• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.629-634
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• 2000

Comparing with single structure constructed with reinforced concrete or steel, composite structures have a great advantage. However, in case of nuclear power structure, the application of a conventional single structure (reinforced concrete or steel structure) inflicts a heavy loss on a economical and constructive efficiency. But, the application of composite slab to nuclear power structure could compensate these deficiency. Therefore, in this study, the structural behavior of composite slab in nuclear power structure is observed to assure economical and constructive efficiency.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2000년도 봄 학술발표회 논문집
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• pp.303-308
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• 2000

During the past few decades, several composite steel-concrete structural systems have been used and the demand of SRC (Steel Reinforced Concrete) structure increases on the construction of coping structures. But drying shrinking of concrete which is not uniform and the additional restraining effects of encased steel in concrete may cause the crack which leads to harmful damage to structure. In this study, specimens were made to show the restraining effects of embeded-steel in concrete and the differential drying shrinkage strains at various position of concrete were measured and analysed by Compensation Line Method. The results showed that there were remarkable difference in the drying shrinkage according to 속 depth of the concrete, and the tensile stress of the concrete near to encased steel showed the significant amount of stress contrary to 속 specimen which has no embeded-steel.

• 한국안전학회지
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• 제28권6호
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• pp.29-35
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• 2013

The purpose of this study is to investigate the steel bar corrosion and degree of reinforced concrete bridge, and analyze the cause of corrosion occurrence. Therefore they could ensure the durability and stability as to suggest the corrosion prevention of reinforced concrete structure. To study the corrosion state reinforced concrete structure, We investigate the cover of concrete, the compressive strength by schmidt hammer, the neutralization test of site, the compressive strength of core and the measurement of neutralized depth. As the results of test, the corrosion-grade of reinforced concrete structure which the degree of corrosion is 3, 4 degree get to 18% in the used time of 40 years and the time elapsed of 25 years. Therefore the corrosion of steel bar give rise to public discussion. The degree of corrosion is serious, and the neutralization come to the cover of concrete.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 가을 학술발표회 논문집
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• pp.453-458
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• 1996

In reinforced concrete structure, it is very important to secure ductile performance of column because the columns become brittle failure and cause the collapse of an entire structure and the damage of human life. This study is intending to seek the quantity of transverse steels in square reinforced concrete columns which is derived from moment-curvature analysis of cross section about various arrangements of transverse steel and the ratio of axial force and to propose the design method to secure the sufficient ductile behavior subjected to complex loading.

• 대한건축학회논문집:구조계
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• 제34권7호
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• pp.3-10
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• 2018

Steel fiber reinforced concrete can improve the resistance to cracking by adding steel fibers when mixing concrete. It can reduce the temperature and shrinkage cracks, and its flexural performance can be improved by increasing the effective moment of inertia. In this study, the deck-plate was used to replace the concrete form and reinforcing bars, and the steel fiber reinforced concrete was used to control the shrinkage and temperature cracks, and improve the flexural performance of the slab. Total 9 slab specimens were tested for analyzing the structural performance and serviceability. As a results, flexural capacity of the slab with deck-plate was evaluated to be superior to that of the normal reinforced concrete slab specimens with the same tensile reinforcement. The steel fiber reinforced concrete was found to have about 8% flexural capacity increase depending on the steel fiber content $15.7kg/m^3$. Also, in terms of flexural stiffness, the specimens using steel fiber reinforced concrete for the same parameters were evaluated to have a stiffness increase of about 30% compared with the case of using ordinary concrete. Especially, it was found that the stiffness of the test results was significantly higher than the analytical result because the increase of the tensile strength of the steel fiber reinforced concrete is not reflected in the current structural code.

• 대한건축학회논문집:구조계
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• 제35권8호
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• pp.131-138
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• 2019

Since concrete has a low tensile strength compared to the compressive strength, reinforced concrete flexural members represent easy crack occurance under a small load. In order to overcome this problem, steel fiber reinforced concrete has been developed to compensate the tensile strength and brittleness of members. However, in the design formula of the domestic building code, it is not specified in the design formula reflecting the material characteristics. Therefore, the field application of the steel fiber reinforced concrete have had many restrictions. In this study, a flexural tensile strength model of steel fiber reinforced concrete is proposed by collecting and analyzing the material properties of material test results conducted by various researchers, and verified by the test results of cracking and stiffness evaluation of flexural members based on the proposed model. As a result of this study, the flexural tensile strength model of steel fiber reinforced concrete which can reflect the mixing ratio and aspect ratio of the steel fiber was proposed and the validity of the proposed material model equation was evaluated from the load-deflection relationship in the flexural test of the slab member.

• 한국구조물진단유지관리공학회 논문집
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• 제3권3호
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• pp.129-137
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• 1999

Reinforced concrete structures using early age concrete were result in the degradation of structural performance due to crack, overload, unexpected vibration and impact load. It demands urgently that reinforced concrete structure using early age concrete should be improved the serviceability and structural performance with the application of new fiber materials. Therefore specimens, designed by the test varibles, such as with or without stirrup and percent of steel fiber incorporated, were constructed and tested to evaluate and develop the structural performance of reinforced steel fiber concrete beam. Based on the test results reported in this study, the following conclusions are made. Specimens, designed by the over 0.75% of steel fiber incorporated, were showed the ductile behavior and failed slowly with flexure and flexure-shear. Comparing with the load-displacement relationship of specimen BSS, designed by the recommendations of the Ministry of Construction and Transportation, reinforced steel fiber concrete beam using early age concrete, over 0.75% of steel fiber incorporated, gets enough load carrying capacity and ductility. Increasing the percent of steel fiber incorporated(0.25~2.0%), the ultimate shear stress of each specimen were increased 12~40% than that of control specimen SSS.

• 한국강구조학회 논문집
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• 제22권5호
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• pp.455-463
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• 2010

본 연구는 철근콘크리트 구조와 강판 콘크리트 구조가 혼합되어 이질접합부가 있는 보형 구조물의 역학적 특성을 평가하기 위하여 수행하였다. 강판콘크리트 구조는 현재 국내와 일본, 미국 등에서 연구가 진행되고 있고, 대규모 산업설비에서 철근콘크리트 구조의 대안으로 실험연구가 수행되고 있다. 본 연구에서는 대규모 철근콘크리트 구조물에 강판 콘크리트 구조를 적용할 경우를 가정하여 보 형태의 구조물에 강판 콘크리트 구조와 철근 콘크리트 구조를 적용하여 이질접합부를 만들고, 면외하중을 파괴 시까지 가력하여 이질접합부를 가진 보형실험체의 휨 내력 및 구조특성을 평가하기 위하여 실험연구를 수행하였다.

• 산업기술연구
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• 제26권B호
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• pp.111-118
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• 2006

The reinforced concrete structure is one of the most popular structures in real construction. Concrete has been strengtened rapidly due to the development of new material and construction technology. But as the concrete has been getting stronger, the brittleness of material has increased and the better ductility has been required. So, the study for strengthening stiffener has been urgently needed. As we said above, it is expected that the use of high strength steel and concrete will be increased. However, The experimental data is not enough for solving problems of the use of high strengthened steel and concrete. In this research, we analyzed 45 combinations of the strength levels of concrete, the thickness of material and the steel strength with regard to simple Reinforced Concrete SLAB Beam bridge. The program MIDAS CIVIL was used to find the optimal combination. As a result, it was found that strength ratio per unit section is in inverse proportion to the strength of material and that the strengths of steel are respectively 400 MPa for low strengthened concrete and 300 MPa for high strengthened concrete. For economic aspect and usability, the effect of high strength steel is not as high as we expected it would be.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2004년도 학술.기술논문발표회
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• pp.21-25
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• 2004

The column for Steel Framed Reinforced Concrete Structure (SFRCS) and the column for Reinforced Concrete Structure (RCS) could be the most common building structure. The increasing of the need for massive space hasaffected the size of building components for supporting the massive structure. However, the changing of components size makes inefficient space of building. Hence, to meet the need for acquiring efficient space comparing the budget and cost the new structure method, Concrete Filled Tube Steel (CFT), was developed. CFT is the structure for which steel tube instead of other materials such as wood for holding concrete is used. The most benefit of this one is to help in reducing the size of the building components and local buckling because of tube steel holding concrete. For this reason, this research will examine the probability of applying CFT on construction sites by using the concrete (800kgf/$\textrm{cm}^2$) especially for CFT through the data from the real size mock-up.