摘要
采用长期氯盐干湿循环的试验方法,探讨不同钢纤维体积掺量对UHPC氯离子传输性能的影响,分析表观氯离子扩散系数和表面氯离子浓度的时变规律。结果表明:(1)UHPC在干湿交替作用180 d后在2 mm处出现对流区,且内部氯离子浓度分布符合Fick第二定律;(2)钢纤维的掺入不影响对流区的产生,侵蚀早期UHPC的表观扩散系数会随着钢纤维体积掺量的增加而增加,随着龄期的增长而逐渐减缓;(3)表面氯离子浓度随着时间的增大趋于稳定,其发展规律符合指数模型。
Using a long-term chloride wet-dry cycling test method,the effects of different steel fiber volume fractions on the chloride ion transport properties of UHPC were investigated.The time-dependent variation of the apparent chloride diffusion coefficient and surface chloride concentration was analyzed.Results indicate that:(1)after 180 days of wet-dry cycles,a convection zone develops at a depth of 2 mm in UHPC,with the internal chloride ion concentration distribution following Fick s second law;(2)the addition of steel fibers does not alter the formation of the convection zone,while in the early stages of erosion,the apparent diffusion coefficient of UHPC increases with higher steel fiber volume fractions but gradually decreases with time;(3)the surface chloride concentration stabilizes over time,conforming to an exponential model.
出处
《福建建设科技》
2025年第2期53-56,共4页
Fujian Construction Science & Technology
关键词
超高性能混凝土
钢纤维
氯离子传输
氯离子表观扩散系数
ultra-high performance concrete
steel fiber
chloride transport
apparent chloride diffusion coefficient
