If reinforced concrete columns and walls in high-rise buildings are subjected to axial load for a sustained duration, long-term lateral deformation (or curvature) as well as axial shortening increase over time due to the creep and shrinkage of concrete. In the present study, sustained load tests were performed to evaluate the time-dependent axial shortening and lateral displacement occurring in eccentrically loaded columns. A test set-up using post-tensioning steel rods was introduced for the sustained loading with or without eccentricity. The test results showed that the lateral displacement as well as the axial shortening increased over the sustained duration but the increasing rate of the long-term deformations rapidly decreased with increasing time. The time-dependent axial shortening and lateral displacement increasing with time were predicted by using the age-adjusted effective modulus method based on the creep and shrinkage models of ACI 209. The predictions agreed well with the test results.

中文翻译：

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偏心受力钢筋混凝土柱的瞬态变形

如果高层建筑中的钢筋混凝土柱和墙持续承受轴向荷载，由于混凝土的徐变和收缩，长期的横向变形（或曲率）以及轴向缩短会随着时间的推移而增加。在本研究中，进行了持续载荷试验以评估偏心载荷柱中发生的与时间相关的轴向缩短和横向位移。引入了使用后张钢棒的测试装置，用于在有或没有偏心的情况下持续加载。试验结果表明，横向位移和轴向缩短随着持续时间的增加而增加，但长期变形的增加率随着时间的增加而迅速下降。