• Steel and Composite Structures
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• 제14권3호
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• pp.229-242
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• 2013

Corrosion is important reason for the deterioration of the bond between reinforcing steel and the surrounding concrete. Corrosion of the steel mainly depends on its microstructure. Smooth S220, ribbed S420 and S500 grade reinforcing steels were used in the experiments. Samples were subjected to accelerated corrosion. Pullout tests were carried out to evaluate the effects of corrosion on bond strength of the specimens. S500 grade steel which has tempered martensite microstructure showed lower corrosion rate in concrete than S220 and S420 steels which have ferrite+perlite microstructure. S500 grade steel showed highest bond strength among the other steel grades in concrete. Bond strength between reinforcing steel and concrete increased with increase in the strength of steel and concrete. It also depends on whether reinforcing bar is ribbed or not.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1370-1376
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• 2009

Reinforcing steel works should be carefully controlled by the construction manager considering the severe fluctuation of the price of reinforcing steel bars and for the safety of structure in building constructions. In particular, preparing rebar placing drawings needs more effort and time than before because of the emergence of higher and more complicated buildings. Moreover, the experience of field engineers or foremen (fabricators or detailers) in preparing placing drawings gives rise to the differences in fabricated bar type and quantity of bars used. To address these problems, this study proposed the support system in preparing placing drawings for reinforcing steel works efficiency. In the near future, if this system can be made available on the web, multiple end-users will be able to share the result; the efficiency of rebar supply chain management will also be improved.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.197-202
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• 1997

Recently the interest in the reinforcing steel corrosion due to the use of sea-sand and deicing salt, marine environment, and carbonation in RC structures is increasing, therefore the studies on the corrosion control of reinforcing steel in concrete are vigorously proceeding. In this study, from the viewpoint of electrochemical process of steel corrosion in concrete we applied the impressed current system among the cathodic protections to reinforcing steel in concrete and ascertained the protection effect by half-cell potential, corrosion rate, and depolarization.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1991년도 가을 학술발표회 논문집
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• pp.80-85
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• 1991

This experimental study was performed to derive the relationship between the measured values(corrosion potential) and the actual amount of corrosion products(reinforcing steel weight loss rate). Also the growth of crack due to the steel corrosion was oberved. First, the reinforcing steel of R/C specimen was corroded with chloride penetration and accelerated galvanostatic corrosion method. And then, the corrosion potential of reinforcing steel was measured with nondestructive tester.

• Architectural research
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• 제20권4호
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• pp.129-135
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• 2018

In order to compare the development performance of headed reinforcing bar and straight reinforcing bar in tension for steel fiber reinforced concrete (SFRC), pullout test of specimens with reinforcing bar which was anchored on simple beam perpendicularly was conducted. The experimental variables were steel fiber volume ratio ($V_{Rsf}$), concrete compressive strength, and existence of head. As the result of test, splitting failure of concrete in the development direction of reinforcing bar in most specimens was observed. For development detail of headed reinforcing deformation bar, specimens with 1% $V_{Rsf}$ showed approximately 63%~119% increase in pullout strength compare to specimens with 0% $V_{Rsf}$. Test result shows that SFRC is more effective in increasing pullout strength for headed reinforcing bars than increasing pullout strength of straight bars.

• 콘크리트학회논문집
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• 제23권5호
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• pp.559-567
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• 2011

효율적인 철근콘크리트 구조물을 설계 시공하기 위하여, 최근 들어 고강도 철근에 대한 연구가 활발히 진행되고 있다. 그러나 고강도 철근은 일반강도 철근에 비하여 연신 능력이 낮은 것이 일반적이므로, 기존의 최소 연신율규격을 만족하지 못할 가능성이 있다. 또한 국내외 철근 규격의 최소 연신율 규정과 표점 거리 규정은 각 규격마다 상이하여, 동일한 철근이라도 적용하는 규격에 따라 적합 여부가 다르게 평가된다. 따라서 각 철근 규격을 비교 검토하고, 국내의 철근 규격 KS D 3504의 규정이 합리적인지 검토할 필요가 있다. 이 연구에서는 한국, 미국, 일본, 유럽, ISO 등 국내외 철근 규격의 최소 연신율 규정과 표점 거리 규정을 비교 분석하고, 철근 인장시험을 통하여 규격의 엄격성을 평가하였다. 그 결과, 국내 철근 규격인 KS D 3504가 가장 엄격한 것으로 평가되었다. 이 엄격성 비교 결과를 바탕으로 KS D 3504의 일반용 철근 규격의 최소 연신율 규정을 수정할 것을 제안하였으며, 내진용 철근 규격을 제안하였다.

• Architectural research
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• 제10권1호
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• pp.13-23
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• 2008

It is the purpose of this study to evaluate the structural performance of steel pipe splice for SD500 high-strength reinforcing bar, through a cyclic loading test. The experimental variables adopted in this study include the development length of rebar, the type of sleeve, and size of reinforcing bar, among others. The results of this study showed that the developed steel pipe splice system for SD500 high-strength reinforcing bar, retained the structural performance required in domestic, ACI and AIJ code. It is considered that the study result presented in this paper can be helpful in developing a reasonable design method for a steel pipe splice system for SD500 high-strength reinforcing bar.

• Steel and Composite Structures
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• 제35권4호
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• pp.509-525
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• 2020

Steel-concrete composite slabs with profiled steel sheeting are widely used in the execution of floors in steel and composite buildings. The rapid construction process, the elimination of conventional replaceable shuttering and the reduction of temporary support are, in general, considered the main advantages of this structural system. In slabs with the spans currently used, the longitudinal shear resistance commonly provided by the embossments along the steel sheet tends to be the governing design mode. This paper presents an innovative reinforcing system that increases the longitudinal shear capacity of composite slabs. The system is constituted by a set of transversal reinforcing bars crossing longitudinal stiffeners executed along the upper flanges of the steel sheet profiles. This type of reinforcement takes advantage of the high bending resistance of the composite slabs and increases the slab's ductility. Two experimental programmes were carried out: a small-scale test programme - to study the resistance provided by the reinforcing system in detail - and a full-scale test programme to test simply supported and continuous composite slabs - to assess the efficacy of the proposed reinforcing system on the global behaviour of the slabs. Based on the results of the small-scale tests, an equation to predict the resistance provided by the proposed reinforcing system was established. The present study concludes that the resistance and the ductility of composite slabs using the reinforcing system proposed here are significantly increased.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.579-584
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• 1997

This experimentation is to apperciation an efficiency of repair for processing crack by corrosion of steel reinforcing, Crack on concrete by corrosion of steel reinforcing is the fact that the first crack appear on the surface of water because of supplying is of oxygen and water. The crack processing is on surface to be contacted by air and to bottom as mainly the vertical direction from a surface of water. The experimentation gives rise to crack in model by electricity. Crack by corrosion of steel reinforcing is more internal crack than external crack. since it is so. crack by corrosion of steel reinforcing have to attention to repair or intermal crack.

• 한국안전학회지
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• 제25권6호
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• pp.128-136
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• 2010

In according with concrete structural design standard, it is common designing flexure reinforcement concrete to induce tension failure. So reinforcing ratio is limited to inducing tension failure. And maximum reinforcing ratio is regulated to protecting concrete compression strength caused by over reinforced building. Minimum reinforcing ratio is also limited in designing standard to protecting brittle failure as extremely using less reinforcing bar. But in minimum reinforcing ratio it is extremely conservative or it is sometimes impossible to induce stable tension-failure because they are depending on yield failure and experienced method and concrete designing standard strength. Therefore the purpose of the present paper is to evaluate the flexural behavior of minimum steel ratio of reinforced concrete of beams and to propose the guide-line of equation of minimum steel ratio by performing static flexural test of 16 beams according to size effect, number of steel, yielding stress of steel, and concrete compressive strength which are presumed effective variables. From experimental results, the equation of minimum steel ratio was newly proposed considered size effect.