D e v e l o p m e n t o f C o n f i g u r a t i o n of T r a n s v e r s e R e i n f o r c e m e n t
657
Failure Modes
The failure modes of specimens are shown in Fig 4. All the specimens showed a flexural
failure accompanied by spalling and cracking of the surface concrete in the plastic hinge
region at both ends subjected to the maximum moment as shown in Fig. 5. Irrespective of
the configuration of transverse reinforcement, specimen AS, which was fabricated using
electric arc furnace oxidizing slag aggregate, was confirmed to have less spalling and
cracking in the surface concrete compared to specimen AN, which was fabricated using
natural aggregate. In addition, the S-type specimen was confirmed to have less spalling of
the surface concrete and buckling of the longitudinal reinforcement compared to the H-
type specimen, irrespective of the type of aggregate used.
Ductility of Specimens
The flexural capacity of the reinforced concrete columns can be evaluated based on the
ductility factor, where high ductility factor indicates superior flexural capacity. As shown in
Fig. 5, which shows the ductility factor of the specimens, specimen AS had a 40% higher
ductility factor compared to specimen AN, irrespective of the configuration of the
transverse reinforcement. Also, irrespective of the type of aggregate used, the S-type
specimen had an equal or greater ductility factor compared to the H-type specimen. Thus,
it was confirmed that the S-type configuration demonstrates an equal or higher ductility
factor compared to the H-type configuration, while it reduces the required amount of
transverse reinforcement by over 50%.
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Flexural moment (kN-m)
ACI-31811
Displacement (mm)
ACI-31811
S-AN
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Flexural moment (kN-m)
ACI-31811
Displacement (mm)
ACI-31811
H-AS
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Flexural moment (kN-m)
ACI-31811
Displacement (mm)
ACI-31811
S-AS
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ACI-318M11
Flexural moment (kN-m)
Displacement (mm)
ACI-31811
H-AN
Figure 3: Flexural moment versus displacement relationships of tested specimens
