摘要
超微气流粉碎机制备的再生微粉既有胶凝活性,又能有效控制粉体粒径分布。利用再生微粉取代部分水泥制备泡沫混凝土,创新性地将再生微粉的化学胶凝性和粉体粒径可控导致的物理增强效应结合起来实现泡沫混凝土强度的提高和成本的降低。经过优化实验确定泡沫的体积掺量为75%,超微气流粉碎机制备的再生微粉粒径分布在10~60μm之间。研究结果表明:再生微粉替代水泥有利于泡沫混凝土后期强度的提高。当再生微粉的掺入量为10%时,泡沫混凝土28 d抗压强度增强效果最优,其抗压强度达到3.09 MPa,相比纯泡沫混凝土提高了11.6%。通过进一步研究,所制备的复合泡沫混凝土强度变化原因在于:超微气流制备的再生微粉粒径主要集中在26μm左右,32μm以下的颗粒累积分布达到85%,而水泥中3~32μm颗粒含量对水泥的28 d强度起关键作用,此粒度再生微粉的掺入调节了体系的颗粒级配比,使得体系粒度分布于26μm左右的比例有所提高,优化了泡沫混凝土的骨架部分填充效果,从而提高了其抗压性能。
The recycled fine powder prepared with ultra-micro jet mill have both hydration activity,but also effectively control the particle size distribution.The recycled fine powder was used instead of some cement to prepare foamed concrete.Which innovatively combining the chemical gelling properties and the physical strengthening effects of recycled fine powders can be controlled by the particle size of the powders.It can improve the compressive strength of foamed concrete while reducing the cost.After optimization experiments,the optimum adding volume fraction was found to be 75%,and the optimum particle size of recycled fine powder prepared with ultra-micro jet mill is 10-60μm.The results show that the replacement of some cement with recycled fine powder is beneficial to the improvement of the compressive strength of foam concrete in the later period.When the mixing amount of recycled powder was 10%,the as-prepared foamed concrete showed the highest compressive strength of 3.09 MPa,which was 11.6%higher than that without recycled powder.The reason for the change of the compressive strength of the composite foam concrete according to further study is that the particle size of the recycled powder which prepared with ultra-micro jet mill.These recycled powder is mainly concentrated at about 26μm while the cumulative distribution of the particles under 32μm reaches 85%.The 3-32μm particles content of the cement plays a key role to 28 d compressive strength.The particle size of the recycled powder adjust the particle size distribution ratio in the whole system which the system of particle size distribution in the proportion of about 26μm has been increased so that the foam concrete skeleton filling effect is optimizing,and its compressive strength got increasing.
作者
张松
李如燕
董祥
张兰
李智雄
ZHANG Song;LI Ru-yan;DONG Xiang;ZHANG Lan;LI Zhi-xiong(School of Materials Science and Engineering,Kunming University of Science and Technology,Kunming 650093,China;National Engineering Research Center of Waste Resource Recovery,Kunming University of Science and Technology,Kunming 650093,China)
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2018年第9期2948-2953,共6页
Bulletin of the Chinese Ceramic Society
基金
国家重点研发计划(2017YFC0703302)
云南省创新团队计划开发项目(2016HC017)
科技部重点研发计划项目(KKQW201828002)
省级人培项目(KKSY201228079)
关键词
泡沫混凝土
再生微粉
粒度分布
抗压强度
foamed concrete
recycled powder
particle size distribution
compressive strength
