摘要
碳纤维增强水泥(CFRC)有很高的应变敏感性,在钢筋外均匀地包裹一层CFRC,并埋入普通混凝土中,当钢筋锈蚀体积膨胀时,对CFRC来讲,就如受有内压的圆筒埋入无限大弹性体中。通过监测CFRC的电阻变化可了解钢筋的锈蚀及其发展。据此,将CFRC制成内径为16mm壁厚为10mm的圆筒(包括内、外电极),24小时候后脱模并埋入边长为150mm的立方块中,再过24小时候后脱模并养护,28天后测试。根据钢筋锈胀的机理利用静态爆破剂的膨胀性和时效性来快速模拟钢筋锈蚀所产生的膨胀效应,采用静态爆破剂模拟钢筋的锈蚀产物,通过爆破剂的膨胀模拟锈蚀产物的体积膨胀作用,通过爆破剂的膨胀力的增大过程模拟钢筋锈蚀的发展过程。实验表明:利用CFRC包裹钢筋来监测钢筋锈蚀的方法灵敏度高,且可以进行定量估算。
Carbon fiber reinforced cement (CFRC) has high strain sensibility. If the rebar is bundled uniformly by a layer of CFRC and embedded in plain concrete, the CFRC likes an internally loaded cylinder embedded in an infinity elastic body when the rebar expands. The corrosion of the rebar and its propagation process can be known by monitoring the change of resistance of CFRC. We made a hollow cylinder with 16mm inner radius and 36mm outer radius (inner and outer electrode included), the specimen was de-molded and embedded into a plain concrete cube(150mm×150mm×150mm) after 24 hours. After another 24 hours, the specimen was de-molded again and cured at the same time and then measured after 28 days. Based on the mechanism of volume expansion of the corroded rebar, the expansible effect of the corroded rebar was simulated rapidly by the expansibility and time effect of static dynamite agent. The corrosion outcome was simulated by static dynamite agent and the volume expansion caused by corrosion outcome was simulated by expanding force of dynamite agent, whose increase was employed to simulate the progress of rebar′s corrosion. Experimental results reveal that this way to monitor the rebar′s corrosion by bundling it with CFRC is sensitive and the rebar′s corrosion condition can be estimated quantitatively.
出处
《实验力学》
CSCD
北大核心
2004年第2期206-210,共5页
Journal of Experimental Mechanics
基金
国家自然科学基金重点资助项目(50238040)
关键词
碳纤维增强水泥
压敏性
钢筋
锈胀
CFRC
compression sensitivity
rebar
corrosion expansion
