自密实混凝土早期自收缩及微观孔结构研究  

Study on Early Autogenous Shrinkage and Microcosmic Pore Distribution of Self-compacting Concrete

作　　者：杨玉红[1] 李悦[1] 杜修力[1] 

机构地区：[1]北京工业大学城市与工程安全减灾省部共建教育部重点实验室,北京100124

出　　处：《建筑材料学报》2010年第5期601-606,共6页Journal of Building Materials

基　　金：北京市科技新星计划项目(2005B09);北京市2005年留学人员科技活动择优项目

摘　　要：采用混凝土早期自收缩测量系统研究了粉煤灰掺量及水胶比对自密实混凝土早期自收缩的影响，并通过硬化混凝土孔隙结构测定仪和压汞仪研究了自密实混凝土的微观孔结构．结果表明：粉煤灰的掺入能降低自密实混凝土早期的自收缩，且随粉煤灰掺量的增加，减缩效果更为显著；随着水胶比的降低，自密实混凝土的自收缩逐渐增大；自密实混凝土早期自收缩与其微观孔结构关系密切，自密实混凝土自收缩主要是因孔径为0～50nm．的孔隙量的增加而造成的．By using a measuring system designed by authors for autogenous shrinkage of concrete, the in- fluences of fly ash＇s use level and water-binder ratio on the early autogenous shrinkage of self-compacting concrete（SCC） were studied. The concrete＇s microcosmic pore distribution was also studied by air bubble measurement and mercury intrusion porosimetry. The results show that the early autogenous shrinkage of SCC can be reduced by adding fly ash. With the increasing use level of fly ash, the early autogenous shrinkage is reduced. The early autogenous shrinkage is increased with the reduction of water-hinder ratio. The early autogenous shrinkage of SCC depende greatly on its microcosmic pore distribution. The pore with diameter of 0 - 50 nm has greatest influence on the early autogenous shrinkage of SCC.

关 键 词：自收缩 粉煤灰 水胶比 孔结构 

分 类 号：TU528[建筑科学—建筑技术科学]