• 제목/요약/키워드: external strengthening

검색결과 305건 처리시간 0.025초

Plate로 전면보강된 교량 상판의 거동특성에 관한 연구 (A Study on the Structural Characteristic of Strengthened Bridge Deck Specimens Using External Bonded Plate)

  • 심종성;오홍섭;김언경
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2001년도 봄 학술발표회 논문집
    • /
    • pp.163-168
    • /
    • 2001
  • Punching shear in concrete slabs is a serious problem in certain structural systems, such as flat slab. In this study, mechanical improvement between specimens which are unstrengthened and strengthened with steel plate and fiber panel is experimentally investigated. The strengthened bridge deck specimens had increment of strength and broke down with punching shear failure. Strengthening ratio should be considered to restraint punching failure.

  • PDF

자기진단 재료로서의 콘크리트 보강용 탄소유리복합섬유로드의 적용성 검토 (Self Diagnosing Property of Carbon and Glass Hybrid Fiber Materials for Concrete Strengthening)

  • 박석균;이병재
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
    • /
    • pp.428-431
    • /
    • 2004
  • Smart structural system is defined as structural system with a certain-level of autonomy relying on the embedded functions of sensors, actuators and processors, that can automatically adjust structural characteristics, in response to the change in external disturbance and environments, toward structural safety and serviceability as well as the extension of structural service life. In this study, carbon and glass hybrid fiber materials were investigated fundamentally for the applicability of self diagnosis in smart concrete structural system as embedded functions of sensors.

  • PDF

탄소섬유 보강판(CFRP)으로 보강된 철근콘크리트보의 강성예측에 관한 연구 (The Study of the Strength Prediction of RC Beam with Externally bonded Carbon Fiber Reinforced Plate)

  • 한상훈;최홍식;홍기남;신동주
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2000년도 봄 학술발표회 논문집
    • /
    • pp.763-768
    • /
    • 2000
  • The purpose of this paper is to predict the flexural strengthening of reinforced concrete beams by the external bonding of carbon fiber reinforced plate(CFRP) to the tension face of the beam. Used computational equation is derived by relation of stress an strain. This equation is applied to four-nondamage beam and tow-preloading beam. Six scale beams were tested to evaluate the strength enhancement provided by the CFRP. And describes the strength enhancement provided to the flexural capacity of reinforced concrete beam by the external bonding of CFRP. An inelastic section analysis procedure was developed that accurately predicts the load displacement response of the retrofitted beams.

  • PDF

외부 긴장 보강을 위한 탄소섬유 복합재료용 쐐기형 정착구 거동 (Behavior of Wedge-Type Anchor System for External Prestressing Method with CFRP)

  • 신재민;정대성;정우태;박종섭;박영환;김철영
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
    • /
    • pp.477-480
    • /
    • 2004
  • This paper present test result to develop wedge-type anchor system for external prestressing method with CFRP. The test results indicated that the lower a slope angle and elastic of wedge are, the higher ultimate strengths are for plate types. Bar types showed premature failure because of local high stress in FRP of anchor system. Therefore, to improve the strength for bar types needs further work of strengthening sleeves, slope angles of wedge and materials.

  • PDF

고장력 인장봉으로 보강된 RC보의 휨거동에 관한 실험적 연구 (An Experimental Study on the Flexural Behavior of RC Beams Strengthened with Hi-Strength Bars)

  • 김윤정;신경재;문정호;오영석
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2006년도 추계 학술발표회 논문집
    • /
    • pp.193-196
    • /
    • 2006
  • Unlike external bonded plate or carbon fiber, the external unbonded strengthening has some advantages in speed and simplicity of installation. It is not required surface preparations and not affected by environmental conditions. A set of six laboratory tests on RC beams strengthened using the technique are reported, results compared with non-strengthened specimens. The main test parameters are the cross-sectional area of the high-tension bar and the distance of stirrups. Test result show that the beams reinforced are superior to reference specimens, especially for the strength and deformation capacity. Also, it is shown that good efficiencies can be achived in shear strength of the beam.

  • PDF

외부치장적벽돌 벽체에 대한 콘크리트 보강브라켓의 보강효과에 관한 연구 (A Study on the Strengthening effect of Concrete Reinforcement Bracket on the External Clay Brick Wall)

  • 김선우;김양중
    • 한국건축시공학회:학술대회논문집
    • /
    • 한국건축시공학회 2020년도 봄 학술논문 발표대회
    • /
    • pp.117-118
    • /
    • 2020
  • The masonry structure is constructed by cement mortar binding material of brick objects and uses reinforced hardware (connected hardware or wall tie) together when building. However, over time, the corrosion of reinforced steel and the deterioration of joint mortar as well as bricks cause the risk of collapse. In particular, when the externally decorated brick wall is installed on the concrete girder for each floor, the angle bracket is not constructed or corroded, the full-layer weight load is applied to the wall of 0.5B, which is an example of full-scale or collapse. The purpose of this study is to provide numerical information on the reinforcement design by experimentally studying the structural performance of concrete reinforcement brackets that reinforce the vertical load of the exterior wall.

  • PDF

감사의견(監査意見)의 추이요인(推移要因)에 관한 연구(硏究) (A Study on Transition Factor of Audit Opinion)

  • 정연해
    • 경영과정보연구
    • /
    • 제7권
    • /
    • pp.141-168
    • /
    • 2001
  • The causes that the transparency of Korean accounting information was rated low, a short supply of faithful and transparent accounting information from the limitation of external audit environment must be pointed out. Purpose of the external audit is a expression of the auditors about that financial statements an enterprise made public were appropriately drew up in accordance with the corporate accounting principles from important point of view. Analysis of the audit opinion and so fourth according to 6,541 individual audit reports and introduced to the bill securities forward committee as a subject of external audit according to the raw of corporation external audit show that considerable change to the contents of audit report. This show as it is that uncertainty of future that is now being faced by our enterprise, because corporation which present audit reports since 1997 because of enterprise dishonor and contents of existence probability as a continued enterprise following to general economic crisis after 1998 occupy important position in special matters of audit report. Also, increase in special matters is due to application of the corporate accounting principles revised on December 11, 1998. In 1999, audit opinion under limitation(limitation, incongruity and rejecting opinion) increased greatly according to existence doubt as a continued enterprise, and this is the consequence of strengthening audit to the continues enterprise because of limited enterprise dishonor according to the stagnancy of business activities after 1997. Now financial supervisory service put in effect electromagnetic public announcement system about a project report of listed corporation (including an audit report) keeping pace with a documentary public announcement system as first phase since 1999 and expand to the unlisted corporation from 2000. As electromagnetic public announcement of public announcement documents including audit documents of external audit subject get a duty, approach of external user to the accounting information will be easier. Fixation of this system will make deep and wide analysis to the audit opinion, and this will draw up a plan to reconsider confidence of accounting information.

  • PDF

엎드려 무릎관절 굽힘 자세에서 엉덩관절 폄 동작 시 무게 부하 변화에 따른 큰볼기근과 넙다리두갈래근의 두께 비교 (A Comparison of Gluteus Maximus Muscle and Biceps Femoris Muscle Thickness According to Weight Load during Prone Hip Extension with Knee Flexion Exercises)

  • 장은미;정다은
    • PNF and Movement
    • /
    • 제21권3호
    • /
    • pp.309-317
    • /
    • 2023
  • Purpose: This study set out to investigate the effects of prone hip extension with knee flexion (PHEKF) exercises according to external load on the thickness of the gluteus maximus (Gmax) and biceps femoris (BF). Methods: Twenty-three healthy men participated in this study. All subjects randomly practiced PHEKF under the burden of external loads created by sandbags (0 kg, 1 kg, and 2 kg). Rehabilitative ultrasound imaging (RUSI) was used to measure the thickness of the Gmax and BF during the PHEKF with different external loads. Results: The thickness of the Gmax was highest during the 2 kg resistance exercise and lowest at 0 kg. The thickness of the Gmax was significantly increased at 1 kg and 2 kg compared to 0 kg and significantly increased at from 1 kg to 2 kg (p < 0.05). The thickness of the biceps femoris was highest at 0 kg and lowest at 2 kg. The thickness of the biceps femoris muscle was significantly reduced at 1 kg and 2 kg compared to 0 kg (p < 0.05), but there was no significant difference between 1 kg and 2 kg (p > 0.05). Conclusion: The thickness of the Gmax was increased by applying PHEKF with a higher external load, whereas the muscle thickness of the biceps femoris decreased. These results suggest that the application of external loads during PHEKF exercises may be an effective method for selective strengthening of the Gmax.

외부벽체 강도증진형 보강이 적용된 비보강 조적조 건물의 내진성능평가 (Seismic Performance Evaluation of Unreinforced Masonry Buildings Retrofitted by Strengthening External Walls)

  • 설윤정;박지훈
    • 한국지진공학회논문집
    • /
    • 제24권2호
    • /
    • pp.77-86
    • /
    • 2020
  • Nonlinear static analysis and preliminary evaluation were performed in this study to evaluate the seismic performance of unreinforced masonry buildings subjected to various soil conditions based on the revised Korean Building Code. Preliminary evaluation scores and nonlinear static analyses indicated that all buildings were susceptible to collapse and did not reach their target performance. Therefore, retrofit of those building models was carried out through a systematic procedure to determine areas to be strengthened. It was possible to make most building models satisfy performance objectives through the reinforcement alone of damaged external shear walls. However, the application of a preliminary evaluation procedure to retrofit design was found to be too conservative because all the retrofitted building models verified with nonlinear static analysis failed to satisfy performance objectives. Therefore, it is possible to economically retrofit unreinforced masonry buildings through the fortification of external walls if a simple evaluation procedure that can efficiently specify vulnerable parts is developed.

개방형 혁신여건 조성을 통한 정부 R&D투자의 성과 제고 (Performance Improvement of Government R&D Investments Through Creating Open Innovation Conditions)

  • 김재홍
    • 디지털융복합연구
    • /
    • 제8권2호
    • /
    • pp.29-42
    • /
    • 2010
  • 그동안 정부는 R&D투자의 성과 제고를 위해 R&D 시스템 내의 구조와 프로세스를 개선하는데 많은 노력을 기울여 왔다. 그러나 대내외 기술 환경이 급변하고 투자규모가 지속적으로 증가함에 따라, 정부 R&D 또한 다양한 외부자원의 활용을 통해서 규모의 수확을 이룰 수 있는 혁신적인 접근방법이 필요한 상황이다. 이러한 관점에서 '개방형 혁신'은 외부자원에 대한 흡수능력 (absorptive capacity)을 향상시키고, 다양한 혁신주체 간 협력과 참여를 제고시킬 수 있다는 점에서 '정부실패'의 가능성을 최소화 시킬 수 있다. 본 논문은 정부 R&D투자의 성과에 관한 선행연구와 정부정책을 평가하고, 개방형 혁신이 정부 R&D투자의 성과 제고에 기여할 수 있는 연계성을 보여주고 있다.

  • PDF