机制砂中石粉对不同强度等级混凝土性能的影响研究  

Effect of microfines in manufactured sand on properties of various strength grade concretes

作　　者：李北星[1] 周明凯[1] 蔡基伟[1] 王稷良[1] 

机构地区：[1]武汉理工大学硅酸盐材料工程教育部重点实验室,湖北武汉430072

出　　处：《混凝土》2008年第7期51-54,57,共5页Concrete

基　　金：西部交通建设科技项目(200331881106)

摘　　要：机制砂生产中不可避免地产生一定数量的粒径小于75μm的石粉颗粒。针对国家标准GB/T14684—2001《建筑用砂》对强度等级低于C30、C30～C60、高于C60的混凝土用机制砂石粉含量限值分别为7%、5%、3%的规定,试验研究了超过国标规定上限的石粉含量分别对C30、C60、C80机制砂混凝土工作性、强度、干缩及氯离子扩散系数、抗冻等性能的影响,据此提出了混凝土用机制砂石粉含量限值可以进一步放宽的建议。Microfines with particle size being less than 75 μm are inevitably existed in manufactured sand.According to GB/T 14684-2001 of the Chinese National Standard of Sand for Building,micro fine content in manufactured sand used in concretes graded less C30,between C30 and C60, and higher than C60 is limited to the level of 3%, 5% and 7%, respectively.The results of studies on the C30, C60 and C80 concretes prepared from manufactured sands with above the specified limits of microfine content by GB/T 14684-2001 are presentee.In addition to the workability and strength of concretes, drying shrinkage, chloride diffusion coefficient as well as freezing and thawing resistance were determined.Hereby, it was put forward that the limits ofmicrofines content ifi manufactured sand for purposes of concretes can be broaden.

关 键 词：机制砂 石粉含量限值 混凝土 强度 

分 类 号：TU528.041[建筑科学—建筑技术科学]