活性氧化镁对氯氧镁水泥收缩性能和抗折强度的影响

Influence of activated MgO on shrinkage and flexural strength of magnesium oxychloride cement

为了研究活性MgO对氯氧镁水泥收缩性能与抗折强度的影响,对不同活性MgO含量的MOC进行收缩率、抗折强度、水化产物组成以及显微结构进行了测试。结果表明,MOC试件的收缩率随MOC中活性MgO含量增加而增大,MOC收缩变形是由毛细孔水分蒸发与水泥硬化失水两方面综合作用的,活性MgO含量越高越容易引起试件失水收缩。此外,活性MgO含量高的MOC试件更有利于5相的形成,使水泥空间形成致密结晶结构,因而抗折强度相对更高。

In order to study the influence of activated MgO on the shrinkage and flexural strength of magnesium oxychloride cement(MOC),the MOC specimens with different amount of activated MgO were researched by measuring the change of length and using mechanics machine to test flexural strength,also the hydrate phase and microstructure of MOC specimens were observed by XRD and SEM in this paper.The results showed that the ratio of shrinkage and flexural strength increase with the amount of activated MgO,the mechanism of shrinkage was explained in two ways,evaporation of water and self-hardening dehydration,while high content of activated MgO excess moisture loss,leads to shrink.Moreover,the MOC specimens containing higher amount of activated MgO has higher flexural strength than others for it is beneficial to form more phase 5 and build up firm crystal microstructure,which is benefits the flexural strength of MOC.