摘要
稻壳灰的颗粒粒径对其火山灰活性和稻壳灰混凝土的性能影响显著。为获得粉磨稻壳灰的颗粒特征变化规律,开展了不同粉磨时间、不同存放时间稻壳灰比表面积和粒径分布试验研究。研究结果表明:原状稻壳灰呈蜂窝状多孔结构,导致其具有超高活性;随着粉磨时间的增加,稻壳灰的比表面积非线性增大并趋于稳定,细颗粒逐渐增多,粗颗粒相应减少;稻壳灰的粉磨过程分为快速粉磨和缓慢粉磨阶段,中粒径D50在快速粉磨阶段迅速下降,而后缓缓降低直至平稳;稻壳灰粉磨后短期存放和长期存放均出现了颗粒团聚现象,短期存放较长期存放的团聚更为明显;粉磨过程引起的静电库仑力、范德华力和极大表面能是稻壳灰粉磨后颗粒团聚的诱因。
The pozzolanic activity of rice husk ash （RHA） and performance of RHA concrete is remarkably effected by particle size of RHA.For finding the rule of particle characteristics of grinding RHA, specific surface area and particle size distribution of RHA are studied with different grinding time and storage time.The following results are acquired by experiment.First,honeycomb porous structure of original RHA results in its high activity.Secondly, with the increase of grinding time, specific surface area of RHA increase nonlinearly and stabilize finally, meanwhile fine particles increase gradually and coarse particles decrease accordingly.Thirdly, grinding process is divided into rapid grinding stage and slow grinding stage.Particle size of D50 drops quickly in rapid grinding stage,and then slowly lower until , agglomeration phenomenon of RHA is found in short-term and long-term storage after grinding,but the phenomenon is more obvious in short-term storage.At last, static coulomb force,Van der Waals＇ force and the huge surface energy are appeared in grinding process and can lead to agglomeration of RHA particles after grinding.
出处
《混凝土》
CAS
北大核心
2017年第9期89-92,共4页
Concrete
基金
江苏省政策引导类计划(产学研合作)项目(BY2016061-12)
江苏省建设系统科技项目(2015ZD01)
江苏省建设系统科技项目(2016ZD29)
国家级大学生创新训练项目(201611049007Z)
关键词
稻壳灰
粉磨
比表面积
粒径分布
团聚
rice husk ash
grinding
specific surface area
particle size distribution
agglomeration
