• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2006년도 춘계 학술발표회 논문집(II)
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• pp.237-240
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• 2006

The corrosion of steel reinforcing bar has been the major cause of the reinforced concrete deterioration. GFRP(Glass Fiber-Reinforced Polymer) reinforcing bar has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. However, GFRP rebar is prone to deteriorate due to other degradation mechanisms than those for steel. The high alkalinity of concrete, for instance, is a possible degradation source. This paper presents the long-term deterioration of the GFRP rebar under alkali environmental condition.

• 토지주택연구
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• 제8권4호
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• pp.257-266
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• 2017

LH has been using ultra high strength reinforcing bars (SD500 and SD600), since 2011. Such a change requires an adjustment of the old extra rates of bar splice to reflect use of ultra high strength reinforcing bars, as these rates had been set based on SD400 bars. It is particularly difficult to calculate precisely rebar lap-splice locations for large areas, such as those in apartment buildings. This research aims to adjust the extra rates of bar splice to reflect a reasonable rate; the rebar lap-splice length is not an exact estimation, but instead, an extra rates of bar splice is set and the rebar lap-splice length is increased by 2% (D 10) - 7% (025) depending on the bar size. The subjects of this study are LH apartments undergoing frame construction. We studied the quantity estimations from the design drawings, and analyzed the settlement quantities of construction field. The results of the study revealed that, when each of the quantities are analyzed, consider adjusting the extra rates of bar splice of some rebar to 1% - 3.5%. This was caused by an overuse of reinforcing bars in onsite construction and the use of supporting bars that have not been reflected in the documents, among other reasons. Based on the results of our study, an improvement plan for the current extra rates of bar splice seems to be necessary, cutting or raising the rate depending on the analysis of the data. Through this study, we expect to contribute to the calculation of reasonable construction costs, improvements in the quality of rebar work, and improvements in the capacity of design techniques for apartment buildings.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문 발표회
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• pp.53-58
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• 2003

Concrete structures move wholly with concrete and rebar, so they endure external force, but recently the embedded rebar in concrete has been corroded by environmental, physical and chemical factors, the embedded rebar corrosion influences concrete structure to deteriorate structure capacity. To revaluate effect to deterioration of concrete structure according to corrosion of rebar, the researcher mostly examined into corrosion rebar and complex relation of concrete. In that there are flexural strength deterioration of corrosion concrete structure and the bond strength of concrete. But It has not sufficiently studied about physical characteristic of corrosion rebar itself. In this study I will compare specification of rebar through corrosion experiment with corrosion ratio of rebar according to diameter and revaluate. And will investigate the effect to strength characteristic of rebar according to corrosion ratio.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2003년도 학술.기술논문발표회
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• pp.53-58
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• 2003

Concrete structures move wholly with concrete and rebar, so they endure external force, but recently the embedded rebar in concrete has been corroded by environmental, physical and chemical factors. the embedded rebar corrosion influences concrete structure to deteriorate structure capacity. To revaluate effect to deterioration of concrete structure according to corrosion of rebar, the researcher mostly examined into corrosion rebar and complex relation of concrete. In that there are flexural strength deterioration of corrosion concrete structure and the bond strength of concrete. But It has not sufficiently studied about physical characteristic of corrosion rebar itself. In this study I will compare specification of rebar through corrosion experiment with corrosion ratio of rebar according to diameter and revaluate. And I will investigate the effect to strength characteristic of rebar according to corrosion ratio.

• Architectural research
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• 제22권1호
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• pp.33-39
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• 2020

In this study, side-face blowout failure strength of high strength headed reinforcing bar, which is vertically anchoring between RC or SFRC members, is evaluated throughout pullout test. The major test parameters are content ratio of high strength steel fibers, strength of rebar, length of anchorage, presence of shear reinforcement, and the side concrete cover thickness planned to be 1.3 times of the rebar. In pullout test, tensile force was applied to the headed reinforcing bar with the hinged supports positioned 1.5 and 0.7 times the anchorage length on both sides of the headed reinforcing bar. As a result, the cone-shaped crack occurred where the headed reinforcing bar embedded and finally side-face blowout failure caused by bearing pressure of the headed reinforcing bar. The tensile strength of specimens increased by 13.0 ~26.2% with shear reinforcement. The pullout strength of the specimens increased by 3.6 ~15.4% according to steel fiber reinforcement. Increasing the anchoring length and shear reinforcement were evaluated to reduce the stress bearing ration of the total stress.

• 한국농공학회지
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• 제45권2호
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• pp.58-67
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• 2003

Over the last decade fiber-reinforced polymer (FRP) reinforcement consisting of glass, carbon, or aramid fibers embedded in a resin such as vinyl ester, epoxy, or polyester has emerged as one of the most promising and affordable solutions to the corrosion problems of steel reinforcement in structural concrete. But reinforcing rebar for concrete made of FRP rebar has linear elastic behavior up to tensile failure. For safety a certain plastic strain and an elongation greater than 3% at maximum load is usually required for steel reinforcement in concrete structures. The same should be required for FRP rebar. Thus, the main object of this study was to develop new type of hybrid FRP rebar Also, this study was evaluated to the mechanical properties of Hybrid FRP rebar. The Manufacture of the hybrid FRP rebar was achieved by pultrusion, and braiding and filament winding techniques. Tensile and interlaminar shear test results of Hybrid FRP rebar can provide its excellent tensile strength-strain behavior and interlaminar stress-strain behavior.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.21-22
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• 2023

In reinforced concrete constructions, reinforcing bar generates more CO₂ per unit weight than other construction materials. In particular, cutting and bending rebar is the main source of rebar waste in the construction industry. Rebar-cutting waste is inevitable during the construction of a reinforced concrete structure since the rebar is not manufactured as designed. Large amounts of waste can be avoided by utilizing optimal cutting patterns and schedules. This research provides a fundamental analysis of the automatic calculation of column rebar length using BIM-based shape codes to minimize cutting waste to near zero. By employing this approach in practice, it is possible to minimize the rate of rebar-cutting waste, reduce costs, shorten construction duration, and reduce CO₂ emissions. In addition, the development of this research will serve as a clue for the development of BIM-based rebar layout automation algorithms.

• 한국구조물진단유지관리공학회 논문집
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• 제16권1호
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• pp.110-119
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• 2012

최근 고부식 환경에 놓여 있는 철근 콘크리트 구조물의 철근 부식 문제를 해결할 수 있는 방안 중 하나로 뛰어난 내부식성을 가진 섬유복합체(Fiber Reinforced Polymer, FRP)로 제작된 보강근이 주목받고 있다. 유리섬유복합체로 제작된 보강근이 상용화된 상태이나 가격, 철근보다 낮은 탄성계수, 취성파괴 특성 등의 이유로 사용 실적은 많지 않은 것이 현실이다. 이러한 문제점을 해결하기 위한 방편 중 하나는 유리섬유복합체 보강근의 성능을 고도화하는 것이다. 성능 고도화를 통해 강도 대비 가격을 낮출 수 있으며, 인장성능을 향상시킬 수 있다. 본 연구는 주어진 재료와 조건 하에서 보강근 성능에 영향을 미치는 인자들의 효율성 향상을 통한 고인장 성능 유리섬유복합체 보강근의 개발에 관한 것이다. 이를 위해 구성재료와 제작방법 등 유리섬유복합체 보강근의 인장성능에 영향을 미치는 인자들에 대해 분석을 수행하여 개선 방안을 제안하였으며, 이를 통해 보강근의 주재료인 유리섬유의 성능을 기존 제품보다 더욱 효율적으로 활용하는 보강근을 제작하였으며, 다양한 변수에 대한 인장시험을 통하여 그 성능을 비교 분석함으로써 개선 방안의 적절성을 검증하였다.

• 한국구조물진단유지관리공학회 논문집
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• 제14권1호
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• pp.78-83
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• 2010

철근부식에 의해 발생된 녹은 철근 주위의 콘크리트에 팽창압력을 발생시켜 콘크리트의 균열유발, 피복콘크리트의 박리나 탈락, 철근의 단면적 감소들을 야기 시킨다. 또한 철근콘크리트 구조물 내에 매입된 철근의 부식은 철근과 콘크리트의 일체 거동을 저하시킴으로써 구조물이 외력에 견딜 수 있는 구조성능의 감소를 초래한다. 본 논문에서는 3차원 스캐너를 이용하여 철근이 부식됨에 따른 철근의 표면적을 측정하여 부식률과 표면 거칠기와의 관계를 파악하였다. 철근부식률 1~2%의 경우에서는 철근 표면적이 증가하는 것으로 나타났다. 이는 동일 범위내에서 철근의 부착강도가 증가한 기존의 실험결과와 매우 유사한 결과를 나타낸다. 철근부식률 2% 이상에서는 오히려 표면적이 감소하였으며, 이는 단면적 손실로 인한 기존 부착강도 실험과 부합되는 결과를 나타냈다.

• 한국건축시공학회지
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• 제8권1호
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• pp.83-90
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• 2008

The reinforcing steel process is composed of the development of placing drawing, cutting and bending, and the placement and fabrication of the reinforcement, and is participated in by reinforcement detailer, the fabricator and placer. Because the reinforcing steel process-from estimating and rebar detailing, to production, material tracking, billing, and general accounting-is conducted by many participant, reinforcement details based on building code and reinforcing bar detailing standards are essential. The process, however, holds some problems. Building code has been revised recently, and the utilization of placing drawings was proved to be low, and the reinforcement estimating in early stage of the process is below what is required for placement. Therefore, in this study, a survey was conducted to the reinforcement detailer, the fabricator and placer of domestic construction industry. According to the analysis of the survey, the reinforcement details on site was not standardized. The improvement in reinforcing steel detailing standards was sought by analyzing the results of the survey including reinforcement constructability.