碳纳米管/钢纤维水泥基复合材料的力学性能分析

Mechanical Properties of Carbon Nanotubes/Steel Fiber Cement Composites

对多壁碳纳米管(MWCNTs)进行改性处理,研究钢纤维单掺、钢纤维与MWCNTs复掺两种情况对水泥基复合材料的力学性能影响,并利用扫描电镜进行微观结构分析。研究结果表明:掺入钢纤维能够显著提高水泥净浆材料的抗折和抗压强度,且抗折强度的提高幅度高于抗压强度;复掺钢纤维和碳纳米管的水泥净浆材料相对于纯水泥净浆力学性能的提升效果,比单掺碳纳米管水泥净浆的力学性能提升效果更好。MWCNTs和钢纤维在水泥基中均起到纤维锚固作用,能够从不同尺度上抑制材料内部裂缝的产生和发展,提高材料力学性能,但是碳纳米管分散不均匀会降低复掺对水泥基材料的力学性能提高效果。

Multi-walled carbon nanotubes(MWCNTs)were pretreated by modification before adding to cement paste.The effects of MWCNTs and steel fiber on the mechanical properties of cement-based composites were studied.The microstructure of the composites was analyzed by scanning electron microscopy(SEM).The results show that the flexural strength and compressive strength of cement paste can be improved significantly by adding steel fiber,and the flexural strength is improved more than the compressive strength.Compared with pure cement paste,the mechanical properties of the cement paste material mixed with both steel fibers and carbon nanotubes are improved better than those of the cement paste only mixed with the carbon nanotube.Both MWCNTs and steel fiber play a role of fiber anchoring in cement-based materials,which can inhibit the generation and development of internal cracks in materials from different scales and improve the mechanical properties of materials.However,the uneven dispersion of carbon nanotubes will reduce the improvement effect of mechanical properties of cement-based materials.