氯盐腐蚀钢绞线蚀坑几何尺寸的分布特征  

Distributing character of size of pits on steel strands corroded by chloride

作　　者：李富民[1,2] 袁迎曙[1] 

机构地区：[1]中国矿业大学深部岩土力学与地下工程国家重点实验室,江苏徐州221008 [2]华南理工大学亚热带建筑科学国家重点实验室,广东广州510640

出　　处：《煤炭学报》2011年第11期1826-1831,共6页Journal of China Coal Society

基　　金：国家自然科学基金资助项目(51178454);江苏省自然科学基金资助项目(BK2011222);华南理工大学亚热带建筑科学国家重点实验室开放基金资助项目(2010KB03)

摘　　要：从氯盐腐蚀预应力混凝土梁试件中获取腐蚀钢绞线试样,观察并抽象了蚀坑的几何形状;然后,从其中截取4段不同腐蚀率的钢绞线试样进行蚀坑宽度、深度及长度的量取和统计,研究了蚀坑几何尺寸的分布特征。结果表明:钢绞线钢丝的蚀坑几何形状可抽象为椭球形和马鞍形2种典型形状;随腐蚀率的增大,蚀坑密度总体上有所增大;坑宽近似服从正态分布,坑长较好地服从对数正态分布,而坑深分布则难于服从常规的传统分布模式,由此可知,同一腐蚀率钢绞线上相对浅、短、中宽的蚀坑分布较多;坑宽分布不具备分形特征,坑深和坑长分布则显示了典型的分形特征,二者的分布分维均随腐蚀率的增大而增大,由此表明,随腐蚀率的增大,坑深和坑长均显示了渐趋接近的分布特征。综合分析认为,随腐蚀率的增大,钢绞线上各蚀坑的尺寸渐趋接近,其中坑深和坑长偏聚于各自的较小值附近,而坑宽则偏聚于其中等值附近。With the corroded steel strands from some prestressed concrete beams contaminated with salt,the configuration of the pits were studied.And then,4 samples of corroded steel strands with different corrosion rates were obtained,and the width,depth and length of the pits were measured and accounted,and the distributing character of pits size were studied.The results show that the configuration of the pits include 2 typical modes such as spheroidicity and saddle.With the developing of corrosion,the pits become denser and denser.The width of pits subjects to normal distribution approximatively and the length of pits subjects to logarithmic normal distribution preferably,but the depth of pits does not subject to the conventional distribution modes.So,on one corroded steel strand,the shallow and short and moderate wide pits are in the majority.The fractal characteristic does not show in the distribution of pits width but show in the distribution of pits depth and length,and both of the fractal dimensions increase with the corrosion development.So,with the increase of corrosion rate,the distribution of both pits depth and pits length are trend to approach.The compositive analyse indicates that the size of pits on steel strands is trend to approach with the increase of corrosion rate.The pits depth and pits length approach to the relative minor values,but the pits width approach to the relative moderate values.

关 键 词：钢绞线腐蚀 蚀坑形状 分布特征 预应力结构 耐久性 

分 类 号：TU511.3[建筑科学—建筑技术科学] TU378.1