• 한국구조물진단유지관리공학회지
• /
• 제18권1호
• /
• pp.14-19
• /
• 2014

• 한국건강관리협회지
• /
• 제3권2호
• /
• pp.189-198
• /
• 2005

This study examined the applicability of the transtheoretical model(TTM) to understanding exercise behavior of early adulthood. A cross-sectional study was conducted and data wee collected from 1618 adults aged from 20 to 39 through internet survey. Major conclusions wee as follows: 1. Stage distribution for exercise behavior was 15.6%, 26%, 25%, 19%, 14.4% for precentemplation, contemplation, preparation, action, maintenance stages, respectively. 2. Behavioral processes were more frequently utilized than cognitive processes for action and maintenance stage. 3. Self-reevaluation, social liberation and reinforcement were frequently used in precontemplation, contemplation and preparation stages. Self-reevaluation, reinforcement, self-liberation were frequently used in action and maintenance stages. 4. Pros of exercise behavior began to be higher than cons of exercise behavior from the actions stage and continued to increase to maintenance stage. 5. Self-efficacy was higher in action stage than precontemplation, contemplation and preparation stages and the highest in maintenance stage.

• 한국구조물진단유지관리공학회지
• /
• 제18권2호
• /
• pp.60-63
• /
• 2014

• 한국구조물진단유지관리공학회 논문집
• /
• 제6권2호
• /
• pp.203-210
• /
• 2002

In these days, High-strength steel prevails throughout the construction fields for the benefit of structural and economical aspects. But high-strength steel is used by the simple calculation of flexural capacities for the purpose of reducing flexural reinforcement. So, this paper is mainly focused on the shear behavior of high-strength steel reinforced concrete beams without stirrups comparing with normal-strength steel reinforced concrete beams. Specimens were made and tested with the experimental parameters, such as steel yield strength, reinforcement ratios and minimum shear reinforcement. The main result was that not only area but also the yield strength of flexural reinforcement should be considered to predict the shear capacities of concrete beams. In addition, the experimental results were simulated by modified compression field theory analysis program, RESPONSE 2000. A good agreement was achieved between the test results and program analyses.

• 한국구조물진단유지관리공학회 논문집
• /
• 제2권3호
• /
• pp.188-193
• /
• 1998

An experimental study was performed on the pull-out behavior of 90-deg standard hooks from exterior beam-column connections. The effects of lateral confinement and fiber reinforcement of joint area were investigated. It was concluded ; (1) Substitution of the transverse column (confining) reinforcement with steel fibers at the joint region effectively reduces the extent of cracking in exterior joints caused by pull-out of hooked bars; and (2) The strength and ductility of hooked bars under pull-out forces are positively influenced by substituting the conventional confining reinforcement of exterior joints with steel fibers. Application of steel fibers to exterior joints seems to be an effective technique for improving the anchorage conditions of hooked bars, and also for reducing the congestion of reinforcement in exterior beam-column connections.

• 한국구조물진단유지관리공학회 논문집
• /
• 제25권2호
• /
• pp.49-57
• /
• 2021

본 연구에서는 특수 전단벽 연결보의 배근 상세를 개선하여 구조 성능의 확보는 물론 시공성을 개선한 연구를 진행하였다. 기존 대각선 다발철근과 전단 보강근을 배근한 실험체를 기본으로 이를 굵은 대각철근으로 교체한 실험체, 수평 보강근으로 교체한 실험체를 변수로 선정하였다. 실험결과 기존 대각보강근을 굵은 직경의 철근으로 대체한 실험체가 기본 실험체와 유사한 거동을 보여 복잡합 연결보 보강 상세의 대안으로 적용 가능한 것으로 평가되었다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제5권1호
• /
• pp.228-236
• /
• 2001

When RC beams are strengthened for flexure with steel plate, reinforced member has initial strain due to the dead load and is subject to partial damage. Strain of steel strengthening is zero at initial state. The effect of strengthening flexural member might be influenced by the quantity of initial strain. In this study, when He beams are strengthened for flexure with steel plate, its behavior is experimentally compared for the reinforcement efficiency of members due to the existence of different levels of initial strain. It is confirmed that reinforcement efficiency varies depending on the difference of initial strain.

• 한국구조물진단유지관리공학회 논문집
• /
• 제18권1호
• /
• pp.48-58
• /
• 2014

본 연구에서는 1992년 도로교설계기준의 내진설계도입 이전 규정에 따라 설계, 시공된 교각의 축소 모델을 실험체로 제작하여 원형기둥의 변위비에 따른 횡하중을 변위제어 방식으로 입력하여 준정적 방법을 통해 실험을 실시하였다. 연구에 적용한 보강재는 성능을 향상시킨 무기계 합금강인 Helical Bar로써 원형기둥 외부에 보강 후 실내실험을 통하여 파괴거동, 하중-변위 관계, 연성도 평가 및 에너지 평가를 실시하였다. 실험변수로는 위험단면 내에서 나선으로 보강한 보강재의 단면력의 크기와 나선보강의 간격, 보강형태로 두었으며, 준정적 실험을 통해 보강성능의 차이와 효과를 확인하였다. 실험결과 보강대상 부재의 성능에 따라 적절한 보강재의 단면력 크기결정과 보강간격 및 형식의 선정이 필요하며 기계적 보강재뿐만 아니라 고강도 콘크리트 피복으로의 치환으로도 보강성능이 향상됨을 확인할 수 있었다.

• 한국구조물진단유지관리공학회 논문집
• /
• 제6권4호
• /
• pp.233-242
• /
• 2002

This study is to investigate experimentally the shear capacity of high-strength lightweight-aggregate reinforced concrete beams subjected to monotonic loading. Ten beams made of fly-ash artificial lightweight high-strength concrete were tested to determine their diagonal cracking and ultimate shear capacities. The variables in the test program were longitudinal reinforcement ratio; which variabled (between 0.83 and 1.66 percent), shear span-to-depth ratio (a/d=1.5, 2.5 and 3.5), and web reinforcement(0, 0.137, 0.275 and 0.554 percent). Six of the test beams had no web reinforcement and the other six had web reinforcement along the entire length of the beam. Most of beams failed brittly by distinct diagonal shear crack, and have reserved shear strength due to the lack of additional resisting effect by aggregate interlocking action after diagonal cracking. Test results indicate that the ACI Building Code predictions of Eq. (11-3) and (11-5) for lightweight concretes are unconservative for beams with tensile steel ratio of 1.66, a/d ratios greater than 2.5 without web reinforcement. Through a more rational approach to compute the contribution of concrete to the shear capacity, a postcracking shear strength in concrete is observed.

• 한국구조물진단유지관리공학회 논문집
• /
• 제18권1호
• /
• pp.75-83
• /
• 2014

콘크리트의 취성파괴를 방지하기 위해 강섬유 보강재는 효과적인 복합재료이다. 그러나 시멘트 사용량이 많아지면 건조수축이 증가하고 이로 인해, 강섬유 보강재의 연성증가 효과가 제한될 수 있다. 팽창재를 사용한 콘크리트 내부의 강섬유 보강재는 화학적 프리스트레싱 효과가 발생하여 강섬유 보강효과를 증가시킬 수 있다. 본 연구에서는 CSA 팽창재와 강섬유 보강재를 혼입하여 콘크리트의 역학적인 특성을 분석하였다. 체적비 1~2%의 강섬유 보강재와 시멘트 중량의 10%의 CSA 팽창재를 혼입하였으며, 다양한 역학적 특성과 휨거동을 분석하였다. 강섬유 보강재를 혼입한 CSA 콘크리트는 인장강도와 초기균열강도의 증가를 나타냈으며, 균열후의 파괴에너지 증가와 같은 연성거동을 뚜렷하게 나타내었다. 적절한 팽창재 사용과 최적의 강섬유 보강재의 혼입률이 도출된다면 이들의 상호작용은 콘크리트의 취성을 더욱 효과적으로 제어할 수 있다.