• Journal of the Korea Concrete Institute
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• v.16 no.2 s.80
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• pp.249-260
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• 2004

The longitudinal steel connection of reinforced concrete bridge column is sometimes practically unavoidable, however the current Korean bridge design specifications have no special provisions about lap-splices of longitudinal steel. This paper reports experimental results of a research program investigating the seismic performance of circular RC bridge columns with respect to longitudinal steel connection detailing. Twenty-one circular column specimens were tested under quasi-static test. The columns with the entire longitudinal steel lap-spliced within plastic hinge region show relatively sudden strength degradation and low ductility than the columns with continuous longitudinal steel and the columns with half of longitudinal steel lap-spliced. However, the seismic performance of the column with mechanically connected longitudinal steel is similar to that of the column with continuous longitudinal steel. The final objectives of this study are to suggest appropriate longitudinal reinforcement connection details for the limited ductility design concept and to provide quantitative reference data and tendency for performance or damage assessment based on the performance levels such as cracking, yielding, collapse, etc. Ultimate displacement/drift ratio, displacement ductility, response modification factor, equivalent viscous damping ratio, residual deformation index, and effective stiffness are investigated and discussed in this paper.

• Journal of the Korea Concrete Institute
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• v.16 no.1 s.79
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• pp.111-124
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• 2004

This research is a part of a research program to verify the seismic performance of circular reinforced concrete bridge columns with respect to longitudinal steel connection details under cyclic lateral load. A total of 21 column specimens were constructed and tested. Main variables in this test program were longitudinal steel connection details(continuous, lap-spliced, and mechanically connected), confinement steel ratio, and axial force ratio, etc. The test results of the columns with different longitudinal steel connection details showed different failure mode, strength degradation, and seismic performance. From the quasi-static test, it was found that the columns with all longitudinal reinforcement lap-spliced showed significantly reduced ductility. However, seismic performance of the columns with half of longitudinal reinforcement lap-spliced showed limited ductility but much more ductile behaviour than the columns with all longitudinal reinforcement lap-spliced. It was also found that the seismic performance, failure mode and strength degradation of columns with mechanical connected longitudinal reinforcement were similar to those of columns with continuous longitudinal reinforcement.