外掺MgO混凝土自生体积变形反正切曲线模型参数计算式的改进

Improved Formula for Calculating Parameters of Arctangent CurveModel for Autogenous Volume Deformation of MgO-admixed Concrete

根据近年来MgO混凝土研究与应用的新发现,对外掺MgO混凝土自生体积变形反正切曲线模型的参数计算式进行改进,将外掺MgO混凝土在龄期90 d的自生体积膨胀量特征值ε90改进为以混凝土在龄期180 d的自生体积膨胀量ε180为特征值。结果表明:利用改进后的参数计算式计算的外掺MgO混凝土自生体积变形,在龄期150 d以后的拟合值与实测值更加接近,偏差率一般为2%~7%,甚至<1%;极限膨胀量减少4×10^-6~7×10^-6,与实际也更加接近。改进的计算式可供广大工程技术人员和科研人员参考。

The formula for calculating parameters of arctangent curve model for the autogenous volume deformation of MgO-admixed concrete is improved based on the new findings and applications of MgO-admixed concrete in recent years.The eigenvalue(ε90)of the autogenous volume expansive deformation of MgO-admixed concrete at age 90 d is revised as that at age 180 d(ε180).The autogenous volume deformation of MgO-admixed concrete calculated by the improved formula is closer to the measured value after the age of 150 d,with a deviation rate around 2%-7%or even less than 1%and the ultimate expansion reducing by 4×10^-6-7×10^-6,which is also closer to the reality.