• Proceedings of the Korea Concrete Institute Conference
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• 2008.11a
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• pp.859-862
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• 2008

The objective of this study offer the equation of the development length for GFRP reinforcement. Pullout test carried out to propose the development length for GFRP reinforcement. Test variables included embedment length (L=15, 30 and 45d$_b$ ), pure cover thickness(C=0.5, 1.0, 1.5, and 2.0d$_b$ ), diameter of reforcement(D10, D13 and D16), and three types, (domestic : K2KR, K3KR, foreign : AsUS) of GFRP reinforcement. The method of test were introduced pure pullout and tests lasted until the GFRP reinforcements were reached final failure. Based on the results through the pullout test, the bond characteristics and average bond stress for GFRP reinforcement were investigated. The equation of development length was proposed based on the regression analysis selected specimens having splitting failure. The equation gained from this study compared with the design equation provided by ACI committee 440.1R-06. The results through this study are capable of the flexural member design with GFRP reinforcement having lab spliced.

• Journal of the Korea Institute of Building Construction
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• v.9 no.6
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• pp.141-149
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• 2009

The objective of this study was to propose a development length equation for bottom and top GFRP bars. Including the bottom and top GRPP bars, a total of 104 modified pullout tests were completed. The test variables were embedment length (15, 30, 45db), net cover thickness (0.5~2.0db), different GFRP bar types, and bar diameters (10, 13, 16mm). The average bond stresses were determined based on the modified pullout test results. Two variable linear regression analyses were performed on the results of the average bond stresses. Utilizing the 5% fractile concept, a conservative development length design equation was derived. The design equation of the development length for bottom and top GFRP bars was proposed and the design equation derived in this study was compared to the ACI 440.1R-06 committee equation.

• Journal of the Earthquake Engineering Society of Korea
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• v.13 no.1
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• pp.9-16
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• 2009

For reinforced concrete members, bond strength is one of the important factors between the two materials: the concrete and the reinforcing element. The bond strength of Aramid Fiber Reinforced Polymer (AFRP) rebar was tested using the pull-out method. Presented were comparison results of the bond strength between AFRP rebar and deformed steel bars from the test. Embedded lengths and diameters of the rebar were taken into account as parameters. The bond stress-slip responses and failure modes of AFRP rebar were evaluated. It was found that the bond stress-slip responses of AFRP rebar were similar to those of deformed steel bars. As the diameter of rebar increased, the pull-out load increased. In addition, it was shown that the bond strength of an AFRP rebar was approximately 54% compared with that of a deformed steel bar.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.15 no.4
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• pp.2428-2435
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• 2014

Numerical analysis with ALE (Arbitrary Lagrangian Eulerian) Adaptive Meshing technique was performed to evaluate the pullout capacity of the embedded suction anchors (ESA) in uniform clay. The numerical method was verified by the previous study, analytical results based on limit-equilibrium theory and centrifuge tests. The pullout capacity of the ESA under horizontal, vertical, and inclined loading were evaluated, and the effect of initial rotation of the ESA on pullout capacity was also investigated. The analysis results showed that the maximum horizontal capacity was obtained at the mid-point, and the each vertical capacity gave the similar value regardless of the loading points. Furthermore, the inclined capacity was decreased as the load inclination angle increased at the mid-point of the anchor, and almost the same pullout capacity was obtained when the initial rotation angles were below 30 degrees.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.167-173
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• 2014

The embedded suction anchor, ESA, is one type of mooring anchor systems which utilizes the suction pile or caisson to penetrate the anchor into the sea bed and develops its capacity under pullout load. In this study, the numerical analysis using ALE (Arbitrary Lagrangian Eulerian) Adaptive Meshing technique was performed to simulate the pullout behavior of the ESA, and the results were compared to those of the previous research, centrifuge model tests and the analytical method based on limit equilibrium theory. The pullout behaviors of the ESA under horizontal, vertical, and inclined loading were evaluated. The analysis results showed that the maximum horizontal pullout load was developed when the location of loading point was at the mid-point, and the each vertical pullout load gave the similar value regardless of the locations of the loading points. The pullout load decreased as the load inclination angle increased at the mid-point of the anchor.

• Journal of the Korea Organic Resources Recycling Association
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• v.21 no.4
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• pp.50-61
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• 2013

In order to generate a renewable energy-Methane, anaerobic systems fed with source separated food waste from university cafeteria were studied. At first, four reactors were evaluated with same feed components; content non-mixing anaerobic reactor without leachate withdrawal/recirculation, content mixing anaerobic reactor without leachate withdrawal/recirculation, content non-mixing anaerobic reactor with leachate withdrawal/recirculation and content mixing anaerobic reactor with leachate withdrawal/recirculation. From the first study, content non-mixing anaerobic reactor with leachate withdrawal/recirculation showed the highest gas production. From further study with this system, it was observed that leachate permeation rate within anaerobic reactor was very important factor for gas generation. The higher permeation rate, the more gas production was observed. It is assumed that 1kg of gas collector weight and C/N ration above 10 in food waste may cause gas consumption in the anaerobic reactor. The gas consumption was estimated by negative pressure build-up at gas collector. The negative pressure build-up must be explained to produce Methane from Food Waste.

• Journal of the Korean GEO-environmental Society
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• v.4 no.1
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• pp.67-75
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• 2003

In this study, the steel strip reinforcement bolted with braced angles expected to mobilize skin friction resistance as well as bearing resistance is proposed. Laboratory pullout tests are conducted to investigate the characteristics of pullout behavior. From the test results, friction effects between soil and reinforcement are evaluated with the width of reinforcement, magnitude of surcharge, and existence of bearing resistance member. Further to analyze interference effects for bearing resistance member, pullout tests are also carried by varing the number, the location, and the spacing of braced angles. Based on the test results, pullout resistance factor is evaluated under the consideration of location of braced angles and the degree of interference for spacing ratio.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.29-30
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• 2009

In this study, analyzing loads transferred to the piles, both easily constructed and mechanically improved pile head design method for the PHC pile is presented. To compare with mechanical capacity of the existing and proposed method, tensile, compression, moment, and shear tests are performed with 11 pieces of full-scaled blocks. As a result, mechanical capacities of the proposed method is superior to those of existing one in all aspects and work efficiency as well.

• Proceedings of the Korea Concrete Institute Conference
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• 2010.05a
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• pp.49-50
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• 2010

This study focuses on the bond performance of ribbed type of GFRP rebar to concrete at high temperature and discusses the results of pullout test. Pullout tests of ribbed type of GFRP rebars embedded in concrete were conducted to obtain an accurate bond stress-slip curves and also to closely observe the state of the surface of pulled-out rebars at failure. The effect of temperature on the bond strength is mainly discussed in this paper. Relatively high bond strength was seen in the control specimen which is exposed to room temperature. But, as the internal temperature increases, the bond strength decreases.

• Proceedings of the Korean Geotechical Society Conference
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• 2001.10b
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• pp.31-42
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• 2001

다양한 방식으로 제작된 유리섬유 강화 플라스틱관(FRP pipe)의 인장 및 휨강도 시험 결과로부터 제작방식에 따른 FRP관의 강도 특성을 비교 검토하였다. 또한, 사면보강대책으로서 FRP 그라우팅 공법의 현장 적용성을 평가하기 위하여, FRP 그라우팅에 따른 지반강도의 증진효과 및 보강재의 인발저항력을 산정하였다. 이를 위하여, 지반의 상대밀도 및 구속압에 따른 보강재 인발저항력의 변화 및 압력주입에 의한 확공효과 평가를 위하여 실내모형실험이 이루어졌다. 또한, FRP 그라우팅이 시공된 현장에서 공내재하시험, 투수시험, 그리고 시추공전단시험 등을 실시하여 FRP 그라우팅에 의한 지반보강 효과 및 차수효과를 정량적으로 산정하였다.