碳纳米纤维改性水泥基材料的变形及抗裂性能

Deformation Properties and Crack Resistance of Carbon Nanofiber Modified Cement-Based Materials

摘要:

用超声波分散和表面修饰法将碳纳米纤维（CNFs）分散到水泥基材料中，制备了CNFs改性水泥基材料，研究了其变形及抗裂性能.结果表明：CNFs能抑制水泥净浆的自收缩和干燥收缩，且显著延缓水泥砂浆的开裂时间；当CNFs掺量为0.05%时，CNFs改性水泥砂浆的开裂时间较空白组延长了48.5%；CNFs在水泥基材料中产生的桥连和拔出效应，延缓了裂纹的扩展，从而减少了CNFs改性水泥砂浆的收缩变形，提高了材料的抗裂性能.

Abstract:

Carbon nanofibers （CNFs） were dispersed in the cement-based materials by ultrasonic dispersion and surface modification to prepare the carbon nanofibers modified cement-based materials. The deformation properties and crack resistance of CNFs modified cement-based materials were studied. The results show that CNFs can inhibit the autogenous shrinkage and drying shrinkage of cement paste， and significantly delay the cracking time of cement mortar. When the mass content of CNFs is 0.05%， the cracking time of CNFs modified cement mortar is 48.5% longer than that of the control group. The bridging and pull-out effects of CNFs in cement-based materials delay crack growth， thus reduce the shrinkage deformation of CNFs modified cement mortar and improve the crack resistance of the materials.