摘要
为提高碳纤维水泥基复合材料(CFRCC)的压敏性,研究了羟乙基纤维素(HEC)对CFRCC中短切碳纤维分散特征的影响,采用灵敏度系数法分别探究了不同HEC掺量和短切碳纤维掺量对CFRCC压敏性的影响规律,并根据电化学阻抗法和可蒸发水含量法分析了相应CFRCC的孔结构特征,然后采用SEM测试技术对CFRCC基体中短切碳纤维分散状况以及纤维与基体界面特征进行了深入观察。结果表明:HEC分散剂在CFRCC中的掺量为胶凝材料总质量的0.4%~0.6%时,可以使CFRCC具有良好力学性能的条件下发挥更好的压敏性;CFRCC基体水胶比在0.35时,短切碳纤维的分散效果最好。在相同水胶比条件下,随着短切碳纤维掺量的增加,CFRCC抗折强度均有不同程度的提高,而其抗压强度则逐渐降低。当短切碳纤维体积掺量为0.2%时,短切碳纤维在CFRCC基体中无互相搭接和成簇现象;综合考虑压敏性和力学性能,CFRCC中短切碳纤维的适宜掺量范围为0.2%~0.25%。
In order to improve the compression-sensitivity of CFRCC,the effect of hydroxyethyl cellulose(HEC)on the dispersion characteristics of short carbon fibers in CFRCC was studied,the influence of different HEC content and short carbon fiber content on CFRCC compression-sensitivity was explored by the sensitivity coefficient method,and the pore structure characteristics of the corresponding CFRCC were analyzed according to the electrochemical impedance method and the evaporation water content method,and then the dispersion status of the short carbon fibers in the CFRCC matrix and the interface characteristics between the fibers and the matrix were deeply observed by SEM testing technology.The results show that when the dosage HEC dispersant in CFRCC is 0.4%to 0.6%of the total mass of the cementitious material,it can make CFRCC exert better compression-sensitivity under the condition of enduring its good mechanical properties.When the water-binder ratio of the CFRCC matrix is 0.35,short carbon fiber has the best dispersion effect.Under the same water-binder ratio,with the increase of short carbon fiber content,the flexural strength of CFRCC increases to varying degrees,while the compressive strength decreased gradually.When the volume of short carbon fibers is 0.2%,short carbon fibers do not overlap and cluster with each other in the CFRCC matrix.Considering the compression-sensitivity and mechanical properties,the suitable content range of short carbon fibers in CFRCC is 0.2%to 0.25%.
作者
方思怡
巴明芳
许浩锋
张晨剑
谢嘉磊
王志豪
FANG Siyi;BA Mingfang;XU Haofeng;ZHANG Chenjian;XIE Jialei;WANG Zhihao(School of Civil&Environmental Engineering and Geography Science,Ningbo University,Ningbo 315211,Zhejiang,China;Collaborative Innovation Center of Coastal Urban Rail Transit,Ningbo University,Ningbo 315211,Zhejiang,China)
出处
《材料导报》
CSCD
北大核心
2023年第15期291-299,共9页
Materials Reports
基金
国家自然科学基金(51978346)
宁波大学滨海城市轨道交通协同创新中心开放基金项目(XT2021013)。
关键词
碳纤维水泥基复合材料
分散剂
压敏性
短切碳纤维
carbon fiber reinforced cement-based composites
dispersant
compression-sensitivity
short carbon fiber
