腐蚀疲劳作用下混凝土膨胀内应力分析  

Analysis of expansion internal stress of concrete under coupling action of corrosion and fatigue

作　　者：邢明亮[1] 王伯禹[2] 李华平 陈拴发[1] 

机构地区：[1]长安大学交通铺面材料教育部工程研究中心,陕西西安710064 [2]湖北省交通运输厅汉十高速公路管理处,湖北武汉430051 [3]珠海城建市政建设有限公司,广东珠海519002

出　　处：《长安大学学报（自然科学版）》2013年第2期22-26,37,共6页Journal of Chang’an University(Natural Science Edition)

基　　金：国家自然科学基金项目(50978031);中央高校基本科研业务费专项资金项目(CHD2011JC018)

摘　　要：为了研究交变荷载对硫酸盐侵蚀混凝土所产生膨胀内应力的影响,引入受交变荷载应力水平及加载频率影响的有效扩散系数,基于Fick第二定律,建立腐蚀与疲劳耦合作用下的扩散反应方程,并采用有限差分法进行求解;在混凝土单轴抗拉强度本构关系的基础上,由膨胀应变计算膨胀内应力,研究交变荷载应力水平、加载频率、外界硫酸盐浓度和水灰比对其膨胀内应力的影响,并应用灰色关联熵对各因素进行分析。结果表明:随交变荷载应力水平、加载频率、水灰比和外界硫酸盐浓度的增加,膨胀内应力产生以及达到极限抗拉强度的时间出现了不同程度的提前,其中,水灰比是影响膨胀内应力的最主要因素;在腐蚀疲劳工况中,混凝土满足设计要求的前提下宜采用较小的水灰比,以提高其耐久性。To study the impact of alternation load on expansion internal stress of the sulfate corro- sion concrete, the effective diffusion coefficient impacted by alternating stress level and loading frequency was introduced, diffusion reaction equation basing on Fick＇s second law under the cou- pling action of corrosion and fatigue, and the finite difference method was used to solve it. Based on constitutive relation of the uniaxial tensile strength of concrete, the expansion internal stress was calculated through expansion strain, the influence of alternating load stress level, loading frequency, the concentration of external sulfate and water-cement ratio on concrete expansion in- ternal stress was studied, and gray relational entropy was used to analyze various factors. The re- sults indicate that with increasing of the stress level of alternating load, loading frequency, water- cement ratio and external sulfate concentration, the time of generating expansion internal stress and achieving the ultimate tensile strength influencing factor is water-cement ratio. In the requirements, the smaller water-cement rable performance. 2 tabs, 5 figs, 9 refs. increases in varying degrees, corrosion fatigue condition, among which the main if concrete design meet ratio of concrete should be adopted to improve its du-

关 键 词：道路工程 混凝土 硫酸盐侵蚀 膨胀内应力 数值分析 

分 类 号：U416.224[交通运输工程—道路与铁道工程]