【摘要】 为探讨混凝土在不同环境因素下的抗氯离子渗透性能变化规律及机理,开展了三种类型混凝土分别在标准养护、干湿循环、冻融循环和碳化条件下的试验研究,测试了混凝土氯离子扩散系数、碳化深度及微观孔隙参数,探讨了混凝土抗碳化与抗氯离子渗透性之间的关系,并引入"混凝土孔隙曲折度"的概念进行了分析。结果表明,混凝土氯离子扩散系数与孔隙曲折度之间具有良好的负相关关系,不同环境因素对混凝土抗氯离子渗透性的影响不同,主要与孔隙曲折度对不同作用的反应不同有关。标准养护、干湿循环和碳化均可以提高孔隙曲折度,但冻融循环会降低孔隙曲折度。此外,矿物掺合料的掺入可以细化孔隙结构,提高混凝土孔隙曲折度,从而提高其抗渗性。更多还原

【Abstract】 To investigate the mechanism and the changes of chloride ion penetration of concrete under the action of different environmental factors, tests of chloride diffusion coefficient, carbonation depth and microcosmic pore structure parameters of three kinds of concrete under the condition of standard curing, dry-wet cycles, freeze-thaw cycles and carbonation were executed respectively in this paper.The dialectical relationship between carbonation resistance and chloride ion penetration of concrete was discussed.Meanwhile, the concept of "concrete pore sinuosity" was introduced.The results showed that, there is a good linear relationship between chloride diffusion coeffi cient and concrete pore sinuosity, different environmental factors have different influence on the chloride ion penetration of concrete,which is mainly related to pore sinuosity, and pore sinuosity varies with different actions.Standard curing, dry-wet cycles and carbonation can improve the pore sinuosity, while, freeze-thaw cycles can reduce the pore sinuosity.In addition, the incorporation of mineral admixtures can refine the pore structure and improve the pore sinuosity of concrete, so as to improve its impermeability.更多还原