水泥基材料细观结构导致的氯离子传输不确定性研究  

Study of mesostructure-induced uncertainties of chloride transport in cement-based materials

作　　者：陈定市 郭文华[1] CHEN Dingshi;GUO Wenhua(School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《中南大学学报(自然科学版)》2025年第1期156-172,共17页Journal of Central South University:Science and Technology

基　　金：国家自然科学基金资助项目(52078489);中南大学中央高校基本科研业务费专项资金资助项目(2023ZZTS0373)。

摘　　要：氯离子诱发的腐蚀是海洋环境和除冰盐环境钢筋混凝土结构性能退化和寿命衰减的主要原因。本文采用细观统计的方法对氯离子在水泥基材料中传输的时空变异性进行研究。基于不同体积分数的等效随机混凝土试件的氯离子质量分数细观统计结果,分析氯离子质量分数和扩散系数的概率分布类型和时空变化规律。在此基础上,根据细观统计分析得到的骨料特性参数与氯离子扩散系数之间的定量关系和Spearman相关性,提出氯离子扩散系数的细观概率框架,并结合多组试验数据建立考虑骨料体积分数和粒径的氯离子扩散系数预测模型。研究结果表明:氯离子在细观混凝土中的传输具有强烈的骨料粒径效应、骨料颗粒数效应和大骨料局部效应;氯离子质量分数和扩散系数均具有显著的空间和时间变异性;氯离子质量分数服从正态分布或对数正态分布,而扩散系数服从对数正态分布。研究成果可对钢筋混凝土结构的概率型氯离子传输和使用寿命预测提供参考。Chloride-induced corrosion is a principal cause of performance degradation and lifespan diminution in reinforced concrete structures within marine and de-icing salt environments.The spatiotemporal variability of chloride transport within cement-based materials was studied using a mesoscopic statistical method.Based on the mesoscopic statistical results of chloride transport in equivalent random concrete specimens with varying volume fractions,the probability distribution types and spatiotemporal variation patterns of chloride mass fraction and diffusion coefficients were analyzed.On this basis,a mesoscopic probabilistic framework for chloride diffusion coefficients was proposed based on the quantitative relationship and Spearman correlation between aggregate characteristics and the chloride diffusion coefficients,and a prediction model for chloride diffusion coefficients considering aggregate volume fraction and particle size was established with multiple sets of experimental data.The results show that the chloride transport in mesostructured concrete is significantly influenced by the effects of aggregate particle size,aggregate particle number,and the localized impact of large aggregates.The chloride mass fraction and diffusion coefficients show noteworthy spatiotemporal variability.Chloride mass fraction follows a normal or log-normal distribution,whereas diffusion coefficients conform to a log-normal distribution.The research provides instrumental reference in predicting the probabilistic chloride transport and service life of reinforced concrete structures.

关 键 词：混凝土 氯离子传输 概率模型 细观混凝土 随机特性 

分 类 号：TU528[建筑科学—建筑技术科学] U444[建筑科学—桥梁与隧道工程]