• Title/Summary/Keyword: reinforcing bar anchor

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Tensile Properties and Testing Method for Glass Fiber Reinforced Polymer Reinforcing bar (GFRP Rebar의 인장특성 및 시험법에 관한 연구)

  • Park Ji-Sun;You Young-Chan;Park Young-Hwan;Choi Ki-Sun;You Young-Jun;Kim Keung-Hwan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2004.05a
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    • pp.172-175
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    • 2004
  • This study is to investigate the tensile properties of glass fiber reinforced polymer(GFRP) reinforcing bars with various kinds of anchor systems experimentally. Three types of anchor systems were examined: resin sleeve anchor adopted by CSA Standard, metal overlay anchor by ASTM Standards and wedge anchor normally used in prestressing tendons. Also, three different types of GFRP bars with different surface deformations were tested in this study. All test procedures including specimens preparation, test apparatus and measuring devices were made according to the recommendations of CSA Standard S806-02. From the test results, it was found that the highest tensile strength of GFRP bar was developed by resin sleeve anchor, and tensile strength of GFRP bar with CSA anchor system is $10\%$ higher than that with ASTM anchor system in the case of sand-coated GFRP bar.

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Reinforcing Characteristics of Hybrid Fiber Composite Fixed with Impact Anchor (타격식 앵커를 이용한 하이브리드 섬유보강재의 보강특성)

  • Ha, Sang-Su;Choi, Dong-Uk;Lee, Chin-Yong;Kim, Dong-Wan
    • Proceedings of the Korea Concrete Institute Conference
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    • 2008.11a
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    • pp.453-456
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    • 2008
  • Fiber composite is high anticorrosive, high strength and low weight ratio of strength(1/4 of reinforcing bar) so that strengthens concrete structures without increase of additional weight. But fiber composite has a brittle character which increases to the maximum stress point lineally and is suddenly destroyed. Hybrid fiber composite is developed to overcome weakness of fiber composite. The hybrid fiber composite is manufactured by bar type and consists of 9:1 volume ratio(glass : carbon). In this study the result indicates that it is purposed to find out reinforcing characteristics of hybrid fiber composite fixed with impact anchor.

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Pull-out Behaviors of Headed Bars with Different Details of Head Plates (Head 플레이트 상세에 따른 Headed Bars의 인발거동에 관한 연구)

  • Park, Hyun-Gyoo;Yoon, Young-Soo;Ryoo, Young-Sup;Lee, Man-Seop
    • Journal of the Korean Society of Hazard Mitigation
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    • v.2 no.2 s.5
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    • pp.95-104
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    • 2002
  • This paper presents the pull-out failure mode on Headed Bars and prediction of tensile capacity, as governed by concrete cone failure. 17 different plate types, three different concrete strengths and three different welding types of specimens were simulated. Test variables are the reinforcing bar diameters connected to headed plate (e.g., 16mm, 19mm and 22mm), the head plate shapes (e.g., circular, square, rectangular), the dimensions of head plates (e.g., area and thickness), the types of welding scheme for connection of reinforcing bars and head plates (e.g., general welding and friction welding). Headed Bars were manufactured in different areas, which shape and thickness are based on ASTM 970-98. Calculation of Embedment length in concrete is based on CSA 23.3-94, and static tensile load was applied. Pullout capacities tested were compared to the values determined using current design methods such as ACI-349 and CCD method. If compare experiment results and existings, Headed bar expressed high strength and bigger breakdown radious than standard by wide plate area and anomaly reinforcing rod unlike anchor.

Direct Shear Test of Retrofit Anchors Using Deformed Reinforcement and Adhesive

  • Choi, Dong-Uk;Kim, Yong-Gon
    • KCI Concrete Journal
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    • v.12 no.1
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    • pp.91-99
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    • 2000
  • A new type of retrof=t anchor bolt that uses deformed reinforcing bars and a commercial adhesive was developed and then an experimental study was carried out to determine the behavior of the anchors in direct shear. The steel-to-concl몫ete interface was tested. Plain concrete slabs with about 20-MPa compressive strength were used for 23 direct shear tests performed Test variables were anchor diameters (D16, D22. and D29) and edge effect. Three different shear tests were completed: simple shear, edge shear where anchors were pulled against the concrete core, and edge shear where anchors were pushed against the concrete cover In the simple and the edge shear tests where the anchors were pulled against the core, the theoretical dowel strength determined by (equation omitted) was achieved but with relatively large displacements. The shear resistances increased with the increasing displacements. In the edge shear test where the anchors were pushrd against the cover, the peak shear strengths signif=cantly lower than the theoretical dowel strength were determined due to cracks developed in concrete when the edge distance was 80 mm. The peak strengths were about 50% of the dowel strength for Dl6 bar. and about 25% or less of the dowel strength for D22 and D29 bars. Test results revealed that the edge shear where the anchor was pushed against the cover controled.

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Static Shear Strength of Cast-in Anchors with Stirrup Reinforcement (스터럽 보강 선설치 앵커의 정적 전단하중에 대한 저항 강도)

  • Park, Yong Myung;Jo, Sung Hoon;Kim, Tae Hyung;Kang, Choong Hyun;Kim, Jae Bong
    • Journal of Korean Society of Steel Construction
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    • v.28 no.1
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    • pp.1-12
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    • 2016
  • An experimental study was conducted to evaluate the static shear strength of stirrup-reinforced cast-in anchors. The test parameters considered herein are an existence of front bearing bar and concrete crack. M36 anchor was used with an edge distance of 180mm. HD-10 bars were used for all reinforcing bars and the stirrups were placed with 100mm spacing. The shear resistance increased by 16% when the front bearing bar was installed. Meanwhile, the resistance reduced only 5% in the cracked concrete compared with the uncracked concrete. The test results showed that ACI 318 and ETAG 001 specifications could estimate the shear strength of stirrup-reinforced anchors conservatively and a rational method was proposed. A consideration on the fracture strength of stirrup-reinforced anchor is also given.

Numerical Simulation of Arch-type Submarine Cable Protector under Anchor Collision (아치형 해저 케이블 보호 구조물의 앵커 충돌 수치 시뮬레이션)

  • Woo, Jin-Ho;Na, Won-Bae;Kim, Heon-Tae
    • Journal of Ocean Engineering and Technology
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    • v.23 no.1
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    • pp.96-103
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    • 2009
  • In 2006, Jeju Island in South Korea experienced a crisis, no electricity for three hours anywhere in the entire island. This incident was caused by a domino effect that occurred after one of the submarine power cables connecting the island to Haenam, a coastal city on the mainland, was damaged by an external load, probably from a ship anchor or a steel pile being used in marine farming. This study presents a collision analysis of a new submarine power cable protector called arch type reinforced concrete. For the analysis, a dynamic finite element program, ANSYS AUTODYN, was used to examine the displacement and stress of the submarine power cable protector using different material models (RHT concrete model, Mohr.Coulomb concrete model). In addition, two reinforcing bar spacings, 75 mm and 150 mm, were considered. From the analyses, the effects of the parameters (concrete model and spacing) on the results (displacement and stress) were analyzed, and the relations between the damage and parameters were found.

A new base plate system using deformed reinforcing bars for concrete filled tubular column

  • Park, Yong-Myung;Hwang, Won-Sup;Yoon, Tae-Yang;Hwang, Min-Oh
    • Steel and Composite Structures
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    • v.5 no.5
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    • pp.375-394
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    • 2005
  • An experimental study was conducted to develop a new base plate anchorage system for concrete filled tubular column under an axial load and a moment. The column was connected to a concrete foundation using ordinary deformed reinforcing bars that are installed at the inside and outside of the column. In order to investigate the moment resisting capacity of the system, horizontal cyclic loads are applied until the ultimate condition is reached with the axial load held constant. To derive a design method for moment resisting capacity, the reinforced concrete section approach was investigated with the assumption of strain compatibility. The results by this approach agreeded well with those of experiments when the bearing pressure of confined concrete and tangent modulus of steel bars are assumed appropriately. Also, it was found that the column interaction curve can be used to predict the yield strength of the base plate system.

Strengthening Effects of R.C. Beams using Externally attached CFRP Composites with Bond[ Details (CFRP로 보강된 RC보의 부착상세에 따른 보강효과)

  • 박종섭;박영환;조정래;유영준;정우태
    • Proceedings of the Korea Concrete Institute Conference
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    • 2003.05a
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    • pp.591-596
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    • 2003
  • Many studies have dealt with strengthening by epoxy-bonded CFRP(Carbon Fiber Reinforced Polymer) composites. However, the effects of various influencing factors have not been clarified on the behavior of strengthened RC beams. This study was performed to verify the effects of strengthening due to various bond details of externally attached CFRP Composites. In this study, major test parameters include the bond type and the anchor type. The deflections, failure load, strain of reinforcing bar, concrete and CFRP are measured at each loading step. The failure mode and debonding loads(ultimate loads) are analysed from these measured data. According to the test results, all specimens are failed by intermediate flexural crack induced interfacial debonding.

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Structural Behavior of RC Beam Strengthened with Steel Plate (강판 휨보강된 철근 콘크리트보의 구조적 거동)

  • 오병환;강동욱;조재열;채성태;이명규
    • Proceedings of the Korea Concrete Institute Conference
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    • 1997.04a
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    • pp.598-604
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    • 1997
  • In recent years, strengthening by epoxy-bonded steel plates, carbon fiber sheets, aramid fiber sheets and so on, is spotlighted. Among them, the method using steel plates is most widely applied. Most studies have dealt with strengthening by epoxy-bonded steel plates. However the actual behavior of strengthened RC beams are not well established. Particularly, the studies on the separation load thar affects failure load of the beam are relatively insufficient. In this study, test parameters are the magnitude of pre-load, plate length, plate thickness, existence and spacing of anchor bolt, the number of plate layer and the height of side strengthening, 17reinforced concrete beams are strengthened by steel plates according to test parameters. Deflection, failure load, strains of reinforcing bar, concrete and plate are measured from tests(4 points loading). The failure mode, and separation load are analyzed from these measured data. The difference between Robert's theory and test results is discussed, and the prediction equation for separation load in the case of rip off is proposed.

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Survey Research on Thermal Situation of Office Buildings (사무소 건축물의 단열상황에 관한 조사연구)

  • Jung, Ui In;Kim, Bong Joo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.3
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    • pp.145-152
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    • 2013
  • This study is to evaluate the thermal insulation of the curtain wall of the buildings constructed since the 1990s to the buildings currently under construction in 2011 and to provide the basic data for repairing and reinforcing and designing the thermal insulation. To this effect, the temperature difference by part was analyzed through measuring the inside and outside surface temperature of the curtain wall of the office building, and thereafter, the conditions of the thermal insulation and the thermal bridge part were examined. The result of the study is as follows; Not only in the winter season when the temperature difference between the indoor-outdoor is over $20^{\circ}C$, but also in the summer season when there is a small temperature difference, the temperature difference between the inside and outside of the frame is $2^{\circ}C{\sim}4^{\circ}C$ equally. Under such conditions as stated above, the thermal bridge occurred, which resulted from the heat flow of the steel frame part (mullion, transom), and therefore, the reinforcement of the thermal insulation is considered to be needed.