MgO混凝土自生体积变形与压蒸膨胀值的相关性

Correlation between autogenous volume change of concrete mixed with MgO and pressure-braise expansion value

进行了高掺MgO水泥净浆、砂浆和混凝土试体的压蒸安定性和体积变形试验研究,并分析了净浆、砂浆和混凝土自生体积变形的基本特性和规律。揭示了压蒸膨胀值及试验变化过程以及超掺MgO时的突变现象与净浆、砂浆和混凝土自生体积变形之间存在着极其密切的相关关系,即存在相同的直线变化过程和相类似的急剧增大的变化规律。研究还表明,压蒸安定性试验方法是鉴定外掺MgO水泥混凝土体积长期安定性的唯一的有效方法,为确定安全的MgO允许最大极限掺量提供了试验依据。

Experimental study was performed on the pressure-braise stability and volume change of cement grout, cement mortar and concrete samples mixed with high-content MgO. The characteristics and rules of pressure-braise expansion and autogenous volume changes of the samples as well as their sudden changes due to over-mixing of MgO were analyzed. It is concluded that the autogenous volume changes of the three kinds of samples follow the same linear rules and undergo the similar sharp increase. It is also showed that the pressure-braise stability experimental method is the only effective way to evaluate the long-term stability of concrete mixed with MgO, providing an experimental basis for determination of the maximum amount of MgO to be mixed.