磷酸盐水泥碳纤维复合材料的导电性能研究∗

摘要

以高掺量粉煤灰磷酸盐水泥为基体,短切碳纤维为功能材料,制备出了磷酸盐水泥碳纤维复合材料(PCFC),同时制备了碳纤维硅酸盐基复合材料(CFRC),并利用压力试验机、交流电桥和SEM对二者的基本力学性能、导电性能及内部碳纤维分布进行了对比研究.此外还考察了碳纤维掺量、龄期对 PCFC 导电性能的影响.结果表明,PCFC相比CFRC在同等碳纤维掺量的情况下力学增强效果更好、导电性能更为优越；机理分析表明PCFC中存在二次“渗流”现象,而CFRC试体中则没有.SEM照片显示碳纤维掺量较高时,PCFC中的碳纤维分散得更好；龄期实验结果表明,当碳纤维掺量超过1．4％时,龄期对 PCFC 的导电性影响较小,具有良好的导电稳定性.%A comparative study on mechanical and electrical properties of both phosphate cement carbon fiber composites (PCFC)and carbon fiber reinforced cement composites (CFRC)were studied in this paper.The PCFC sample was prepared by using phosphate cement with high volume of fly ash as matrix,while the CFRC sample was prepared by using Portland cement as matrix.The same short cut carbon fiber was used in the both cement composites samples as the conductive components.The results showed that comparing with CFRC, PCFC has both higher electrical conductivity and mechanical properties,it is also easy to be prepared when they have same carbon fiber content.Mechanism analysis showed that there is a secondary percolation in PCFC sam-ples,but there is no the phenomenon in CFRC.By SEM image analysis,the results showed the distribution of carbon fibers in PCFC is more uniform than that of CFRC when the both cement composites contain a high car-bon fiber content.The aging time test results indictedd that when carbon fiber dosage is higher than 1 .4wt%, aging time has a little effect on electrical conductivity of PCFC,which means it has an excellent stability in elec-trical property.