• Journal of the Korea institute for structural maintenance and inspection
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• v.14 no.2
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• pp.153-160
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• 2010

The widespread deterioration of concrete structures has required the development of new and innovative materials and technologies for strengthening and repair. Recently Fiber reinforced polymer(FRP) composites have received widespread attention as materials for the strengthening and repair of the deteriorated concrete structures. This paper presents the results of Fire-performance of RC beams strengthened with FRP-Aluminum composit hollow beams. Test results show that the higher-damaged FRP strengthened RC beams are more vulnerable to the fire and decrease the effect of FRP strenthening.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2003.05a
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• pp.80-87
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• 2003

원자력발전소에서 발생하는 화재사건은 원자로 정지를 유발함과 동시에 안전정지 또는 사고완화 기능을 수행하는 다수의 기기를 동시에 손상시킬 수 있어 원자력발전소의 안전성에 적지 않은 영향을 줄 수 있다. 현재 원자력발전소에서 화재사고의 중요성은 실제 경험뿐만 아니라 국내외 원자력발전소에 대한 화재사건 분석을 통하여 원자력발전소에서 화재사고의 중요성에 대한 인식이 높아지고 있는 상황이며, 각 발전소에서는 설계단계에서부터 보다 강화된 화재방호 기준을 적용하고 있는 실정이다.(중략)

• Journal of the Korea Concrete Institute
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• v.18 no.3 s.93
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• pp.431-438
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• 2006

The determination of the depth of deteriorated concrete is one of the main problems in the structural assessment of concrete structures that have been subjected to a fire. This information is particularly important in order to optimize the future operations of repair/strengthening, or in decision-making concerning a possible demolition. The purpose of this study is to propose evaluation technique of damaged depth of concrete exposed at high temperature. In order to evaluate damaged depth of core picked at member under fire, the 24 specimens have been made with variables of concrete strength(20 MPa, 40 MPa, 60 MPa) and heating exposure condition in 600 and 800 for 2 hours. Color change analysis and water absorption after heating have been measured and split tensile stress test was performed to ka the residual compressive strength against the depth of specimen. The results show that the deeper of the depth from heating face, water absorption ratio is smaller and residual stress ratio is larger and the color of heated face is changed to red color. Using this technique at damage evaluation of fired structure, We evaluate damaged depth of member under fire and determine the reasonable strengthening range.

• Proceedings of the KIEE Conference
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• 2006.05a
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• pp.60-62
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• 2006

전원 코드에서의 전기재해는 외부의 기계적피로에 의해 피복이나 피복 내부의 도체가 손상되어 이루어지는 경우가 많다. 특히, 전기청소기, 모발건조기 등 이동용 전기제품에서 잦은 반복 스트레스로 인해 전원 코드에서 반단선에 의한 전기화재가 발생한다. 본 연구에서는 전원 코드에 반복 스트레스를 받았을 때 전선의 소선이 손상되는 과정을 X-ray를 이용하여 소손 패턴을 분석하였으며, 반단선에 의한 불꽃 발생과정을 초고속 카메라로 촬영하였다. 또한 소손된 전원 코드를 실체 현미경 및 금속현미경을 이용하여 전선피복과 도체에 나타나는 특징을 분석하였다. 이러한 연구를 통하여 전원코드의 반복 피로에 의한 화재발생 메커니즘과 화재원인 분석에 유용한 자료가 될 것으로 기대된다.

• Magazine of the Korea Concrete Institute
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• v.7 no.2
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• pp.117-125
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• 1995

In this study, the damage to a concrete br~dge pier due to flre caused by the fall of an oil truck were investigated by the use of FEM and by tensile tests for reinfortements. And thtse results were analyzed and compared with the measured values. In the FEM calculations, the selected variable was the fire temperature $T_a=500-800^{\circ}C$. The fixed values were the heat transition coefficient ${\alpha}=2000W/m^2{\cdot}K$. the initial temperature of concrete $T_0=5{\circ}C$ and the fire duration t=30 minutes. As the results obtained from numerical calculations, the property darrlage zone ap,)eared to be 1.5-4.1cm and the structure damage zone appeared to be 8.7- 10.1cm from the concrete surface. And this results give values very similar to those measured, nanlelv 2-4cm and 8~10cm respectively. The results frorn tensile tests give no serious loss of the tensile strength.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.41 no.2
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• pp.93-100
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• 2021

The objective of this research is to evaluate of fire damage for steel-concrete composite bridge superstructure and PSC bridge superstructure under highway bridge exposed to fire loading. To enhance the accuracy and efficiency of the numerical analysis, the proposed heat flow fire analysis method is implemented in ANSYS. The proposed heat flow analysis method is applied to fire damage analysis and performance evaluation for Buchen and Yangsan highway bridge. The result of analysis, temperature of concrete slab and lower flange of steel-concrete composite bridge superstructure are exceed the critical temperature. Also, temperature of slab, lower and upper flange, web of PSC bridge superstructure are exceed the critical temperature. However, the major component, tendon, did not exceed the critical temperature.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.9
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• pp.472-482
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• 2016

The purpose of this study was to determine if a geriatric injury would have a statistically significant relationship with the spatial safety within a specific region. To achieve the objectives of this study, an independent sample t-test and One-way ANOVA were performed to verify difference in mean value of regional safety grade, depending on the injury intentionality, injury location, activities at the time of injury, and injury mechanism, in 6,572 geriatric injury patients by combining the National Hospital Discharge Patients Injury Survey data and regional safety index data. The results of statistical validation suggested that there was no difference in the mean value of regional safety grade by sub-group with respect to the injury intentionality. However, a statistically significant difference was observed in terms of the mean value of regional safety grade in each sub-group with regard to the injury location, activities at the time of injury, and injury mechanism in connection with some areas of the regional safety index. Based on the results of such analysis, we derived and presented 3 implications related to policies and practice for the prevention of geriatric injury and a reduction of its occurrence rate in light of spatial safety after a discussion of the results through a comparison with previous studies that examined individual areas.

• Fire Science and Engineering
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• v.24 no.3
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• pp.145-151
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• 2010

The fire in tunnel, when failed to extinguish at early stage, tends to easily develop to high temperature and spread to entire area of the tunnel because of considerable level of fire load and smoke control facility within the tunnel, resulting in severe damage to the people and tunnel structure. This study was intended to carry out the fire test with MHC fire curve, a scenario, which has the most rapid fire rise, on assumption of load ratio of 1, 20, 40, 60 and 70%, so as to identify the thermal characteristics of the concrete against spalling and the range of fire damage. The specimen was small scale sample as defined by EFNARC and the mixing ratio was based on 24 MPa, which is considered to be the normal strength. As a result of test, 16mm spalling was occurred on the lining under the non-load condition, while no spalling was occurred with 20% and 40% of load ratio. In case of 60% of load ratio, 24 mm of spalling was occurred and it failed in 10 minutes after heating in case of 70% load condition.

• Journal of the Korea Concrete Institute
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• v.26 no.4
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• pp.429-440
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• 2014

Since the World Trade Center and Pentagon attacks in 2001, terror, military attack, or man-made disaster caused impact, explosion, and fire accident have frequently occured on civil infrastructures. However, structural behavior researches on major Prestressed Concrete (PSC) infrastructures such as bridges, tunnels, Prestressed Concrete Containment Vessel (PCCVs), and LNG tanks under extreme loading are significantly lacking. Especially, researches on possible secondary fire scenarios after terror, bombing, collision of vehicles and vessels on concrete structures have not been performed domestically where most of the past researches related to extreme loadings on structures focused on an independent isolated extreme loading scenario. Due to the outcry of public concerns and anxiety of potential terrorist attacks on major infrastructures and structures, a study is urgently needed at this time. Therefore, in this study, the bi-directional prestressed concrete $1400{\times}1000{\times}300mm$ panels applied with 430 kN prestressing force using unbonded prestressing thread bars were experimentally evaluated under impact, fire, and impact-fire combined loadings. Due to test site restrictions, impact tests were performed with 14 kN impactor with drop heights of 10m and 3.5 m to evaluate impact resistance capacity. Also, fire and impact-fire combined loading were tested using RABT fire loading curve. The measured residual strength capacities of PSC and RC specimens applied with impact, fire, impact-fire combined loadings were compared with the residual strength capacity of undamaged PSC and RC specimens for evaluation. The study results can be used as basic research data for related research areas such as protective design and numerical simulation under extreme loading scenarios.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.11a
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• pp.191-192
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• 2013

원전 화재 PSA에서 화재 초기사건발생빈도는 전체 노심손상빈도에 직접 비례하여 영향을 주기 때문에 중요한 요소이다. 미국 NRC는 EPRI와의 공동연구를 통하여 원전 화재 PSA의 신규 방법론(NUREG/CR-6850)을 개발하였고, 미국 원전사업자들은 신규 방법론을 적용하여 화재 PSA를 수행하고 있다. 최근 EPRI는 원전 화재 초기사건 발생빈도 추정시 NUREG/CR-6850에서 사용된 화재심각도 분류방법을 개정한 지침서를 발간하였다. 본 논문에서는 신규 분류기준에 대해서 살펴보고, 국내 원전에서 경험한 화재사건에 대해서 신규 분류 기준을 적용하여 고찰하였다.