Mesoscopic and stochastic analysis of chloride ion erosion in saturated concrete by numerical tests(PDF)
长安大学学报（自然科学版）[ISSN:1006-6977/CN:61-1281/TN]
- Issue:
- 2017年06期
- Page:
- 38-46
- Research Field:
- 桥梁与隧道工程
- Publishing date:
Info
- Title:
- Mesoscopic and stochastic analysis of chloride ion erosion in saturated concrete by numerical tests
- Author(s):
- HU Da-lin; CHEN Ding-shi; ZHANG Li-xing; CHEN Feng
- 1. Key Laboratory of Bridge Detection & Reinforcement Technology of Ministry of Transport, Chang’an University, Xi’an 710064, Shaanxi, China; 2. CCCC First Highway Consultants Co., Ltd., Xi’an 710061, Shaanxi, China; 3. Shaanxi Provincial Transport Planning Design and Research Institute, Xi’an 710065, Shaanxi, China
- Keywords:
- bridge engineering; concrete; numerical test; saturated state; chloride ion erosion; stochastic specimen; normal distribution
- PACS:
- U444
- DOI:
- -
- Abstract:
- To study the law of chloride ion erosion in saturated state concrete, firstly, based on Fick’s second law, the new diffusion equation was proposed on the basis of the former considering factors such as the deterioration of concrete, loading, effect of chloride binding capacity, temperature, relative humidity inside concrete, time dependence of chloride diffusion, effect of electrostatic field of ion and the new diffusion equation affecting the surface chloride concentration. Then aimed at the randomness of chloride erosion, a meso scale model of concrete was established, and the macro model of chloride erosion was combined with the mesoscopic stochastic concrete model, thus, a new method for the study of chloride ion erosion of concrete was proposed from stochastic and mesoscopic level. The corresponding software was programmed based on the platform of MATLAB, and stochastic concrete specimens could be generated with arbitrary aggregate content and meet different grading requirements. And the fig format graphics files generated by MATLAB could be converted into dxf format, so that the established stochastic concrete model could be called expediently by finite element softwares. Finally, the general law of chloride ion erosion in concrete was summarized with mathematical statistics and probability method by means of numerical tests of 105 stochastic concrete specimens. The results show that the material transport in meso level is strikingly different from the macro level both in concentration distribution and numerical value. The transmission of chloride ions in concrete has significant randomness. Chloride ions contents in concrete with the same aggregate content and depth are random variables. The transport of chloride ions is impeded remarkably by the aggregate. The transmission path of chloride ion in concrete is changed because of the aggregate. The chloride ions transfer around the aggregate. The distribution of chloride ions content in concrete at a certain depth approximately accords with the normal distribution.
Last Update: 2017-12-18