- 目录
- 建筑石膏与胶凝材料
- 首页
拌合工艺对粉煤灰基纤维增强复合材料流动性与力学性能的影响
作者：徐艺珅1，曾国东1，周敏1，方杨1，李超1，高英力2
（1.佛山市交通科技有限公司，广东 佛山 528000；2.长沙理工大学 交通运输工程学院，湖南 长沙 410114）
摘要：以粉煤灰、水泥和硅灰为三元胶凝材料体系，混杂PVA纤维、改性PP纤维和碳酸钙晶须为纤维增韧媒介，制备了粉煤灰基纤维增强复合材料，研究了拌合工艺（包括投料顺序和搅拌时间）对复合材料的流动性和力学性能的影响。结果表明：相比于“湿拌+纤维后掺法”，“干拌+纤维先掺法”更有利于胶凝材料粉末与纤维的均匀分散，且拌合过程中阻力小，基体流动度高，早期抗折强度（7 d）最高提高了28.5%；充分的干拌时间为复合材料基体提供了良好的分散环境，可显著提高粉煤灰基纤维增强材料的早期抗折强度，但过长的搅拌时间会削弱纤维在基体中的密实填充效应和桥连效应，导致试件的早期抗折强度有所降低；最佳的拌合时间为干拌5 min、湿拌5 min、最后全拌6 min。
关键词：纤维增强；拌合工艺；流动性；力学性能
中图分类号：TU528.58 文献标识码：A 文章编号：1001-702X（2022）09-0139-05
Effect of mixing procedure on the fluidity and mechanical strength of the fly-ash based fiber reinforced cementitious materials
XU Yishen1，ZENG Guodong1，ZHOU Min1，FANG Yang1，LI Chao1，GAO Yingli2
（1.Foshan Transportation Science and Technology Co. Ltd.，Foshan 528000，China；
2.Changsha University of Science & Technology，School of Traffic and Transportation Engineering，Changsha 410114，China）
Abstract：The ternary cementitious materials of fly ash，cement，and silica fume，mixed with PVA fiber，modified PP fiber and calcium carbonate whisker as the fiber toughening medium，were used to prepare the fly ash-based fiber-reinforced composites，and the effects of the mixing process，including the feeding order and mixing time，on the fluidity and mechanical properties of the composites were investigated. Compared with "wet mix+fiber after mixing"，"dry mix+fiber first mixing" is more conducive to the uniform dispersion of cementitious material powders and fibers，and the low resistance during the mixing and high fluidity of the matrix is realized，then the early flexural strength （7 d） improved by up to 28.5%. Sufficient dry mixing time provides a good dispersion environment for the composite matrix，which can significantly improve the early flexural strength of the fly ash-based fiber- reinforced materials，but excessive mixing time will weaken the fiber in the matrix，in terms of the dense filling effect and bridging effect，resulting in the reduction of the early flexural strength of the specimens. The best mixing time is 5 min of dry mixing，5 min of wet mixing，and finally 6 min of full mixing.
Key words：fiber-reinforced，mixing process，fluidity，mechanical property