粉煤灰、MgO膨胀剂和减缩剂对面板混凝土抗裂性能的影响  

Effects of Fly Ash,MgO Expansive Agent and Shrinkage-reducing Admixture on the Crack Resistance of Face Slab Concrete

作　　者：张迪[1] 郭凡星 王磊 ZHANG Di;GUO Fan-xing;WANG Lei(Yellow River Conservancy Technology Institute,Kaifeng 475004,Henan Province,China;College of Materials Science and Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,Shaanxi Province,China)

机构地区：[1]黄河水利职业技术学院,河南开封475004 [2]西安建筑科技大学材料科学与工程学院,西安710055

出　　处：《中国农村水利水电》2021年第5期205-209,共5页China Rural Water and Hydropower

基　　金：国家自然科学基金项目(51409016)。

摘　　要：面板混凝土的抗裂性能对面板堆石坝的服役寿命具有较大影响。试验研究了掺粉煤灰、MgO膨胀剂和减缩剂的面板混凝土力学性能、干缩性能以及抗裂性能,并与基准混凝土进行了对比。结果表明:在混凝土中掺入20%粉煤灰有利于后期强度的提高,而掺6%MgO膨胀剂或1%减缩剂会降低各龄期的混凝土抗压强度、劈裂抗拉强度和极限拉伸值。掺加20%粉煤灰、6%MgO膨胀剂或1%减缩剂都在一定程度上降低了混凝土各龄期的干缩率并提高了混凝土的早期抗裂性能,其中掺6%MgO膨胀剂抑制混凝土干缩并改善混凝土抗裂性能的效果更佳。Crack resistance of concrete face slab is very important for the service life of concrete faced rockfill dam(CFRD).The effects of fly ash,MgO expansive agent and shrinkage-reducing admixture(SRA)on the mechanical properties,drying shrinkage and crack resistance of face slab concrete are studied and compared with the reference concrete.The results show that the addition of 20%fly ash(by weight of binder)enhances the strength of concrete at the late age.In contrast,the addition of 6%MgO expansive agent or 1%SRA reduces the compressive strength,splitting tensile strength and ultimate tensile to some degrees at various ages.The incorporation of 20%fly ash,6%MgO expansive agent and 1%SRA can reduce the dry shrinkage at various ages and improve the early crack resistance of concrete,while the incorporation of 6%MgO expansive agent is more conducive to inhibiting the shrinkage development and improving the crack resistance of concrete than the addition of 20%fly ash or 1%SRA.

关 键 词：面板混凝土 粉煤灰 膨胀剂 减缩剂 抗裂性 

分 类 号：TV431[水利工程—水工结构工程]