• Proceedings of the Korea Concrete Institute Conference
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• 2002.10a
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• pp.179-184
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• 2002

The evaluation equation of torsional moment for prestressed concrete members in ACI 318-95 ignores the contribution of concrete, T$_{c}$. Several research indicates that the current ACI code is not successful in predicting the observed torsional moment of the PSC beams with reasonable accuracy. This paper proposes an evaluation equation of torsional moment taking into account the inter-effects between concrete and torsional reinforcement on the torsional resistance of the PSC beams. According to the comparison with the 31 test results, the torsion equation in ACI code underestimated or overestimated the real torsional moment of prestressed concrete beams. On the other hand, the proposed torsional equation is shown to be in a good agreement with experimental results.s.

• Magazine of the Korea Concrete Institute
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• v.7 no.3
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• pp.164-174
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• 1995

Reliability of RC beanls designed for flexure under the provisions of ACI Building Code is analyzed. The results are compared with those obtained previously. It is shown that in some cases the reliability is inadequate and changes substantiallv with reinforcernent ratio. The probability of brittle failure appears to be rather high. The reasons for these phenomena are revealed and some measures to remedy the situation are recommentied. hluch attention is given to the conditions askthey stand at present in Korea.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.676-678
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• 2005

In underground power cable system, the apparent impedance at the relaying point can be changed because of the complicated configuration such as the various earth resistance and the operation of sheath voltage limiter (SVL). They have a bad effect on the distance relay operation Therefore, in this paper, in order to solve this problem, the authors are going to anly the advanced computational technique(ACI) of FR-FIS(Fuzzy Relation-based Fuzzy Inference System).

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05a
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• pp.42-45
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• 2006

This study investigated headed bar anchorage of exterior beam column joints in nuclear power plants. In nuclear power plant structures, anchorage of headed bar is recommended to satisfy ACI 349-01 App. B that are based on the Concrete Capacity Design (CCD) method. However, CCD method may lead to very conservative results for beam column joints where head is anchored within the diagonal strut and concrete is confined by transverse rebar. Compared with results of 5 joint specimens, the anchorage capacities calculated by ACI 349-01 are underestimated by 70-90%. Therefore, it is necessary to amend ACI 349-01 for the mechanical anchorage in beam column joints.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.87-88
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• 2009

In this research project, 24 tests are performed to find out a behavior and shear breakout capacity of large anchor system exceeding 2 inch(50mm) in anchor bolt diameter($d_0$) and 25 inch(635mm) in effective embedment($h_{ef}$) not addressed by ACI 349-01 Appendix B (ACI 349 2001). On this report, analysis results are presented that this variables influence on behavior and shear breakout strength through those of test results.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.409-412
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• 2003

ACI design code is not capable of evaluating the inter-effects between concrete and torsional reinforcement on the torsional resistance of the reinforced concrete beams. In this study, the failure strengths of the ten reinforced concrete beams subjected to pure torsion were evaluated using 3-dimensional strut-tie models. The analysis results obtained from the present study were compared with those obtained from the ACI design code. The comparison showed that the accuracy and performance of the present method were better than the ACI design code. Thus, the method implementing a 3-dimensional strut-tie model can be possibly applied to the analysis and design of the reinforced concrete beams subjected to pure torsion as a rational design method.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.161-164
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• 2003

This experimental investigation was conducted to examine the seismic performance of reinforced concrete bridge columns. The columns were subjected to a constant axial load and a cyclic horizontal load-inducing reversed bending moment. The variables studied in this research are the volumetric ratio of transverse reinforcement ($P_s$ =0.96, 1.44 per cent) and axial load ratio (0.05, 0.1, 0.2 P/$P_o$). Test results show that bridge columns with 50 per cent higher amounts of transverse reinforcement than that required by seismic provisions of ACI 318-02 showed ductile behaviour. For bridge columns with axial load ratio(P/$P_o$) less than 0.2, the ratio of $M_{max}$ over $M_{aci}$, nominal moment capacity predicted by ACI 318-02 provisions, is consistently greater than 1 with approximately a 20 percent margin of safty.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2017.05a
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• pp.200-201
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• 2017

Generally, a lot of reinforcements are used in nuclear power plant concrete structures, and it may cause several potential problems when concrete is poured. Because of the congestion caused by hooked bars, embedded materials, and other reinforcements, it is too difficult to pour concrete into structural member joint area. The purpose of this study is to change ACI 349 Code for using the large-size(57mm) and high-strength(Gr.80) headed deformed bars instead of standard hooked bars in nuclear power plant concrete structures in order to solve the congestion problems.

• Proceedings of the Korea Concrete Institute Conference
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• 1996.10a
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• pp.337-344
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• 1996

Reinforced concrete deep beams with conpressive strengths in the range of 500kg/$\textrm{cm}^3$~750kg/$\textrm{cm}^3$ were tested under two-point loding. All the beams were singly reinforced with main steel percent $\rho$=1.29% and with nominal percentage of vertical shear reinflrcements $\rho_v$=0.26%. According to shear-span to depth ratio a/d. The beams were tested for four horizontal shear reinforcement ratio $\rho_h$, ranging from$\rho_h$=0.0 to $\rho_h$=0.53. The results indicate that the horizontal shear reinforcements of beams have an effect on failure load and on ductile behavior of deep beams. The test results are compared with predictions based on the current ACI Building Code. The computated reports in the paper will have designers assured for design of high strength concrete deep beam. Though ACI Code is relatively conservative and tend to non-economical, ACI Code has the merit that is easy to use.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.183-186
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• 2005

The Current design procedures of ACI 318-02 and CEB-FIP for the exterior beam-column joints do not provide engineers with a clear understanding of the physical behavior of the beam-column joints. In this paper, the failure strengths of the exterior beam-column joint specimens tested to failure were evaluated using the approach implementing 3-dimensional strut-tie models, design criteria of ACI 318-02, ACI-ASCE committee 352 and Park and paulay, and softened strut-tie model approach. The analysis results obtained from the 3-dimensional strut-tie models were compared with those obtained from the other approaches, and the validity of the approach implementing 3-dimensional strut-tie models were examined.