西重点研发计划(桂科AB19259008);广西建筑新能源与节能重点实验室基金(桂科能19-J-21-4,8,30)

Probability Distribution of Chloride Ion Concentration on Surface of Reinforcing Bar Based on Random Meso-Aggregate

CHEN Xuandong1,2, RONG Hua3, LIANG Miaomeng1,2, YU Aiping1,2, MING Yang1,2   

  1. 1. College of Civil and Architecture Engineering, Guilin University of Technology, Guilin 541004, China;
    2. Guangxi Key Laboratory of New Energy and Building Energy Saving, Guilin University of Technology, Guilin 541004, China;
    3. Central Research Institute of Building and Construction, Beijing 100082, China
  • Received:2021-05-14 Revised:2021-07-13 Online:2021-11-15 Published:2021-12-08

摘要: 氯盐侵蚀诱发钢筋锈蚀是导致钢筋混凝土结构耐久性失效的主要因素之一。研究钢筋表面氯离子浓度概率分布对于预测海洋工程的服役性能具有十分重要的意义。通过引入随机厚度的界面过渡区,建立了包含骨料、界面过渡区以及砂浆的三相混凝土细观模型。在此基础上,结合氯离子扩散理论,建立了氯离子扩散细观数值模型。研究结果表明,骨料对氯离子的扩散具有阻碍作用,增加了氯离子的扩散路径。通过对6 000个钢筋表面氯离子浓度的模拟结果进行统计分析,发现:当骨料率为40%(体积分数)时,钢筋表面氯离子浓度呈双峰分布;当骨料率小于40%时,钢筋表面氯离子浓度近似呈正态分布;随着骨料率的增加,钢筋表面氯离子浓度不断减小,变异系数不断增大。

关键词: 钢筋混凝土, 氯离子侵蚀, 数值模拟, 概率分布, 细观混凝土, 界面过渡区

Abstract: Chloride ion erosion is one of the main factors leading to the durability failure of reinforced concrete (RC) structures. Thus, the study of the probability distribution of chloride ion concentration on the surface of reinforcing bar is of great significance to predict the service performance of marine engineering. By introducing the interface transition zone (ITZ) of random thickness, a concrete meso-model including aggregate, ITZ and mortar was established. Based on the theory of chloride ion diffusion, a meso-numerical model of chloride ion diffusion was established. The results show that the aggregate hinders the chloride ion diffusion and increases the chloride ion diffusion path. According to the statistical analysis of the chloride ion concentration on the surface of reinforcing bar surface by simulated 6 000 groups chloride ion diffusion, when the volume fraction of aggregate ratio is 40%, the chloride ion concentration on the reinforcing bar surface has a bimodal distribution and when aggregate ratio is lower than 40%, the chloride ion concentration on the reinforcing bar surface has a normal distribution. With the increase of aggregate ratio, the chloride iron concentration decreases and the coefficient of variation increases.

Key words: reinforced concrete, chloride ion erosion, numerical simulation, probability distribution, meso-concrete, interface transition zone

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