• Magazine of the Korea Concrete Institute
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• v.6 no.6
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• pp.180-189
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• 1994

A practical methodology to detect and localm da~nagc in rcinforced concrete structures by utilizing modal response parameters of as built and tiamaged states is presented. First, a damage detection algorithm which yields information on the, location of damage directly from changes in mode shapes of structures is outlined. Next, the algorithm is implemented to detec and localize damage in a real, 1 1/3 scale, reinforced concrete structure. A set of pre-damage and post damage modal parameters are used for I he damage detection exercise. The results of the damage prediction show that the proposed algorithm can correctly locate the damage inflicted in the test structure.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.17 no.2
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• pp.131-140
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• 2004

It really needs fuzzy decision making of integrity assessment considering about both durability and load carrying capacity for maintenance and administration, such as repairing and reinforcing. This thesis shows efficient models about reinforced concrete structure using CART-ANFIS. It compares and analyzes decision trees parts of expert system, using the theory of fuzzy, and applying damage & diagnosis at reinforced concrete structure and decision trees of integrity assessment using established artificial neural. Decided the theory of reinforcement design for recovery of durability at damaged concrete ＆ the theory of reinforcement design for increasing load carrying capacity keep stability of damage and detection. It is more efficient maintenance and administration at reinforced concrete for using integrity assessment model of this study and can carry out predicting cost of life cycle.

• Journal of Korean Association for Spatial Structures
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• v.6 no.2 s.20
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• pp.123-129
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• 2006

Recently, many researches have been conducted about reinforced concrete structures strengthened with FRP plates. In case of structures strengthened with FRP plates, the issue of premature debonding FRP plate has been raised through many previous researches. The purpose of this paper is what structural behavior and flexaural capacity of reinforced concrete beams which are strengthened for flexure is investigated about the using secondary ironware in the method of external bonded CFRP plate, and the method of near surface mounted CFRP-Rod. Also, in order to evaluate flexural capacity, experiments of the reinforced concrete beams with exteranl bonded CFRP plate and near surface mounted CFRP-Rod have been compared and investigated.

• Magazine of the Korea Concrete Institute
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• v.11 no.2
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• pp.251-259
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• 1999

Recently, large scale concrete structures exposed to severe environments are increasingly built in various locations, The corrosion may severely affect the durability and service life of such a concrete structure. It is, therefore, necessary to develop a method to enhance the corrosion resistance of a concrete, The purpose of this paper is, therefore, to investigate the corrosion resistance and bond strength characteristics of anti-corrosive cement coated reinforcements. To this end, a comprehensive experimental study has been done to explore the corrosion and bond behavior of those coated reinforcements. The test results indicate that the anti-corrosive cement coated reinforcements do not exhibit any corrosion after corrosion tests and the bond strengths are very good as much as plain bar. It is seen that the anti-corrosive cement coated reinforcements can be efficiently used to enhance the durability of reinforced concrete structures.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.199-200
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• 2009

This research developed a long-term crack width prediction model based on bond characteristics that considered steel corrosion, concrete shrinkage and creep in cracking stabilized structural concrete members.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.5
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• pp.475-485
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• 2009

In this paper a two-step algorithm is proposed to efficiently generate rebar elements from 3D CAD data in the context of CAD/CAE data transfer. The first step is an algorithm to identify various type rebar objects and their attributes by analyzing 3D CAD data in STEP format, which is one of the international data standards. The second algorithmic step is a procedure to generate one-dimensional rebar elements from the object data made through the first step for finite element analysis or other CAE tasks. Successful rebar element data generation from real 3D CAD data for a reinforced concrete structure shows the efficacy of the proposed algorithm.

• Magazine of the Korea Concrete Institute
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• v.1 no.2
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• pp.93-100
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• 1989

철근콘크리트부재의 강도는 여러 가지 요인으로 인하여 변이를 보이고 있다. 주요 요인들은 콘크리트나 철근의 강도 및 역학적 특성의 변이, 시공오차등이다. 이들중 콘크리트의 강도는 상대적으로 높은 불확실성을 가지며, 다양한 요인(배합, 운반, 타설, 양생등)에 의해 변화정도가 영향을 받는다. 본 연구에서는 국내 철근콘크리트 구조물이 가지는 신뢰도의 수준을 분석하기 위한 기초자료 조사로서, 현장에서 타설되는 콘크리트를 설계강도별로 직접채취하여 습윤양생과 현장조건양생을 통하여 콘크리트의 28일 압축강도의 확률적 특성을 분석하였다. 분석된 결과를 이용하여 현장타설 부재내에서의 콘크리트의 압축강도를 추정하였다.

• Computational Structural Engineering
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• v.11 no.4
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• pp.295-307
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• 1998

철근콘크리트 보에 대해서 인장강화효과의 소성힌지길이를 고려한 재료비선형 해석을 수행하였다. 비선형 해석에서 자유도가 많은 대형구조물에 적용시키기에는 많은 제약이 따르는 복잡한 층상해석기법을 사용하는 대신 단면해석을 통해 미리 구성된 모멘트-곡률 관계를 이용하였으며, 유한요소해석에서 사용요소의 크기에 따른 수치해석상의 오차를 줄이기 위해 인장강화효과와 소성힌지길이 개념을 도입하였다. 마지막으로 제안된 해석 알고리즘의 타당성을 검증하기 위하여 해석결과와 실험결과간의 상호 관계를 비교, 분석하였다.

• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.2
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• pp.184-192
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• 2010

The member deflection is one of the most important considerations for the serviceability evaluation of reinforced concrete (RC) structures, and the concept of the effective moment of inertia has been generally used for its estimation. However, the actual service load applied on an existing RC beam may not be easily obtained, for which the estimation of beam deflection by existing methods can be difficult to obtain. Therefore, based on the correlation between cracks and deflection in a RC beam, this study proposed a method to estimate the deflection of RC beams directly from the condition of cracks not using the actual loads acting on the member as its input data. The proposed method extensively utilized the relationships among sums of crack widths, average strains, and curvatures, and modification factors obtained from regression analysis were also introduced to improve its accuracy. The deflections of members were successfully estimated by the proposed method independent from applied loads, which was also easy to apply compared to the existing methods based on the effective moment of inertia.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.14 no.3
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• pp.391-402
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• 1994

One of the most important design concept for reinforced concrete structures is to achieve a ductile failure mode, and also moment redistribution for economic design is possible in case that adequate ductility is provided. Flexural ductility index is, therefore, used as a reference for possibility of moment redistribution as well as for prediction of flexural behavior of designed R.C. structures. Ductility index equations, however, provide approximate values due to the linear concrete compressive stress assumption at the tension steel yielding state. Theoretically more exact ductility index is calculated by a numerical analysis with the realistic stress-strain curves for concrete and steel to be compared with the result from tire ductility index equations. Variation of ductility index for the selected variables and the reasonable maximum tension steel ratio for doubly reinforced section are investigated. A moment-curvature curve model is also proposed for future research on moment redistribution.