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Experimental study on long-term behavior of RC columns subjected to sustained eccentric load

  • Kim, Chang-Soo (School of Architecture, Seoul National University of Science and Technology) ;
  • Gong, Yu (School of Civil Engineering, Shandong Jianzhu University, Shandong Provincial Key Laboratory of Appraisal and Retrofitting in Building Structures) ;
  • Zhang, Xin (School of Civil Engineering, Shandong Jianzhu University, Shandong Provincial Key Laboratory of Appraisal and Retrofitting in Building Structures) ;
  • Hwang, Hyeon-Jong (School of Architecture, Konkuk University)
  • Received : 2019.07.25
  • Accepted : 2020.02.13
  • Published : 2020.03.25
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Abstract

To investigate the long-term behavior of eccentrically loaded RC columns, which are more realistic in practice than concentrically loaded RC columns, long-term eccentric loading tests were conducted for 10 RC columns. Test parameters included concrete compressive strength, reinforcement ratio, bar yield strength, eccentricity ratio, slenderness ratio, and loading pattern. Test results showed that the strain and curvature of the columns increased with time, and concrete forces were gradually transferred to longitudinal bars due to the creep and shrinkage of concrete. The long-term behavior of the columns varied with the test parameters, and long-term effects were more pronounced in the case of using the lower strength concrete, lower strength steel, lower bar ratio, fewer loading-step, higher eccentricity ratio, and higher slenderness ratio. However, in all the columns, no longitudinal bars were yielded under service loads at the final measuring day. Meanwhile, the numerical analysis modeling using the ultimate creep coefficient and ultimate shrinkage strain measured from cylinder tests gave quite good predictions for the behavior of the columns.

Keywords

Acknowledgement

Supported by : National Natural Science Foundation of China

This research was supported by grants from the National Natural Science Foundation of China (Research Fund for International Young Scientists, Grant No. 51650110498 and 51750410691) and the Research Program funded by the SeoulTech (Seoul National University of Science and Technology), and the authors are grateful to the authority for their supports.

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