硫酸盐侵蚀下混凝土细观模型及参数表征
Mesoscopic Model and Parameter Characterization of Concrete Under Sulfate Attack
刘新荣 1陈海 1庄炀 1周小涵 1肖宇2
作者信息
- 1. 重庆大学土木工程学院,重庆 400045
- 2. 重庆城投基础设施建设有限公司,重庆 400010
- 折叠
摘要
硫酸盐侵蚀是导致混凝土损伤劣化的主要因素之一,其中预测硫酸根离子在混凝土中的时空分布是研究混凝土损伤劣化的基础.相比于宏观模型,细观模型更能反映硫酸根离子在混凝土中的实际运移规律,但存在建模复杂、计算时间漫长等问题.将混凝土看作由水泥砂浆、界面层、粗骨料、宏观缺陷组成的四项复合材料,构建了混凝土二维细观模型,进而研究对比宏、细观模型对数值模拟的影响,并定义细观参数使宏观模型达到细观模型的模拟效果.结果表明:1)细观模型随机性对硫酸根离子扩散的影响可以通过取多组模型的平均值消除;2)含石量的增加伴随着侵蚀深度加深和同一位置处硫酸根离子浓度降低,且随着深度的增加,这种现象更加明显;3)细观参数随含石量的增加而增大.
Abstract
Sulfate attack is one of the main factors leading to the damage and deterioration of concrete.The prediction of the temporal and spatial distribution of sulfate ions in concrete is the basis of studying the dam-age and deterioration of concrete.Compared with the macroscopic model,the mesoscopic model can better reflect the actual migration law of sulfate ion in concrete,but there are some problems such as complex modeling and long calculation time.In this paper,concrete was regarded as four composite materials com-posed of cement mortar,interfacial layer,coarse aggregate and macro defects,and a two-dimensional me-soscopic model of concrete was constructed.Then,the effects of macro and mesoscopic models on numeri-cal simulation were studied and compared,and mesoscopic parameters were defined to make the macro-scopic model achieve the simulation effect of the mesoscopic model.The results showed that:1)the influ-ence of mesoscopic model randomness on sulfate ion diffusion could be eliminated by taking the average val-ue of multiple models;2)the increase of stone content was accompanied by the deepening of erosion depth and the decrease of sulfate ion concentration at the same location,and this phenomenon was more obvious with the increase of depth;3)the mesoscopic parameters increased with the increase of stone content.
关键词
硫酸根侵蚀/细观模型/数值模拟/含石量/细观参数Key words
sulfate attack/mesoscopic model/numerical simulation/stone content/mesoscopic parameter引用本文复制引用
出版年
2024
NETL
NSTL
万方数据