掺超细羰基铁粉的导电功能集料制备与性能

摘要

Conductive functional aggregate was prepared by mixing super fine carbonyl iron powder and clay powder together and calcining.XRD and SEM were used to investigate the mineral phases and microstructure of the aggregate.And the conductivity,porosity and water absorbing ratio of the aggregate,and its effect on conductive performance of carbon fiber reinforced concrete were studied.Results showed that super fine carbonyl iron powder can exist in ceramic matrix and act as conductive phase,and tunnel transition of electron can occur among the micro particles and forms electric current.In this experiment,6.5vol％ content of iron powder is the percolation threshold for forming the conductive network.Content of iron powder has effect on porosity and water absorbing ratio of the aggregate by affecting the formation of liquid phase in the calcination process.Compared to common non-conductive aggregate,conductive aggregate obviously decreased the resistivity of concrete at the same carbon fiber content.%将超细羰基铁粉按一定比例与经粉磨处理的粘土粉等原材料混合,压制成型后经煅烧、破碎制备得到了导电功能集料;采用XRD、SEM等测试手段研究了导电功能集料的矿物相及微观结构,同时对其导电性能、气孔率和吸水率,以及其对碳纤维混凝土导电性能所起的作用等进行了研究.结果表明,超细羰基铁粉可作为导电相存在于陶质基体之中,电子通过隧道跃迁效应而在铁粉微粒间形成电流,6.5％的体积掺量是形成导电通路的逾渗阈值;超细羰基铁粉在煅烧过程中通过影响液相的形成而影响集料的气孔率和吸水率等;在同样碳纤维掺量下,导电功能集料与普通不导电集料相比可显著降低混凝土的体积电阻率.