粉煤灰高强轻骨料混凝土早期自收缩及抗裂性试验研究  

Study on Early Autogenous Shrinkage and Crack Resistance of Fly Ash High-strength Lightweight Aggregate Concrete

作　　者：高英力[1] 龙杰[1] 刘赫[1] 李友云[1] 

机构地区：[1]长沙理工大学交通运输工程学院,长沙410114

出　　处：《硅酸盐通报》2013年第6期1151-1156,共6页Bulletin of the Chinese Ceramic Society

基　　金：国家自然科学基金(11072041);高等学校博士学科点专项科研基金(20104316120001);湖南省教育厅资助科研项目(11A005)联合资助

摘　　要：掺入不同细度的粉煤灰等量取代水泥10%～30%,制备了粉煤灰高强轻骨料混凝土,采用自行设计试验和椭圆环法试验分别研究了早期自收缩变形和抗裂性能,并与基准样进行了对比分析。结果表明:随粉煤灰的掺入,混凝土早期自收缩得到抑制,且随粉煤灰掺量的增加,自收缩随之减小,粉煤灰细度越高,减缩效果越明显;而在低水胶比条件下,水胶比越低,自收缩增大越显著;另外,骨料的预湿状态对自收缩影响较大,未预湿轻骨料显著增加了早期自收缩变形。椭圆环抗裂性试验表明,粉煤灰的掺入显著改善了轻骨料混凝土抗裂性能,且粉煤灰细度越高,早期抗裂性能增强越显著。因此,在实际工程中,粉煤灰的掺入可作为减小高强轻骨料混凝土早期自收缩和提高抗裂性能的技术手段。Cement has been equivalent replaced by 10%-30% fly ash of different fineness, and fly ash high-strength lightweight aggregate concrete have been prepared. And then the early autogenous shrinkage and crack resistance of concrete have been researched by self-designed test and elliptical ring test, comparing with that of the reference lightweight aggregate concrete. The test results show that the early water-binder ratio, the early autogenous reducing. Moreover, pre-wetting degree of shrinkage shrinkage increases significantly with the water-binder ratio lightweight aggregate has a great effect on the early autogenous , which is increased markedly with the addition of not pre-wetting hghtweight aggregate Elliptical ring test results indicated that the addition of fly ash can significantly improve crack resistance which is enhanced with the fineness of fly ash increasing. Therefore, in practical engineering, the addition of fly ash might be a technical means for early autogenous shrinkage reducing and crack resistance enhancing of lightweight aggregate concrete.

关 键 词：粉煤灰 轻骨料混凝土 自收缩 抗裂性 

分 类 号：TU528[建筑科学—建筑技术科学]