不同暴露条件下海工混凝土耐久性几何效应分析  

GEOMETRIC EFFECT ANALYSIS OF CONCRETE STRUCTURES EXPOSED TO DIFFERENT MARINE CONDITIONS

作　　者：夏辉[1] 周新刚[1,2] 李克非[2] 

机构地区：[1]烟台大学土木工程学院,烟台264005 [2]清华大学土木工程系,北京100084

出　　处：《工程力学》2013年第9期227-233,共7页Engineering Mechanics

基　　金：国家科技支撑计划课题-跨海集群工程混凝土结构120年使用寿命关键技术项目(2011BAG07B04)

摘　　要：基于氯离子扩散传输机理,利用有限体积法(FVM)推导了二维矩形和圆形截面混凝土氯离子扩散传输离散方程。根据FVM的数值模拟计算结果,研究了暴露条件及混凝土组成材料对具有不同截面形状的混凝土构件中氯离子含量及使用寿命的影响。数值模拟计算表明,不仅暴露条件、混凝土组成材料等对海工混凝土结构的耐久性有重要影响,而且其影响程度与混凝土构件截面的几何形状有关,有比较明显的几何形状效应。圆形截面由于有近似的一维扩散传输特征,在相同条件下,混凝土中的氯离子含量小于矩形截面,其使用寿命比矩形截面的大,但两种截面的差别在不同暴露条件和混凝土组成材料时又有显著的不同,大气区以及掺矿渣时更为明显。Based on the transportation mechanism of chloride diffusion and mass conservation theorem in any finite control volumes of concrete, two dimensional differential diffusion equations are derived as discrete equations using Finite Volume Method （FVM）. The FVM can be used to perform numerical simulation of chloride ion penetration into concrete and life prediction of concrete structural members with rectangular and circular section exposed to marine environment. According to the results of numerical simulation, the influence of exposure conditions and material composition on the chloride content and service life of concrete members with different section shape is studied. The results indicates that the exposure conditions and material composition have great influence on the durability of marine concrete, while the degree of influence is related to the geometric section shape, and the geometric shape effect is pretty obvious. Because the boundary condition of circular section is similar to that of one dimensional shape, the chloride content in circular section is less than that in rectangular section, and the service life of concrete members with circular section is longer than that with rectangular section. However, the difference between the two geometric shapes varies significantly in different exposure conditions and material composition. And the most remarkable difference can be found in the atmospheric zone and adding slag as admixture.

关 键 词：混凝土结构 有限体积法(FVM) 数值模拟 氯离子含量 寿命预测 几何效应 

分 类 号：TU528.33[建筑科学—建筑技术科学]