본 연구에서는 국내에서 사용되고 있는 우레탄계, 세라믹계, 폴리실록산계 및 불소수지계 강교량용 도장계를 대상으로 실내 부식실험을 실시하여 도장계별 노화모델을 도출하였다. 상도를 구분하여 각 도장계별로 시험편을 제작하였으며, 직경 0.5, 1, 3, 5 mm의 원형 결함을 도입하였다. ISO 20340를 이용하여 극한환경을 모사한 부식촉진실험을 실시하였다. 도장계별 노화곡선은 원형결함의 노화면적을 기준으로 평가되었다. 노화곡선을 사용하여 공용중인 강교의 도장 사용수명을 평가하기 위하여 촉진배율을 산출하였으며, 촉진배율은 ISO 20340과 ISO 9223의 대기환경 부식속도를 기준으로 산출되었다. 실험결과, 노화진전속도는 원형결함의 크기와 상관없이 증가하였으며, 노화면적이 3%일 때 우레탄 도장계의 노화수명은 C2, C3, C4 및 C5 등급에서 약 31.8, 15.8, 9.9 및 3.9년으로 평가되었다.

The durability of the steel structure can be affected by atmospheric corrosion environments as temperature, humidity, airborne salt etc.. However, atmospheric corrosion environments can be locally changed depending on structural condition and shape. To estimate the local atmospheric corrosion environments depending on structural member exposed to the marine environment, corrosion level of structural member in steel bridge was examined from exposure tests.

Steel water gate can be vulnerable to corrosion problem, since it is generally contacted with water or maintained with relatively high humidity condition. In this study, to evaluate the level of corrosion damage of water gate, corrosion exposure test was conducted using monitoring steel plate and monitoring sensor in actual steel water gate. From exposure test results, corrosion rate and corrosion environment were examined depending on the height or the structural type of water gate.

This study suggested the estimation method of the ground response spectra at a structure location using earthquake acceleration data from seismological observatories. To suggest estimation method based on measured earthquake acceleration data, a algorithm for determining the observations near the structure site was suggested and a module for calculating a ground response spectrum was developed associated with a listed station determining algorithm.

This study examined lateral load behaviors of partially grout filled steel tube from structural analysis. To evaluate structural resistant behaviors of partially grout filled steel tube, Nonlinear FE analysis model of partially grout filled steel tube was considered using ABAQUS program. From FE analysis results, grout filling effect and thickness effect of steel tube on the lateral load behaviors were compared.

The maintenance cost is rapidly increasing due to the increased of infrastructures such as railway and port etc., it is necessary management method of facility for measures and extend life. In the case of international infrastructure, in order to asset management to reasonably and effectively, asset management systems were developed for the management of facilities in various countries such as Australia and Canada etc. In this study, to develop the asset management process, the question investigation was conducted on maintenance site personnels for maintenance of the steel structure.

For steel structure, corrosion problem can be a major maintenance area. Even with the same steel structure, corrosion damage can be changed depending on the location and form of thes structural member. In this study, rherefore, In order to evaluate the relative corrosion enviornmnet depending on the installed condition of the structural steel member, the corrosion deterioration environment was monitored for the large-size steel frame structure.

Corrosion durability of steel member can be related to its installed environmental conditions such as relative humidity, rainfall, atmospheric temperature, and air pollution(SO2, chloride). Also its installed environmental condition may differ depending on the shape of structural member. Therefore, In this study, to evaluate the difference in the corrosion damage according to the installation environment of steel structural members, outdoor exposure test was carried out from attaching unpainted monitoring plate and atmospheric corrosion monitoring sensor for actual steel bridge with various structural detail.

Painting system are widely used to prevent corrosion damage The coating method on various corrosion preventive method was usually adopted for the functional ability and excellent appearance. In this study, to evaluate the deterioration curve of coating system for steel bridge, the combined cyclic corrosion test was conducted base on ISO 20340. The deterioration areas were measured depending on corrosion cycle. The deteriorations of newly-built coating were compared with those of re-coating.

This study examined structural behaviors of grout filled composite steel tube member, since grout-filled steel tube can improve its structural load resistance from enhancing strength, stiffness, and confining effect. To evaluated the effect of grout filling in the steel tube on its structural behaviors and strength, grout-filled steel tube specimens were fabricated and lateral loading tests were conducted. From lateral loading tests, their lateral loading resistance and stiffness were examined.

대형 용접 구조물에 대한 피로설계 수명의 예측은 일반적으로 Palmgren Miner과 등가손상도 방법 또는 선형누적손상도 방법을 사용한다. 또한 용접 구조물에서 피로 균열이 발생되면 잔존 수명은 S-N 곡선과 선형 파괴역학에 기초하여 예측되고 있다. 본 연구에서는 면외거 셋 용접이음의 3차원 피로균열 진전거동과 피로수명을 예측하기 위하여 피로 시험을 실시하였다. 면외거셋 용접이음의 3차원 피로균열진전 해석은 NX NASTRAN 및 FRANC3D를 이용하여 유한요소 해석을 실시하였다. 면외거셋 용접이음의 균열 형상비, 초기균열 크기 및 응력비에 미치는 영향을 검토하기 위하여 피로균열진전 해석을 실시하였다. 또한 초기균열크기, 균열 형상비와 응력비의 변화에 따른 3차원 피로균열진 전 해석 결과와 피로시험결과를 비교하였다. 피로균열진전 해석결과, 피로균열 진전속도와 응력확대계수와의 관계에서 피로시험과 유사하게 나타남을 확인하였으며, 면외거셋 용접이음의 피로수명을 추정할 수 있음을 확인하였다.

강교량은 유지관리가 충분히 이루어지지 않거나 , 해안 과 같이 가설위치의 환경이 고온 다습한 경우 단면에 국부적인 부식손상이 발생할 수 있다. 특히 강거더 교량 의 지점부에서는 교대부와 강거더 단부의 공간이 협소하여 상대적으로 습도가 높고 신축이음부로부터의 강 우 및 동결 방지제가 누수되어 침전물을 습윤상태로 유지하게 되므로, 복부판과 지점부 보강재에 집중적으로 부식이 발생되고 있으므로 이로 인한 구조성능 변화를 확인하여야 한다. 따라서 본 연구에서는 실제 발생할 수 있는 강거더 단부 복부판과 보강재의 국부부식손상을 모사한 강 재 실험체를 제작하고 이에 대한 단부 지압강도 변화를 실험적으로 평가하였다. 실험결과, 국부적 부식손상은 강거더 단부의 지압강도에 영향 을 주며, 특히 수직 보강재에 의한 영향이 크게 나타남을 확인하였다.

Steel structures have been prevented from corrosion damage using by paint coating. The durability of paint coating can be changed by installed environment condition of steel structures. In this study, thus, deterioration test of paint coating was conducted for various environmental condition. Deterioration levels of paint coating specimens exposed by each artificial environment were examined from visual inspection.

Recently, steel has been very frequently chosen in building many civil infra-structures including bridges due to its several beneficial advantages as compared to concrete structures. However, for the most cases, damage such as section reduction, that is resulted from corrosion, was natural and inevitable. Therefore, it becomes very important to evaluate the structural safety and to estimate the life for the worst cases. In this study, the corrosion behaviors of mock-up specimen with box girder were examined by visual inspection.

The correlation between the degradation scores and service life of the coating is derived by tests and inspection for the coated steel member according to each service environment of several facilities. This correlation called to as the deterioration model can be used to determine the performance grade for the durability of coated steel member of facilities under each service environment, for example, atmospheric, fluvial and marine environment.

To ensure the safety of weathering steel structures, it is important to evaluate the time-dependent corrosion behavior. Thus, progress and effect of corrosion damage on weathering steel members should be evaluated, but predicted corrosion depth do not go far enough until now, which is affected by the corrosion environment. In this study, the corrosion resistant of weathering steel was examined to quantifiably investigate and compare the corrosion depth of carbon and weathering steel.

Visual inspection has generally been applied to examine the coating deterioration. However, it was difficult to evaluate an anti-corrosion performance of paint film. In this study, thus, to quantitatively evaluate an anti-corrosion performance of paint film under various corrosion enviornent, change in the impedance paint coating was evauated using EIS (Electrochemical Impedance Spectroscopy).

A steel tubular member has been generally used for the offshore structure. Its stucutral performance can be decreased due to corrosion damage under severe corrosion environment In this study, to examine the compression performance of steel tubular member depending on corrosion thickness, damaged ratio, FE analyses were conducted and compared.

To ensure the safety of weathering steel structures, it is important to evaluate the time-dependent corrosion behavior. Thus, progress and effect of corrosion damage on weathering steel members should be evaluated, but predicted corrosion depth do not go far enough until now, which is affected by the corrosion environment. In this study, the corrosion resistant of weathering steel was examined to quantifiably investigate and compare the corrosion depth of carbon and weathering steel.

Visual inspection has generally been applied to examine the coating deterioration. However, it was difficult to evaluate an anti-corrosion performance of paint film. In this study, thus, to quantitatively evaluate an anti-corrosion performance of paint film under various corrosion enviornent, change in the impedance paint coating was evauated using EIS (Electrochemical Impedance Spectroscopy).