电磁屏蔽石墨混凝土电导率实验研究

石墨混凝土具有耐酸碱、成本低、性能稳定等优点。针对电导率是材料电磁屏蔽性能的重要影响参数,以获得最佳导电性能为方向设计了石墨混凝土的探索性制备方案,研究了其配合比对混凝土电导率性能的影响,采用四针电极法考察石墨混凝土的导电性能。实验结果表明,石墨混凝土中电导率存在不均匀性,其中粗颗粒石墨混凝土比细颗粒石墨混凝土具有更好的导电性能,其值约0．8 S/cm,表现出较好的性能一致性,为工程应用提供了条件。增加20%导电镍粉,对导电性能有改善,但水灰比较大。掺碳纤维石墨混凝土样品,针对石墨质量分数71%,相对石墨掺入碳纤维2%,电导率值由0．8 S/cm降为0．17 S/cm。其中材料的多孔性是材料导电性降低的主要因素。

Experimental Study on Conductance of Electromagnetic Shielding Graphite Concrete

Graphite concrete has the advantages of acid and alkali resistance,low cost and performance stability. Aimed at best conductance,a series of experiments of conduct graphite concrete are designed.The effect of ratio to its conduct property is studied.Four-pin electrode method is adopted to view conductance of graphite concrete.The experimental result shows that asymmetry exists in conductance of graphite concrete.Coarse graphite concrete conduces a better conductance than fine graphite concrete,the conductance is about 0.8S/cm,puts up a good consistence of conductance,and offers a condition for engineering application.With 20% electric Ni powder added,the conductance is improved,but more water is needed.Adding 2% carbon fibre to graphite content,whose weight fraction is 71%,the conductance is dropped from 0.8 S/cm to 0.17S/cm. The porosity is the chief factor for the depress.