钢筋非均匀锈蚀及剩余截面积分布模型  

Non-uniform corrosion and distribution models of residual cross-sectional areas of rebars

作　　者：刘晋宏 罗小勇[1] 肖烨 LIU Jinhong;LUO Xiaoyong;XIAO Ye(School of Civil Engineering,Central South University,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075

出　　处：《华中科技大学学报（自然科学版）》2021年第11期83-88,共6页Journal of Huazhong University of Science and Technology(Natural Science Edition)

基　　金：国家自然科学基金资助项目(U1361204)。

摘　　要：为研究钢筋锈损剩余截面积的随机性,对钢筋混凝土板进行半浸泡通电加速锈蚀试验以获取不同锈蚀率的钢筋,由三维激光扫描获得钢筋试件的三维几何模型和剩余截面积数据,采用正态分布、对数正态分布、韦布尔分布和耿贝尔分布模型对剩余截面积的概率分布进行量化,比较其拟合优度,并基于拟合的剩余截面积分布估算锈蚀钢筋变形.研究结果表明:平均锈蚀程度越高,钢筋锈蚀越不均匀,最小截面越薄弱;未锈蚀钢筋剩余截面积分布为单峰对称型,随锈蚀率增大其逐渐变为左偏分布,当平均锈蚀率大于20%时,部分试件的剩余截面积为多峰分布;对平均锈蚀率不大于20%的钢筋,韦布尔分布模型对其剩余截面积概率分布拟合效果最佳,可用于计算锈蚀钢筋剩余变形;对平均锈蚀率大于20%的钢筋,单峰分布模型拟合效果较差.To investigate the stochasticity of residual cross-sectional areas of corroded rebars,reinforced concrete slabs halfimmersed in the solution were corroded by accelerated experiment with impressing current,and geometric models and residual crosssections of rebars were obtained by three-dimensional laser scanning.Normal distribution,lognormal distribution,Weibull distribution and Gumbel distribution models were adopted to quantitatively evaluate the probability distribution of residual crosssections,and their goodness of fit were compared.Degraded deformation of corroded rebars was calculated based on the fitting probability distribution models of residual cress-sectional areas.Research results show that as corrosion degree increases,the corrosion becomes more uneven,and the minimum cross-section becomes weaker.The distribution of cross-sectional areas is unimodal and symmetrical for uncorroded rebars,and gradually becomes left-skewed as the corrosion degree increases.When the corrosion degree is greater than 20%,the residual cross-sections of some specimens follow multimodal distribution.The Weibull distribution models best fit the distribution of cross-sectional areas for rebars with corrosion degree not greater than 20%,which can be used to calculate the residual deformation of corroded rebars.While for rebars with corrosion degree greater than 20%,the unimodal distribution models could not work well.

关 键 词：锈蚀钢筋 非均匀锈蚀 三维激光扫描 剩余截面积 概率分布 

分 类 号：U444[建筑科学—桥梁与隧道工程] TU511.3[交通运输工程—道路与铁道工程]