• Journal of the Korea Concrete Institute
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• v.13 no.3
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• pp.261-267
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• 2001

The objective of this experimental study is to find the allowable level of axial load to give the proper flexural ductility according to the yield strength of lateral ties, and the distribution and amount of longitudinal bars used in confined high-strength concrete columns. Twelve concrete columns with a 20 cm square section and 80 cm high were tested under hi-axial loads. It was observed that the ductility tends to be improved at the axial loads not less than 0.4f$\_$ck/A$\_$g/. The utilization of high-strength ties in accordance with the ACI 318-99 can cause the brittle failure due to the wide tie spacing. Under the high level of axial loads not less than 0.4f$\_$ck/A$\_$g/. it is necessary for the buckling prevention of the longitudinal bars and the proper ductility improvement to use the high-strength ties with the consideration of the volumetric ratio and confinement type of the lateral ties, and the distribution of the longitudinal bars.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.3
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• pp.114-120
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• 2017

In this paper, the effect of the masonry infill walls on the seismic performance of the reinforced concrete(RC) frames with non-seismic details was evaluated through the static test of an masonry infilled RC frame sub-assemblage with non-seismic details of real size, and comparison with the test results of the RC frame sub-assemblage with non-seismic details. As the test results, lots of cracks occurred on the surface of the entire frame due to the compression of the masonry infilled wall, and the beam-column joint finally collapsed with the expansion of the shear crack and buckling(exposure) of the reinforcement. On the other hand, the stiffness of the shear force-story drift relationship decreased due to the wall sliding crack and column flexural cracks, and the strength finally decreased by around 60% of the maximum strength. The damage that concentrated on the upper and lower parts of columns was dispersed in the entire frame such as columns, a beam, and beam-column joints due to the wall, and the specimen was finally collapsed by expansion of the shear crack of the joint, not the shear crack of the column. Also, the stiffness of RC frame increased by 12.42 times and the yield strength by 3.63 times, while the story drift at maximum strength decreased by 0.18 times.