• Computers and Concrete
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• 제14권6호
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• pp.711-725
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• 2014

The purpose of this study is to evaluate the behavior and the strength of SRG (Steel Reinforced Grout) externally strengthened Reinforced Concrete (RC) beams by using a nonlinear numerical analysis. The numerical simulation was carried out by using a three-dimensional (3D) finite element model. An interface element with a suitable damage model was used to model the connection between concrete surface and SRG reinforcing layer. The reliability of the finite element 3D-model was checked using experimental data obtained on a set of three RC beams. The parameters taken into consideration were the external configuration, with or without U-end anchorages, the concrete strength, the amount of internal tensile steel reinforcement. Conclusions were made concerning the strength and the ductility of the strengthened beams by varying the parameters and on the effectiveness of the SRG reinforcing system applied with two types of external strengthening configuration.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1997년도 봄 학술발표회 논문집
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• pp.557-564
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• 1997

This research is aimed to evaluate the effects of repair conditions, axial load intensities and the enlargement of cross sections after strengthening with steel plate and on the structural behavior of the reinforced concrete columns subjected to axial and lateral loadings. 6 columns were tested under uniform axial compression and concentrated load at the midspan until failiure occurs. As test results, It has been found that the amount of grout bar and the condition of strengthening significantly affect the behavior or reinforced concrete column with steel plate and grout 4 bar (C-G4S2 serise) and enlarged reinforced concrete column with steel plate and grout 8 bar (C-G8S2 serise) are increased to 1000% and 1200% in comparison of those of unstrengthened reinforced concrete columns, respectively

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2015년도 춘계 학술논문 발표대회
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• pp.65-66
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• 2015

In this study, it evaluate mecahnical performance and impact resistance performance of fiber reinforced concrete, fiber reinforced mortar and preplace grout mortar. steel fiber, nylon fiber and polypropylene fiber are reinforced 1vol.% 2vol.% 10vol.% by each fiber type. It evaluate impact resistance performance to use projectile 10mm of 400m/s velocity. As a result, mechnical performance and impact resistance performance of fiber reinforced preplace grout mortar are improved a lot by 10% fiber reinforced ratio.

• Steel and Composite Structures
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• 제34권6호
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• pp.877-889
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• 2020

This work features the outcomes of an empirical investigation into the characteristics of steel reinforced grout (SRG) composite - concrete interfaces. The parameters varied were loading rate, densities of steel fibres and types of load displacement responses or measurements (slip and machine grips). The following observations and results were derived from standard single-lap shear tests. Interfacial debonding of SRG - concrete joints is a function of both fracture of matrix along the bond interface and slippage of fibre. A change in the loading rate results in a variation in peak load (P_max) and the correlative stress (σ_max), slip and machine grips readings at measured peak load. Further analysis of load responses revealed that the behaviour of load responses is shaped by loading rate, fibre density as well as load response measurement variable. Notably, the out-of-plane displacement at peak load increased with increments in load rates and were independent of specimen fibre densities.

• Earthquakes and Structures
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• 제17권2호
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• pp.205-219
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• 2019

In Peru, construction of dwellings using confined masonry walls (CM) has a high percentage of acceptance within many sectors of the population. It is estimated that only in Lima, 80% of the constructions use CM and at least 70% of these are informal constructions. This mean that they are built without proper technical advice and generally have a high seismic vulnerability. One way to reduce this vulnerability is by reinforcing the walls. However, despite the existence of some reinforcement methods in the market, not all of them can be applied massively because there are other parameters to take into account, as economical, criteria for seismic improvement, reinforcement ratio, etc. Therefore, in this paper the feasibility of using five reinforcement techniques has been studied and compared. These reinforcements are: welded mesh (WM), glass fiber reinforced polymer (GFRP), carbon fiber reinforced polymer (CFRP), steel bar wire mesh (CSM), steel reinforced grout (SRG). The Multi-Criteria Decision Making (MCDM) method can be useful to evaluate the most optimal strengthening technique for a fast, effective and massive use plan in Peru. The results of using MCDM with 10 criteria indicate that the Carbon Fiber Reinforced Polymer (CFRP) and Steel Reinforced Grout (SRG) methods are the most suitable for a massive reinforcement application in Lima.

• 한국터널지하공간학회 논문집
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• 제3권1호
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• pp.11-19
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• 2001

이 연구는 강관 보강형 다단 그라우팅공법의 설치 및 절단 시 어려움, 부식에 취약한 문제점 등을 개선하는데 목적이 있으며, 강관 대신에 고강도 유리섬유(fiberglass)를 이용한 FRP(Fiberglass Reinforced Plastic)의 적용성에 대한 연구를 수행하였다. 연구결과는 강관에 비하여 FRP 보강재의 가격이 높긴 하지만 시공성 및 내구성 등에서 우수한 것으로 파악되었다. 그리고 FRP 보강재의 형상에 따른 수치해석 결과에서는 국외에서 상용화 된 판상형 보강재 보다 등각곡선형 보강재가 더 구조적 측면에서 효율적임을 알 수 있었고, 그라우트 복합체에 대한 굴곡강도시험 결과에서는 강관과 FRP 보강재의 지보효과가 유사한 것으로 평가되었다.

• 한국구조물진단유지관리공학회 논문집
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• 제18권6호
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• pp.21-29
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• 2014

본 연구에서는 모노파일지지구조의 고성능 그라우트연결부의 부착거동을 다루고 있다. 강관파일 연결부의 일체화를 위하여 섬유보강 고성능 그라우트를 개발하였으며, 재령 7일 압축강도 125MPa와 직인장강도 7.5MPa를 나타내었다. 축하중을 받는 상태에서의 그라우트의 부착거동을 평가하기 위하여 강관파일에 그라우트를 충진하여 부착실험을 수행하였으며, 그 결과를 기존의 설계기준과 분석하였다. 실험변수는 섬유혼입율 (0%, 0.5% and 0.9%), 섬유의 형상비 (60 and 80)와 전단키의 높이와 간격의 비 (0.013 and 0.056)로 선정하였다. 실험결과 최대부착강도는 30.8MPa로 관찰되었으며, 섬유 혼입율보다는 전단키의 높이와 간격의 비가 부착강도에 영향을 미치는 것으로 분석되었다.

• Steel and Composite Structures
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• 제23권5호
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• pp.585-596
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• 2017

Tubular joints have been widely used in offshore platforms and space structures due to their merits such as easy fabrication, aesthetic appearance and better static strength. For existing tubular joints, a grouted sleeve reinforced method was proposed in this paper. Experimental tests on five tubular T-joints reinforced with the grouted sleeve and two conventional tubular T-joints were conducted to investigate their mechanical behaviour. A constant axial compressive force was applied to the chord end to simulate the compressive state of the chord member during the tests. Then an axial compressive force was applied to the top end of the brace member until the collapse of the joint specimens occurred. The parameters investigated herein were the grout thickness, the sleeve length coefficient and the sleeve construction method. The failure mode, ultimate load, initial stiffness and deformability of these joint specimens were discussed. It was found that: (1) The grouted sleeve could change the failure mode of tubular T-joints. (2) The grouted sleeve was observed to provide strength enhancement up to 154.3%~172.7% for the corresponding un-reinforced joint. (3) The initial stiffness and deformability were also greatly improved by the grouted sleeve. (4) The sleeve length coefficient was a key parameter for the improved effect of the grouted sleeve reinforced method.

• Earthquakes and Structures
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• 제10권1호
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• pp.53-71
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• 2016

Unconventional computer vision and image processing techniques offer significant advantages for experimental applications to shaking table testing, as they allow the overcoming of most typical problems of traditional sensors, such as encumbrance, limitations in the number of devices, range restrictions and risk of damage of the instruments in case of specimen failure. In this study, a 3D motion optical system was applied to analyze shake table tests carried out, up to failure, on a natural-scale masonry structure retrofitted with steel reinforced grout (SRG). The system makes use of wireless passive spherical retro-reflecting markers positioned on several points of the specimen, whose spatial displacements are recorded by near-infrared digital cameras. Analyses in the time domain allowed the monitoring of the deformations of the wall and of crack development through a displacement data processing (DDP) procedure implemented ad hoc. Fundamental frequencies and modal shapes were calculated in the frequency domain through an integrated methodology of experimental/operational modal analysis (EMA/OMA) techniques with 3D finite element analysis (FEA). Meaningful information on the structural response (e.g., displacements, damage development, and dynamic properties) were obtained, profitably integrating the results from conventional measurements. Furthermore, the comparison between 3D motion system and traditional instruments (i.e., displacement transducers and accelerometers) permitted a mutual validation of both experimental data and measurement methods.

• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.1290-1297
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• 2008

A pipe jacking method complements the excavation method and it is a non-excavation method which is thrust in the earth. On that score, using the pipe jacking method is increased because of constructability and economical efficiency in a medium or small-sized pipeline construction. However, a pipe jacking method still has several problems that the base ground is disturbed and loosen. Especially, where some sites have boulders, gravels and foreign bodies, the foundation is brought about deformation, settlement and leakage of water. Thus, the end of the construction the ground should be reinforced by grouting and it occur with additional expenses. Therefore, a steel pipe jacking method with grouting, Grout In Pipe, is devised newly to complement the existing method. In this study, it describes a new method and verifies efficiency, an application and practicality of the method through a experimental construction.