超高层混凝土建筑收缩徐变效应分析

Analysis on creep and shrinkage effects of high-rise concrete buildings

超高层混凝土建筑无法通过铰接、后安装等措施释放收缩、徐变效应导致的附加变形、附加内力。CEBFIP Model Code 90、CEB-FIP Model Code 2010与ACI209规范对混凝土收缩、徐变效应的计算公式不同,考虑的参数也不同,但计算方法类似。考虑混凝土构件的含钢率后,收缩、徐变效应会随着含钢率的增大而降低。超高层混凝土建筑可采用分段补偿法施工,将每一分段内各层竖向构件的施工预留长度之和在分段底层内进行补偿,以降低混凝土收缩、徐变效应导致的竖向构件变形差,确保结构安全。

Additional deformation and additional internal force of high-rise concrete buildings caused by shrinkage and creep effects will not be released easily by construction method.CEB-FIP Model Code 90,CEB-FIP Model Code 2010 and ACI209 specifications offered different formulas for calculating concrete shrinkage and creep effect,but methods are similar.Shrinkage and creep effects will be reduced with the increase of steel ratio of concrete member was taken into account.The segmented compensation method during the construction period can be used to reduce the displacement difference of vertical components of high-rise concrete buildings caused by shrinkage and creep effects.