复合纤维对混凝土抗裂性能的影响

由于复合纤维具有良好的力学性能,通过掺入一定比例的多壁碳纳米管/聚丙烯腈复合纤维制备具有抗裂性能的混凝土,使用WA-1000B型液压式万能试验机和PTS-E0系统分别对试件的力学性能和抗裂性能进行测试,并结合混凝土综合抗裂模型,对掺加量为1.2~2.1 kg/m3的4组混凝土的力学性能和抗裂性能进行研究.实验结果表明:复合纤维的掺入可以提高水泥混凝土强度40%左右,同时减少了表面裂缝的出现,混凝土的力学性能和抗裂性能随着复合纤维掺加量的增加呈现增强趋势,但复合纤维的工程用量需要综合考虑.

Influence of composite fiber on crack resistance of concrete

Composite fiber has good mechanical properties. The concrete with crack resistance is prepared by adding a certain proportion of multi-walled carbon nanotubes/polyacrylonitrile composite fiber. WA-10OOB universal hydraulic test- ing machine and PTS-E0 system are employed to test the mechanical properties and crack resistance of the concrete, re- spectively. Based on complex crack resistance model, the mechanical properties and crack resistance of four groups of concrete with fiber proportion of 1.2%-2.1% are compared with those of concrete without fiber. The results show that by adding composite fiber, the strength of cement concrete is increased by 40% and the surface crack is reduced. The me- chanical properties and crack resistance trend to increase with increasing of added content of composite fiber, while the usage amount of composite fiber in engineering project should be considered synthetically.