中南大学学报（自然科学版）2024，Vol.55Issue(4)：1374-1387,14.DOI:10.11817/j.issn.1672-7207.2024.04.012
多因素耦合的混凝土结构硫酸盐传输多尺度模拟分析
Multi-scale simulation analysis of sulfate transport in concrete structures coupled with multiple factors
摘要
Abstract
A multiscale simulation and analysis method for sulfate transport in concrete structures coupled with multiple factors was proposed.Based on Fick's second law and chemical reaction kinetics,a multi-factor coupled sulfate transport model was proposed,which simultaneously includes the ion concentration gradient effect,chemical reaction consumption considering ion activity,calcium dissolution,ettringite expansion and temperature.Firstly,the concrete structure was modeled as a homogeneous material,the sulfate transport law of homogeneous concrete structure was investigated from the macroscopic scale,and the transport model was verified in comparison with the experimental data.Subsequently,employing the Monte Carlo method and Fuller's grading curve,a stochastic aggregate concrete model was established to authentically reflect the randomness and heterogeneity of concrete.This model allows for the investigation of the characteristics of sulfate transport in concrete structures influenced by the random sizes and positions of aggregates at a mesoscopic scale.The results show that the mass fraction of sulfate ions in concrete significantly increases with greater external sulfate ion mass fractions,higher temperatures,and higher calcium ion concentrations in the pore solution.The shift in solid-liquid equilibrium due to calcium leaching has a more pronounced impact on the transport of sulfate ions than changes in the porosity of the concrete caused by leaching.Moreover,the sulfate transport model at the mesoscopic scale effectively demonstrates the randomness and unevenness in the distribution of sulfate ions caused by the randomness of aggregate sizes and positions.The presence of aggregates results in a higher accumulation of sulfate ions on the sides near the erosion boundary,while the sides of aggregates away from the erosion boundary have lower mass fraction of sulfate ions.关键词
硫酸盐传输/随机骨料混凝土/多尺度Key words
sulfate transport/random aggregate concrete/multiscale分类
建筑与水利引用本文复制引用
郭文华,吴彪,陈定市..多因素耦合的混凝土结构硫酸盐传输多尺度模拟分析[J].中南大学学报（自然科学版）,2024,55(4):1374-1387,14.基金项目
国家自然科学基金资助项目(52078489) （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)(Project(52078489)supported by National Natural Science Foundation of China （2023ZZTS0373）
Project(2023ZZTS0373)supported by the Fundamental Research Funds for the Central Universities of Central South University) （2023ZZTS0373）
