轻烧氧化镁膨胀剂对水泥浆体自收缩的影响.pdf

新控主坑中中
中国科技核心期刊
轻氧化镁膨胀剂对水泥浆体
收缩的影响
张守治,王军伟2,刘加平,田倩
(1.高性能上木工程材料国家重点实验室,江苏省建筑科学研究院有限公司,江苏南京210008
2.中国铁道科学研院标准计量研究所,北京100081)
摘要;研究了轻烧氧化镁膨胀剂(0、3%、5%)和粉煤灰(O、30%、,45%)对水胶比为0.35約水泥浆体自收缩性能的影响规律,并
探讨了轻烧氧化镁膨胀剂和粉煤灰复合作用下对低水胶比水泥米体自收缩联合补偿的减缩协同效应。结果表明:轻烧氧化镁和粉
媒灰单独掺加时均能抑制水泥浆体的自收缩,二者复合双掺后对水泥浆体的自收缩抑制的幅度更大,表现出较好的减缩协同效应。
关键词:轻烧氧化镁;粉煤灰;水泥浆体;自收缩;减缩协同效应
中图分类号:1TUS28.042
文献标识码:A
文章编号:1001-702X(2013)04-0011-04
Autogenous shrinkage of cement paste containing light calcined magnesia expansive agent
ZHA NG Shouzhi, WANG hunuei', LIU Jiaping, TA N Qian
(1.State Key Iaboratory of High Performance Civil Engineering Materials
Jiangsu Academy of Building Science Co. Itd, Nanjing 210008, Jiangsu, China
2. Standards and Metrology Research Institute, China Academy of Railway Sciences, Beijing 100081, China)
Abstract: The influences of light calcined magnesia expansive agent with replacement percentages of 0, 3%, 5% and fly ash
with replacement percentages of 0, 30% and 45% on the autogenous shrinkage of cement paste with water-to-binder ratio of 0.35
were studicd. The effect of composite of light calined magnesia expansive agent and fly ash on autogenous shrinkage compensation
of cement paste with low waler-to binder ratio was discussed. The results show that both light calcined magnesia expansive agent
and fly ash reduce the autogenous shrinkage of cement paste. A synergistic effect on the autogenous shrinkage reduction was ob
served when the light calcined magnesia expansive agent and the fly ash were used together
Key words: light calcined magnesia; fly ash; cement paste; autogenous shrinkage; reduction synergistic effect
随着混凝土高效减水剂的发展,现代混凝土的发展越来越纹的产生,将使混凝土裂缝从内部向外部扩展,从而影响到混
趋于高性能化。混凝土高性能化的标志就是以低水胶比为特征凝土结构的安全性?。
的高强高耐久,而低水胶比带来的后果则使混凝土内部相对湿
轻烧氧化镁膨胀剂由于在密封绝湿环境下具有持续的自
度随水泥水化的进行而降低,造成自干燥,加剧自收缩。随着生体积徵膨胀,而被广泛应用于补偿大体积混凝土的温降收
自收缩的增大,混凝土内部产生微裂纹的几率增大,这种微裂缩。相比之下,将轻烧氧化镁膨胀剂用于补偿低水胶比混
凝士自收缩的研究不多,本文以低水胶比的水泥浆体为研究
基金项目:国家重点基础研究发展计划(973计划)资助项目
对象,考察轻烧氧化镁膨胀剂(0、3%、5%)和粉煤灰(0、30%、
(2010CB735801)
45%)对水胶比为0.35的水泥浆体自收缩性能的影响规律,并
“+二五”国家科技支撑计划资助项目(2011BAE27BO1-2):探讨了轻烧氧化镁膨胀剂和粉煤灰复合作用下对低水胶比水
“十二五家科技支撑计划资助项目(201BAE27B04-4)泥浆体自收缩联合补偿的减缩协同效应
收稿日期:2012-09-17
1试验
作者筒介:张守治,男,1982年生,安徽阜阳人,硕士。地址:江苏省南
京市江宁区万安西路59号苏博特研发中心,E- mail: zhangshouzhi1.1原材料
水泥:江南小野田PⅡ525水泥,标准稠度用水量28.7%,
NEW BUILDING MATERIALS