为了研究膨胀剂对密闭钢管混凝土徐变及承载力的影响,基于CEB/ FIP 理论,采用数学方法,对钢管混凝土的核心混凝土的徐变进行理论计算,在试验构件尺寸不变的基础上,通过改变核心混凝土中膨胀剂的掺量,分析膨胀剂对钢管混凝土徐变的影响,最后对构件进行极限承载力试验。 得出采用CEB/ FIP 方法的理论计算值与试验值较为吻合,对钢管混凝土徐变和承载力,膨胀剂有最佳掺量,并且徐变对密闭钢管混凝土的极限承载力稍有提高。
In order to study the effects of expansion agent on the bearing capacity and creep of CFST, mathematical method is used to calculate the creep of core-concrete filled steel tube based on the theory of CEB/FIP. In the experiment, the size of experimental specimen remains unchanged and the effects of expansive agent on CFST are analyzed with variable amount of expansive agent in concrete. Finally, the ultimate bearing capacity of the components is tested. To the conclusion, the calculated value by CEB/FIP method is consistent with experimental value. There exists a best dosage of the expansive agent to the bearing capacity and creep and the creep can slightly improve the ultimate bearing capacity of the CFST.