自然条件下MgO混凝土体积变形  

Volume deformation of concrete with MgO expansive agents exposed to natural environment

作　　者：涂永恒 邓敏[1,2] 莫立武 黄晓军[1] 王卫彪 TU Yongheng;DENG Min;MO Liwu;HUANG Xiaojun;WANG Weibiao(State Key Laboratory of Materials-Oriented Chemical Engineering,College of Materials Science and Engineering,Nanjing Tech University,Nanjing 210009,China;Jiangsu National Synergetic Innovation Center for Advanced Materials,Nanjing 210009,China)

机构地区：[1]南京工业大学材料科学与工程学院材料化学工程国家重点实验室,江苏南京210009 [2]江苏先进生物与化学制造协同创新中心,江苏南京210009

出　　处：《南京工业大学学报（自然科学版）》2018年第6期20-25,共6页Journal of Nanjing Tech University(Natural Science Edition)

基　　金：国家自然科学基金重点项目(51461135003);国家科技支撑计划(2011BAE27B01)

摘　　要：MgO混凝土安定性评定多采用较高的养护温度,但高温养护下混凝土中MgO水化产生的膨胀一般大于自然环境条件下的膨胀,加速试验结果不能真正反映工程实际情况。本文采用与实际工程相同的配合比在春季和夏季成型三级配混凝土,在自然条件下进行养护,测定混凝土试件的变形过程和混凝土MgO膨胀剂(MEA)中MgO的水化过程。结果表明:在自然养护条件下,环境温度改变对混凝土体积变形有重要影响,混凝土试件总变形随气温的升高或降低呈膨胀或收缩趋势;浇筑时的环境温度越高,混凝土试件的MEA中MgO水化速率越快,混凝土试件膨胀发展越快,不掺MEA混凝土的自身体积收缩越大; MEA中MgO水化产生的膨胀随着水化程度的提高而增大,掺量越高,膨胀速率越快。High temperature curing is generally used to evaluate the soundness of MgO concrete.However,the elevated temperature may overestimated the expansion due to hydration of periclase in MgO expansive agents.The MgO concrete cast in spring and summer was exposed to natural environment in Nanjing to investigate the deformation due to hydration of periclase in MgO expansive agents(MEA).Results showed that the environmental temperature was one of the main factors that affected the deformation of MgO concrete in natural environment.The expansion from hydration of periclase in concrete with MgO expansive agents casted in summer developed faster than that casted in spring.The higher the MgO expansion agents content was,the larger the expansion from hydration of periclase in concrete with MgO expansive agents.

关 键 词：混凝土 MGO膨胀剂 体积变形 自然环境 

分 类 号：TU528[建筑科学—建筑技术科学]