ZEMCH 2019 International Conference Proceedings April.2020 | Page 163
(a)H-F
(b) KSS-5
(c) KSS-7
(d) KSS-12
Figure 5. Plastic Hinge Region of specimens at failure
4. Dscussion of test results
Ductility and energy dissipation capacity of the columns were experimentally investigated in this
study. The maximum lateral load, drift angle at yielding, ultimate drift angle, ductility ratio (μ) and
energy dissipation capacity for each specimen are given in 4. The ductility ratio (μ) was taken as the
ratio of ultimate drift angle to drift at yield (Δ u /Δ y ). Where drift angle corresponding to 85% of
maximum lateral load was taken as ultimate story drift. The energy dissipation capacity was calculated
by considering the area of the lateral force and drift‐angle relationship.
Test results showed that although the KSS specimens were designed with 27% less lateral
reinforcement than the H‐F specimens, the energy dissipation capability as well as member ductility
were increased because of spiral type transverse reinforcement configuration. Results also demonstrate
that the lateral confinement in KSS specimens was improved as the yield strength of spiral
reinforcement was increased.
Specimens
H‐F
KSS‐5
KSS‐7
KSS‐12
Yield of specimens
Drift angle
Py
(kN)
(%)
399
1.4
Table 4. Test results
After Peak 85%
Load
Drift
(kN)
angle
357
4.0%
Ductility
2.9 Energy
dissipation
(mm 2 )
260,166 -416 -1.2 431 350 4.0% 3.3 268,016 Flexural
-409 -1.1 425 356 3.0% 2.7 144,471 Flexural
-418 -1.0 427 362 4.0% 4.0 279,163 Flexural
Peak load
(kN)
445
V 85 /V u
Failure
modes
Flexural
5. Conclusions
In this study, experiments were conducted to evaluated the transverse confinement performance
of RC columns using newly developed spiral type transverse reinforcement and compared with
existing hoop reinforcement arrangement. Test results showed that specimens with spiral
reinforcement showed better performance than specimens with conventional hoops. Even though the
members with spiral arrangement had 27% less amount of transverse reinforcement than members with
hoops, but the ductility and energy dissipation capacity were increased due to superior confinement
effect. Results also showed a tendency to increase energy dissipation as the yield strength of spiral
reinforcement was increased.
Acknowledgement: This work was supported by the Priority Research Centers Program through the Nationa
l Research Foundation of Korea (NRF) funded by the Ministry of Education (2019R1A6A1A03032988) ,
Experimental Study of Reinforced Concrete Columns with Confinement Effect
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