白云石粉细度对胶砂强度及干缩的影响  

Influence of different-size dolomite powders on mechanical strength and dry shrinkage of cement paste

作　　者：周钰沦 刘振新 郑永超[1,2] 李润丰 李沙 罗紫隆 ZHOU Yulun;LIU Zhenxin;ZHENG Yongchao;LI Runfeng;LI Sha;LUO Zilong(Beijing Building Materials Academy of Sciences Research,Beijing 100041,China;Solid Waste Reuse for Building Materials State Key Laboratory,Beijing 100041,China;Beijing Key Laboratory of Energy Saving and Waste Resource Utilization Technology in Cement and Concrete,Beijing 102403,China)

机构地区：[1]北京建筑材料科学研究总院有限公司,北京100041 [2]固废资源化利用与节能建材国家重点实验室,北京100041 [3]水泥混凝土节能利废技术北京市重点实验室,北京102403

出　　处：《混凝土》2022年第11期129-132,共4页Concrete

摘　　要：二次粉磨白云岩加工砂石骨料过程中风选出的石粉至不同的细度,并通过试验探究白云石粉细度对其活性指数及胶砂干缩的影响。结果证明,通过对风选石粉进行二次粉磨,白云石粉的粒度降低,比表面积增加。当白云石粉比表面积超过400 m^(2)/kg时,其活性会有一定增长。但比表面积持续增长至650 m^(2)/kg时,石粉活性并不会随之增长,且胶砂的干缩率会随着石粉比表面积的增加而增加。另外,添加未进行二次粉磨的风选石粉可以有效降低胶砂干缩率。Through secondary grinding the stone powders which was selected from the sandstone aggregate manufacture by using dolomite as raw material,the effect of different-size dolomite powders on mechanical strength and dry shrinkage of cement paste were studied.The result shows that the size of dolomite powders decrease and specific surface area increase followed by the secondary grinding to dolomite stone powders.When the specific surface area of dolomite powders is over 400 m^(2)/kg,the activity of dolomite powders will present an increase.But the activity of dolomite powders will be constant,and dry shrinkage of cement paste will keep increasing,if the specific surface area of dolomite powders is up to 650 m^(2)/kg.Besides,adding stone powders without the secondary grinding can effectively decrease the dry shrinkage of cement paste.

关 键 词：风选石粉 二次粉磨 活性指数 干缩率 

分 类 号：TU528.01[建筑科学—建筑技术科学]