基于不同还原铁粉掺量的混凝土电磁屏蔽及吸波特性  

Electromagnetic shielding and baud absorption properties of concrete based on different content of reduced iron powder

作　　者：李新换 LI Xinhuan(Qinghai University for Nationalities,Xining 810007,China)

机构地区：[1]青海民族大学,青海西宁810007

出　　处：《混凝土》2021年第11期85-88,92,共5页Concrete

基　　金：天津大学—青海民族大学合作项目(2015XZS-0029)。

摘　　要：建筑工程材料的电磁防护能力对于信息安全日趋重要,常规混凝土无法达到电磁屏蔽性能,而钢纤维或碳纤维混凝土无法兼顾宽频电磁波的屏蔽和吸波能力。为解决这一问题,利用还原铁粉(Fe3O4)作为掺料,制备一种新型电磁屏蔽混凝土,并设计基于端口法和弓架法的电磁波反射率和透射率试验,定量评价了不同掺量水平和厚度条件下混凝土试件对于电池波的屏蔽和吸波特性。结果如下:首先,当加入还原铁粉后显著提升其材料的吸波能力,但是铁粉掺量对于反射率影响不大;其次,当掺量超过200 kg/m^(3)时,试样受谐振特性影响反而降低其透射率;通过对比分析,当掺量200 kg/m^(3),混凝土板厚度20 mm时,试样处10 GHz以下的电磁辐射环境中获得较好的屏蔽和吸收性能;10~15 GHz的电磁环境中,20、40 mm厚的混凝土板电磁防护性能相当;当频率高于15 GHz时,采用40 mm厚混凝土在电磁屏蔽和吸收特性上更优。该混凝土材料试样在电磁屏蔽性能上均有显著提高,具有一定宽频吸波性能,以期为电磁波防护工程建筑材料的研究提供一定参考和借鉴。Conventional concrete cannot achieve electromagnetic shielding performance,while steel fiber or carbon fiber concrete cannot take into account the shielding and absorbing ability of broadband electromagnetic waves.To solve these problem,it uses reduced iron powder(Fe3O4)as a preparation of concrete admixture,including port and arch method based on the quantitative evaluation of reflectivity and transmissivity of the specimens,test the level and the thickness of wave shielding and absorbing potter for batteries.The test results are as follows,first,when reduced iron powder is added,it significantly doubles the absorbing capacity of the material,but the content of iron powder has little effect on the reflectivity.Secondly,when the mixing amount exceeds 200 kg/cm^(3),the resonance characteristics of the sample will reduce its transmittance.Through comparative analysis,when the mixing amount is 200 kg/cm^(3) and the concrete plate thickness is 20 mm,better shielding and absorption properties are obtained in the electromagnetic radiation environment below 10 GHz at the sample.In the electromagnetic environment of 10~15 GHz,the electromagnetic protection performance of 20 mm and 40 mm thick concrete plate is similar.When the frequency is higher than 15 GHz,40 mm thick concrete is better in electromagnetic shielding and absorption characteristics.

关 键 词：电磁屏蔽 混凝土 还原铁粉 

分 类 号：TU528.041[建筑科学—建筑技术科学]