摘要
本工作采用不同标准安定性评价试验方法,系统开展了不同活性MgO膨胀剂(MEA)的安定性试验。结果表明:随着MEA掺量增加,混凝土膨胀率增大;随着MEA活性降低,其极限掺量逐渐变小;不同检测方法的MEA极限掺量存在较大差异。水泥净浆试饼法和雷氏夹法不适用于评价MEA在实际混凝土结构中的体积安定性。MEA安定性试验评价方法的极限掺量从大到小为混凝土压蒸法、高温养护法、砂浆压蒸法。采用混凝土压蒸法时,MEA-80s、MEA-120s、MEA-160s、MEA-210s的极限掺量分别为14%、7%、8%、7%。高温养护法不能使MEA完全水化,混凝土评价方法使用的混凝土与工程用混凝土实际状态更为接近。建议采用混凝土压蒸法作为MEA的极限掺量评价方法,但压蒸试验条件仍需进一步探索完善。
In this work,different standard soundness evaluation test methods were used to systematically carry out the soundness test of different active MgO expansion agent(MEA).The results showed that the expansion rate increased with the increase of MEA content,that the limit dosage gradually decreases with the decrease of MEA activity,and that there are great differences in the limit content of MEA among different detection methods.The cement paste cake method and the Ray's clamp method are not suitable for evaluating the volume stability of MEA in actual concrete structures.The limit content of MEA stability test evaluation method from large to small is concrete autoclave method>high temperature curing method>mortar autoclaving method.With concrete autoclave method,the limit contents of MEA⁃80s,MEA⁃120s,MEA⁃160s and MEA⁃210s is 14%,7%,8%and 7%,respectively.The high temperature curing method cannot completely hydrate MEA.The concrete used in the concrete evaluation method is closer to that of the actual state of engineering concrete.The concrete autoclaving method is recommended as the MEA limit content evaluation method,but the autopilot test conditions still need to be further explored and improved.
作者
段星泽
夏瑞杰
张宏泽
卢晓琳
李伟
DUAN Xingze;XIA Ruijie;ZHANG Hongze;LU Xiaolin;LI Wei(Sino-Sina Building Materials Co.,Ltd.,Zhengzhou 450100,China)
出处
《材料导报》
CSCD
北大核心
2023年第S02期183-187,共5页
Materials Reports
关键词
MGO膨胀剂
活性
安定性
极限掺量
压蒸
MgO expansive agent
active
soundness
limit dosage
autoclave
