An experimental device was designed to measure the expansive stress of compacted MEA and that of cement pastes containing MEA under restraint condition.The content of periclase was analyzed by Xray diffraction and the hydration degree of periclase was calculated.Results indicated that the expansive stress of the compacted MEA-23 and MEA-46 hydrated for 22d were 38.9MPa and 62.7MPa,respectively.The expansive stresses of cement pastes containing MEA increased with the increasing content of MEA,the activity index of MEA and the hydration degree of periclase.The shrinkage stress of cement pastes without MEA cured for 63d was 1.3MPa,the expansive stress of cement pastes containing 12％ MEA-23 and MEA-46 cured for 63d were 1.8MPa and 3.0MPa,respectively.%本文研制了一套膨胀应力测试装置,并以此为基础测试了约束条件下MgO膨胀剂(MEA)压实体和掺MgO膨胀剂水泥浆体中水化产生的膨胀应力;采用X射线衍射法定量分析了MgO的含量,并计算MgO的水化程度.结果表明:活性指数为23 s和46 s的MgO膨胀剂压实体水化22d产生的膨胀应力分别为38.9MPa和62.7MPa;掺水泥浆体的膨胀应力随MEA掺量增大、MEA活性指数提高和MgO水化程度增加而增大,不掺MgO膨胀剂的水泥浆体63 d时的收缩应力为1.3MPa,掺12％活性指数为23s和46s的MgO膨胀剂水泥浆体在63 d时的膨胀应力分别为1.8MPa和3.0MPa.
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