• Title/Summary/Keyword: Fire size

Search Result 642, Processing Time 0.031 seconds

Fire resistance of high strength fiber reinforced concrete filled box columns

  • Tang, Chao-Wei
    • Steel and Composite Structures
    • /
    • v.23 no.5
    • /
    • pp.611-621
    • /
    • 2017
  • This paper presents an investigation on the fire resistance of high strength fiber reinforced concrete filled box columns (CFBCs) under combined temperature and loading. Two groups of full-size specimens were fabricated. The control group was a steel box filled with high-strength concrete (HSC), while the experimental group consisted of a steel box filled with high strength fiber concrete (HFC) and two steel boxes filled with fiber reinforced concrete. Prior to fire test, a constant compressive load (i.e., load level for fire design) was applied to the column specimens. Thermal load was then applied on the column specimens in form of ISO 834 standard fire curve in a large-scale laboratory furnace until the set experiment termination condition was reached. The test results show that filling fiber concrete can improve the fire resistance of CFBC. Moreover, the configuration of longitudinal reinforcements and transverse stirrups can significantly improve the fire resistance of CFBCs.

Assessment of Grid Sensitivity in the FDS Field Model to Simulate the Flame Propagation of an Electric Cable Fire (케이블 화재의 화염전파 해석을 위한 FDS 모델의 격자민감도 평가)

  • Kim, Sung-Chan;Lee, Seong-Hyuk
    • Journal of the Korean Society of Safety
    • /
    • v.23 no.4
    • /
    • pp.30-35
    • /
    • 2008
  • The present study has been conducted to examine the effect of grid resolution on the predicted results for electric cable fire using pyrolysis model in FDS(Fire Dynamics Simulator, version 5). The grid independent test for different grid resolutions has been performed for a PE coating cable and the grid resolution is defined by the non-dimensional characteristic length of fire and mean grid size. The calculated maximum heat release rate and mean flame spread rate were almost constant for higher grid resolution of 20${\sim}$25 and the computing time for the grid resolution takes approximately 20hours to solve flame propagation with pyrolysis model. The geometrical simplification of a electric cable dose not greatly affect on the maximum heat release rate and flame spread rate and the rectangular approximation of cable shape gives acceptable result comparing with the round cable with stepwise grid.

Preparation of High-purity Porous Alumina Carrier for Gas Sensor (가스센서용 고순도 다공질 알루미나 담체의 제조)

  • 이창우;현성호;함영민
    • Fire Science and Engineering
    • /
    • v.11 no.3
    • /
    • pp.15-23
    • /
    • 1997
  • In this study, the alumina for gas sensor was prepared by anodic oxidation. It was stable thermally and chemically, and pore diameter and pore distribution was uniform. And the shape of pore was cylinderical. The aluminum plate was carried out by the thermal oxidation, chemical polishing and electropolishing pretreatment. The pore diameter, pore size distribution, pore density and thickness of alumina was observed with the change of reaction temperature, electrolyte concentration and current density. As a results, It was able to use for carrier because alumina which was prepared by anodic oxidationhas uniform pore size distribution.

  • PDF

A Study on the Effective Method of Fire Extinguisher Maintenance In the Underground Parking Lot of the Apartment (아파트 지하주차장 소화기의 유지관리 효율화 방안에 관한 연구)

  • Lee, Young-Sam
    • Journal of the Korea Safety Management & Science
    • /
    • v.18 no.3
    • /
    • pp.1-8
    • /
    • 2016
  • The definition of an apartment is a building more than 5 stories high and which is the standard law. Currently, the number of apartments is increasing much faster than detached houses. Owning an apartment is a normal trend these days. However, the increasing number of apartments has been increasing the number of apartment fires which also has been making social problems. Therefore, this study was conducted for the fire extinguisher among other fire facilities because it is important for initial fire suppression. The research subject is on the fire extinguisher that is in the underground parking lot of 40 apartment complexes which are more than 10 stories. Survey and analysis were conducted for 80 fire extinguishers. There are two fire extinguishers for each apartment. The result of this study is that all installed fire extinguishers are ABC dry chemical type, 92% of them is 3.3kg and that meet the legal height(less than 1.5m). However, the condition such as appearance, inspection, manufactured year, appearance of signs, material of signs, size of signs, etc. was insufficiency. So improvement of law and system that are fire facility construction, maintenance implementation and additional designation of type approval about sign will be needed in my opinion.

A Study on the Damaged Pattern of Dryvit by External Flame (외부화염에 의한 드라이비트의 소손패턴 연구)

  • Park, Young Ju;Hong, Yi Pyo;Lee, Hae Pyeong
    • Journal of the Korean Society of Safety
    • /
    • v.30 no.6
    • /
    • pp.40-47
    • /
    • 2015
  • In this study, temperature characteristics and fire damage form were analyzed to investigate flame spreading form and fire probability from ignition sources subject to drivit component materials which is finishing material in architecture. Ignition sources were limited to a gas torch and exterior panel board fire, and the size of the sample was manufacture in 30 cm length ${\times}$ 50 cm height ${\times}$ 5cm thickness size. Marble (inner wall) + 3 mm drivit (outer wall), marble (inner wall) + 4 mm plaster stone (outer wall), sandwich panel + 3 mm driver bit (outer wall), sandwich panel + 3 mm driver bit + insulation (outer wall), and gypsum board (inner wall) + 3 mm drivit (outer wall) were prepared for the sample. As result of the research for temperature characteristics, large temperature difference by each material was shown in $218^{\circ}C{\sim}995^{\circ}C$ at 30 seconds and $501^{\circ}C{\sim}1078^{\circ}C$ at 300 seconds. Especially when the inner wall was a plaster board, lowest temperature of $501^{\circ}C$ was shown at 300 seconds and marble inner wall showed the following lowest temperature of $900^{\circ}C$. Temperature rising over $1000^{\circ}C$ was shown in other materials. Regarding fire damage form, drivit or gypsum board outer wall parts exposed to fire showed combustion and carbonization to show calcination(breaking phenomenon) and influence of heat exposure was higher as calcination became more severe.

Research and development of a three-stage door binder to improve the fire resistance of fire doors (방화문의 내화성능 향상을 위한 3단 문 결속기 연구개발)

  • Lim, Bo-Hyeok;Lee, Joo-Won;Cho, Dong-Hwan;Lee, Hae-Yeol
    • Proceedings of the Korean Institute of Building Construction Conference
    • /
    • 2023.11a
    • /
    • pp.157-158
    • /
    • 2023
  • Doors that are opened and closed when entering or exiting a general building are connected to the door frame and open and close. They are equipped with door locking devices of various structures, and are either locked to the door frame for the closing operation or released from the door frame for the opening and closing operation. Here, a single-stage door binding device having a door latch that is independently disposed at the center of one axis of the door is commonly used. On the other hand, if the size of the door is over a certain size or if the door is medium to large, the opening and closing operation may not be performed smoothly with only a single stage binder, or the closing state may not be achieved stably during the closing operation. In particular, in the case of the single-stage binding device provided in medium to large fire doors, the door is fixed to the door frame unstable, causing fatal errors in the fire prevention function of the fire door. Accordingly, in order to fundamentally solve these problems, we researched and developed a three-stage door binding machine that combines a top and bottom fastening structure with a single-stage fastening structure. This 3-stage door binder not only has the fire resistance performance of a fire door, but also has a T-shaped terminal in its fastening method, so if you eliminate the upper and lower fastening, it is a 1-stage binder like a regular product, but if you remove the door latch of the 1st-stage binder, it functions as an upper and lower 2-stage binder and forms a single mold. We researched and developed a three-stage door binder that can manufacture and produce three products at the same time, satisfying both product performance and price.

  • PDF

Sensitivity Analysis for Fire Risk Conditions of Fire Area at Nuclear Power Plant with Performance-based Fire Model (FDS) (성능기반 화재모델(FDS)을 이용한 원전 방화지역 화재위험 분석조건에 대한 민감도 해석)

  • Jee, Moon-Hak;Lee, Byung-Kon;Jeoung, Rae-Hyuck
    • Fire Science and Engineering
    • /
    • v.21 no.2 s.66
    • /
    • pp.98-104
    • /
    • 2007
  • This study is related with the fire risk assessment for fire area at nuclear power plant by use of FDS (Fire Dynamics Simulator) that is a computational fluid dynamics (CFD) model of fire-driven fluid flow. The major purpose of this research is to analyze the sensitivity of the fire modeling when the heat release rate that is an important input variable is changed as well as when the grid size that is a critical factor of the fire model is modified. The result is presented at the conclusion with some comments for CFD model application.

Estimating Unsteady Soil Loss due to Rainfall Impact according to Rim Fire at California

  • Choi, Hyun;Kim, Gihong
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
    • /
    • v.35 no.4
    • /
    • pp.269-280
    • /
    • 2017
  • Recently, in the United States, there has been short-term intensive rainfall due to El Ni?o and Rania. The Rim Fire was a wildland fire that was started in a remote canyon in Stanislaus National Forest in California. This portion of the central Sierra Nevada spans Tuolumne and Mariposa counties. This study is about estimating unsteady soil loss due to rainfall impact according to Rim Fire at California. It implies that caution needs to be taken in selecting the grid size for estimating soil loss using numerical modeling approach. Soil loss increased in all duration times before Rim fire. But it increased until 7 days and reduced or kept stable after that. Based on the 2014 average rainfall 1388 mm/yr, soil loss was estimated to be 247,518 ton/ha/yr before Rim Fire, and 9,389,937 ton/ha/yr after that.

Fire Resistance Performance of FRP Rebar Reinforced Concrete Columns

  • Wang, Hui;Zha, Xiaoxiong;Ye, Jianqiao
    • International Journal of Concrete Structures and Materials
    • /
    • v.3 no.2
    • /
    • pp.111-117
    • /
    • 2009
  • Concrete columns reinforced with Fibre Reinforced Polymer (FRP) rebar have been increasingly used in civil engineering applications, while the research on fire resistance of such structural members is still very limited. In this paper, attempts are made to predict temperature distribution and mechanical performance of FRP rebar reinforced concrete columns in fire. The effect of concrete cover and section size on fire resistance time is studied by the finite element method. Based on a parametric study, a simple empirical formula to predict fire resistance time is proposed for possible adoption in fire resistance design.

A Study on Adhesion Test Methods for Fire Hose (소방호스 밀착강도시험방법에 관한 연구)

  • 김준배;백창선;김학진
    • Fire Science and Engineering
    • /
    • v.15 no.1
    • /
    • pp.66-74
    • /
    • 2001
  • In order to improve the adhesion test methods for fire hose, 7 kinds of standards (KOFEIS, UL, FM, NFPA, BS, Chinese standard, JIS, JFEII standard) in 5 countries (Korea, USA, UK, China, Japan) were compared and adhesion tests were conducted by using the samples choosed randomly from the product produced in Korea. It was concluded that the sample size, the rate of seperation of a strip of the lining from the janet and standard judgment should be more differed and divided in accordance with the fire hose number in adhesion test to get the high Quality of fire hose.

  • PDF