• Proceedings of the KIEE Conference
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• 1998.07g
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• pp.2384-2386
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• 1998

In this paper, the system which can read the frequency and the power values of the generators, calculate the S.R., display the on-line graph and the off-line graph and manage the database of the generators was developed. This system should be more faster, comfortable and powerful than the present analysis method of the S.R. in real fields.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2010.04a
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• pp.445-448
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• 2010

본 연구는 섬유 보강 폴리머(Fiber Reinforced Polymers, 이하 FRP) bar로 보강된 콘크리트 깊은 보의 전단강도를 평가하기 위하여 전단경간비, 보강비, 주근의 종류를 변수로 총 6개의 실험체에 대한 전단 실험을 수행하였다. 전단실험을 토대로 FRP bar로 보강된 콘크리트 깊은보의 균열 및 처짐에 대한 거동 조사를 수행하였으며, ACI 318-08의 스트럿-타이 모델을 이용한 전단강도와 아치작용을 고려한 기존 제안식에 의한 전단강도를 비교 평가하였다. 그 결과, FRP bar로 보강한 실험체와 철근으로 보강한 실험체는 상이한 전단거동을 보였으며, FRP bar로 보강한 경우의 전단강도가 철근으로 보강한 경우보다 증가하는 것으로 나타났다. 전단강도 산정에 있어서는 ACI 318-08의 스트럿-타이 모델을 이용한 방법이 기존 제안식에 의한 방법보다 상대적으로 정확했다.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.113-122
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• 1999

The present study is to investigate the possibility of overestimation or underestimation when the ACI Code equations are used to evaluate the unbonded tendon stress. An experimental program was planned with 6 beams which divided into two groups. Each group consisted of 3 beams to check the possibility of overestimation or underestimation of unbonded tendon stress. The experimental results were also compared with various design equations including the one proposed by Moon and Lim. It was proven that the ACI Code equations may overestimate or underestimate the unbonded tendon stress in certain cases.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.405-408
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• 2004

The current design procedures of ACI 318-02, CE3-FIP and NZS 3101 for interior beam-column joints do not provide engineers with a clear understanding of the physical behavior of beam-column joints. In this paper, the failure strengths of the interior beam-column joint specimens tested to failure were evaluated using the 3-dimensional strut-tie model approach, 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 model approach were compared with those obtained from the other approaches, and the validity of the approach implementing a 3-dimensional strut-tie model was examined.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.11a
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• pp.277-280
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• 2006

This paper deals with the shear deformation charateristics of concrete beams strengthened with steel/FRP Bar. Applying the shear behavioral model based on shear deformation compatibility to RC beams tested by Ahmed K. El-Sayed et al.(2006), their transverse deformation in the web are calculated at ultimated loads after decoupling the shear carried by arch action in each beams. The calculated transverse deformation at ultimated loads are nearly same for the different reinforcement ratio. From these results, the temporary transverse deformation limit criterion is deduced. Using the proposed temporary limit criterion, the shear strength of concrete beams strengthen with FRP Bar tested by Ahmed K. El-Sayed et al.(2006) is predicted. These predicted values are compared with the measured values and the results are also compared with the current ACI and JSCE equation. The proposed method predicts the ultimate shear capacities more accurately than the equation of ACI and JSCE code. The predictions by the ACI and JSCE code are founded to be very conservative.

• Proceedings of the KIEE Conference
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• 2004.11b
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• pp.293-296
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• 2004

This paper proposes a new protective relaying algorithm using ACI(Advanced Computational Intelligence) and wavelet transform. To organize the advanced neuro-fuzzy algorithm, it is important to select target data reflecting various transformer transient states. These data are made of changing-rates of D1 coefficient and RSM value within half cycle after fault occurrence. Subsequently, the advanced neuro-fuzzy algorithm is obtained by converging the target data. As a result of applying the advanced neuro-fuzzy algorithm, discrimination between internal fault and inrush is correctly distinguished within half cycle after fault occurrence. Accordingly, it is evaluated that the proposed algorithm can effectively protect a transformer by correcting discrimination between winding fault and inrushing state.

• Journal of the Korea institute for structural maintenance and inspection
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• v.7 no.4
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• pp.171-181
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• 2003

This study concerns the prediction of shear capacity, as governed by concrete breakout failure, concrete pryout failure and steel failure, of single anchors located close to free edge and located far from a free edge and installed in uncracked, unreinforced concrete. For this purpose, the methods to evaluate the shear capacity of the single anchors in concrete are summarized and the experimental data are compared with capacities by the two present methods: the method of ACI 349-90 and concrete capacity design (CCD) method.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2019.11a
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• pp.110-111
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• 2019

In ACI 318-19 published recently, the conditions and development length equation to use the headed deformed bars were changed considerably. Although the use of the larger-diameter(No.14 and 18) headed deformed bars isn't yet permitted, the use of the high strength(80,000psi) headed deformed bars is permitted and the effect of bar-diameter($d_b$) on the development length is increased considerably. Therefore, structures using larger-diameter headed deformed bars will be expected to be affected by this code change. We will study the effect of the code change on the development design and find out the design optimization method to minimize the effect of the changed conditions and development length equation.

• Structural Engineering and Mechanics
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• v.78 no.4
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• pp.403-411
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• 2021

Ties are mandated by many design guidelines and codes to prevent the progressive collapse of buildings initiated by local failures. This study develops a model to estimate catenary/cable action capacity and the required ties in continuous reinforced concrete beams to bridge above the potential failed interior columns. The developed model is derived based on virtual work method and verified using test results presented in the literature. Also, parametric investigations are conducted to estimate the required ties in continuous reinforced concrete beams supporting one-way slab systems. A comparison is conducted between the estimated tie reinforcement using the developed model and that provided by satisfying the integrity provisions of the ACI 318-14 (2014) code. It is shown that the required tie reinforcements to prevent progressive collapse using the developed model are obviously larger than that provided by the integrity requirements of the ACI 318-14 (2014) code. It has been demonstrated that the increases in the demanded tie reinforcements over that provided by satisfying ACI 318-14 (2014) integrity provisions are varied between 1.01 and 1.46.

• International conference on construction engineering and project management
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• 2009.05a
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• pp.1313-1317
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• 2009

Deflections of Reinforced concrete structures must satisfy the permissible values and it is hard to predict the due to uncertainty of deflection of the reinforced concrete structures. Thus, many researchers have suggested a number of experimental equation of deflection against the uncertainty. In a specification, a procedure to evaluate flexure deflection using effective moment of inertia and moment-curvature relation is suggested. ACI offers a method using effective moment of inertia, which has been developed by Branson. Eurocode 2(EC2) suggests a procedure to evaluate deflection of reinforced concrete structure using moment-curvature relation. In this paper, a series of experiments were conducted on the singly reinforced concrete beams which have the same reinforcement ratio and different concrete strength. Therefore, the effect of the concrete strength on the deflection of the beams was analysed. The deflections obtained from the experiment were compared with the deflections calculated with ACI code and EC2.