氯盐侵蚀下铜矿渣混凝土高温后内部钢筋锈蚀规律  

Corrosion extents of steel bar in copper slag concrete after exposure to high temperature under chloride attack

作　　者：陈奇 公伟[1] 苗吉军[1] CHEN Qi;GONG Wei;MIAO Jijun(School of Civil Engineering,Qingdao University of Technology,Qingdao 266033,China)

机构地区：[1]青岛理工大学土木工程学院,青岛266033

出　　处：《复合材料学报》2022年第6期2875-2884,共10页Acta Materiae Compositae Sinica

基　　金：山东省自然科学基金项目(ZR2017MEE029);山东省“双一流”建设工程-土木。

摘　　要：为探究高温及铜矿渣细骨料对混凝土中钢筋锈蚀模式的影响规律,对不同铜矿渣置换率的混凝土试件进行高温试验,然后采用干湿循环浸泡法对试件进行人工加速氯离子侵蚀试验,并利用电化学方法测量自然电位值以监测混凝土内部钢筋的锈蚀情况,最后测量混凝土内部氯离子含量及钢筋锈蚀率。结果表明:自然电位法可以较好地反映试件内部钢筋的实际锈蚀情况;高温破坏了混凝土抗氯离子侵蚀性能,从而导致混凝土试件中的钢筋锈蚀程度随经历温度的升高而增大;此外,高温下铜矿渣自身较大的膨胀变形及冷却后与水泥净浆间不协调收缩的综合作用进一步破坏了混凝土微结构,使钢筋锈蚀率随着铜矿渣置换率的提高而增大;最后建立了氯盐侵蚀下铜矿渣混凝土高温后内部钢筋锈蚀深度拟合公式。In order to investigate the influence of high temperature and copper slag fine aggregate on corrosion mode of steel bar in concrete,high temperature test was carried out on concrete specimens with different copper slag replacing ratios,then the artificial accelerated chloride ion corrosion test was conducted on the specimens using dry-wet cycling immersion method,and the corrosion state of steel bars embedded in concrete was monitored by measuring the half-cell potential value using electrochemical method,the chloride ion content in concrete and corrosion rate of steel bar were also measured at last.The results show that the half-cell potential method well reflects the actual corrosion situation of steel bar in specimen.High temperature destroys the chloride ion penetration resistance performance of concrete,thus causing the corrosion degree of steel bar in concrete specimen increases with the increase of heating temperature.In addition,the combined effect of inherent larger expansion deformation of copper slag at high temperature and uncoordinated shrinkage between copper slag and cement paste after cooling furtherly destroys the microstructure of concrete,thus causing the corrosion rate of steel bar increases with the increase of copper slag replacing ratio.A fitting formula for corrosion depth of steel bar in copper slag concrete after exposure to high temperature under chloride attack was established at last.

关 键 词：铜矿渣混凝土 高温 氯盐侵蚀 钢筋锈蚀 自然电位 

分 类 号：TU375[建筑科学—结构工程]