多因素作用下钢筋混凝土构件氯离子扩散系数模型.pdf

.ututu.com
第33卷第1期
土木建筑与环境工程
Vol 33 No
2011年2月
Journal of Civil, Architectural & Environmental Engineering
Feb,.2011
多因素作用下钢筋混凝土构件氯离子扩散系数模型
滕海文,舒正昌“,黄颖“,霍达
(北京工业大学a.建筑工程学院;b.城市与工程安全减灾省部共建教育部重点实验室,北京100124)
摘要:通过对钢筋混凝土氩离子侵蚀机理的分析,在Fick第二扩散定律基础上,建立了综合考虑
水灰比、湿度、时间、温度、混凝土材料对氣离子结合作用等多因素作用下的氯离子侵蚀模型,并给
出了考虑边界条件的侵蚀模型数学解。通过对长期现场暴露试验数据分析,验证了该侵蚀模型的
有效性和可靠性。与传统的Fick第二扩散定律模型对比并分析得:该模型不仅能反映结构实际受
氯盐侵蚀的发展趋势和混凝土不同深度处的氲离子浓度,而且能预測不同时期钢筋处的氟离子含
量和钢筋开始锈蚀时间。
关键词:侵蚀;扩散系数;多因素;钢舫混凝土构件
中图分类号:TU528.01文献标志码:A文章编号:1674-4764(201101-0012-05
Chloride Ion Diffusion Coefficient Model of R. C.
Elements under Multiple Factors
TENG Hai-wen, SHU Zheng-chang, HUANG Ying, HUO Da
(a. College of Architecture and Civil Engineering; b. Key Lab of Urban Security
and Disaster Engineering, MOE, Beijing University of Technology. Beijing 100124, P R. China)
Abstract: Based on the analysis of chloride ion-induced erosion mechanism of reinforced concrete and the
Fick, s second law, a multi-factor model of the chloride ion erosion is established. In this model, the
influences of watercement ratio, humidity, time, temperature, and chloride ion binding capacity of
concrete are taken into consideration, and the mathematic solution to the new model is provided by
considering the boundary conditions. The new model is verified by analyzing the long-term expose
experiment data. Compared with the traditional model of Ficks second law, the model can indicate the
development trend of the structure eroded by chloride and the chloride ion concentration in different depth
and at the same time, it can predicate the chlorine ion concentration on rebar surface in different corrosion
periods and the initiation corrosion time of reinforcement
Key words: erosion; diffusion coefficient; multiple factors; R. C
elcments
影响混凝土结构耐久性的因素中,钢筋锈蚀是2个主要因素,通常认为后者即氯离子侵蚀引起
最主要的原因之一,而钝化膜破坏是钢筋锈侠的“元的钢筋锈蚀最为直接、严重和普週
凶”。在无杂散电流环境中,混凝土中性化和钢筋表
混凝土结构在氯盐环境下的使用寿命取决于混
面有一定浓度的游离C是导致钢筋钝化膜破坏的凝土的氯离子渗透性能,而氯离子扩散系数是反映
收稿日期:2010-06-02
基金项目:国家自然科学基金资助项目(50808005);国家科技支撑计划项日(2006BAJI27B4);北京市自然科学基金重大
项目(8100001)
作者简介:滕海文(1974-),女,博士,副教授,主要从事结构耐久性分析、结构损伤识别与维修加固研究,(E-mail
tenghaiwen(@bjut.edu.cn