硫酸盐侵蚀下混凝土抗压承载力退化过程的数值分析  

Numerical Investigation on Degradation Process of Compressive Capacity of Concrete Subjected to Sulfate Attack

作　　者：马强[1] 左晓宝[1] 王佳林 殷光吉 汤玉娟[1] MA Qiang;ZUO Xiao-bao;WANG Jia-lin;YIN Guang-ji;TANG Yu-juan(Department of Civil Engineering, Nanjing University of Science ＆ Technology, Nanjing 210094, China)

机构地区：[1]南京理工大学土木工程系,江苏南京210094

出　　处：《土木工程与管理学报》2017年第6期146-152,共7页Journal of Civil Engineering and Management

基　　金：国家自然科学基金(51378262;51078186);江苏省自然科学基金(BK20141396)

摘　　要：针对硫酸盐侵蚀下混凝土结构的承载力退化问题,以混凝土柱为研究对象,利用Fick定律和化学反应动力学原理,给出了硫酸根离子在混凝土截面内的二维扩散反应模型;根据硫酸盐侵蚀混凝土的损伤机理及已有的硫酸盐侵蚀试验结果,获得了混凝土强度损伤程度与硫酸根离子浓度及侵蚀时间之间的关系;通过平截面假定,建立了考虑硫酸盐侵蚀影响的混凝土柱轴向抗压承载力时变模型及其数值计算方法,并将该模型的计算结果与已有硫酸盐侵蚀混凝土的试验结果进行对比分析,验证了该时变模型及数值计算方法的正确性;最后,利用所建立的模型,对一素混凝土柱中硫酸根离子传输、混凝土强度损伤和轴向抗压承载力退化过程进行了数值分析。This paper takes concrete column as an object for studying the degradation bearing capacity of concrete structures subjected to sulfate attack. Based on the Fick＇ chemical reaction kinetics, a two-dimensional diffusion-reaction equation of sulfate ion process of the s law and the in concrete is firstly suggested. Then, according to the damage mechanism of concrete caused by sulfate attack and the existing experimental results of the sulfate corrosion on concrete, the relationship between theconcrete damage degree and the sulfate ion concentrationand the corrosion time is presented. Next, using the plane section assumption, a computational model of the compressive capacity of concrete column in the process of sulfate attack is established, and its numerical solution is obtained by the fiber model and finite difference method. The calculation results of the model are compared with the experimental results of the existing sulfate attack concrete to verify the correctness of the time-varying model and numerical calculation method. Finally, numerical analysis of the sulfate ion diffusion in concrete, the material damage and the compressive capacitydegradationof concrete column is carried out.

关 键 词：硫酸盐侵蚀 混凝土 抗压承载力 退化 模型 

分 类 号：TU528[建筑科学—建筑技术科学]