• Title/Summary/Keyword: structural fire

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Predicting the bond between concrete and reinforcing steel at elevated temperatures

  • Aslani, Farhad;Samali, Bijan
    • Structural Engineering and Mechanics
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    • v.48 no.5
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    • pp.643-660
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    • 2013
  • Reinforced concrete structures are vulnerable to high temperature conditions such as those during a fire. At elevated temperatures, the mechanical properties of concrete and reinforcing steel as well as the bond between steel rebar and concrete may significantly deteriorate. The changes in the bonding behavior may influence the flexibility or the moment capacity of the reinforced concrete structures. The bond strength degradation is required for structural design of fire safety and structural repair after fire. However, the investigation of bonding between rebar and concrete at elevated temperatures is quite difficult in practice. In this study, bond constitutive relationships are developed for normal and high-strength concrete (NSC and HSC) subjected to fire, with the intention of providing efficient modeling and to specify the fire-performance criteria for concrete structures exposed to fire. They are developed for the following purposes at high temperatures: normal and high compressive strength with different type of aggregates, bond strength with different types of embedment length and cooling regimes, bond strength versus to compressive strength with different types of embedment length, and bond stress-slip curve. The proposed relationships at elevated temperature are compared with experimental results.

Slab panel vertical support and tensile membrane action in fire

  • Abu, Anthony K.;Burgess, Ian W.;Plank, Roger J.
    • Steel and Composite Structures
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    • v.8 no.3
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    • pp.217-230
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    • 2008
  • The increasing use of performance-based approaches in structural fire engineering design of multi-storey composite buildings has prompted the development of various tools to help quantify the influence of tensile membrane action in composite slabs at elevated temperatures. One simplified method which has emerged is the Bailey-BRE membrane action method. This method predicts slab capacities in fire by analysing rectangular slab panels supported on edges which resist vertical deflection. The task of providing the necessary vertical support, in practice, requires protecting a panel's perimeter beams to achieve temperatures of no more than $620^{\circ}C$ at the required fire resistance time. Hence, the integrity of this support becomes critical as the slab and the attached beams deflect, and large deflections of the perimeter beams may lead to a catastrophic failure of the structure. This paper presents a finite element investigation into the effects of vertical support along slab panel boundaries on the slab behaviour in fire. It examines the development of the membrane mechanism for various degrees of edge-beam protection, and makes comparisons with predictions of the membrane action design method and various acceptance criteria.

Dynamic Response of Drill Floor to Fire Subsequent to Blowout

  • Kim, Teak-Keon;Kim, Seul-Kee;Lee, Jae-Myung
    • Journal of Ocean Engineering and Technology
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    • v.34 no.2
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    • pp.110-119
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    • 2020
  • Explosions and fires on offshore drilling units and process plants, which cause loss of life and environmental damage, have been studied extensively. However, research on drilling units increased only after the 2010 Deepwater Horizon accident in the Gulf of Mexico. A major reason for explosions and fires on a drilling unit is blowout, which is caused by a failure to control the high temperatures and pressures upstream of the offshore underwater well. The area susceptible to explosion and fire due to blowout is the drill floor, which supports the main drilling system. Structural instability and collapse of the drill floor can threaten the structural integrity of the entire unit. This study simulates the behavior of fire subsequent to blowout and assesses the thermal load. A heat transfer structure analysis of the drill floor was carried out using the assessed thermal load, and the risk was noted. In order to maintain the structural integrity of the drill floor, passive fire protection of certain areas was recommended.

A Evaluation on Flexural Behavior for Hollow Core Slab of Fire Resistance section for Residence Building (주거용 내화단면 중공슬래브의 휨거동 평가)

  • Boo, Yoon-Seob;Bae, Kyu-Woong;Shin, Sang-Min
    • Journal of Korean Association for Spatial Structures
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    • v.23 no.2
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    • pp.61-68
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    • 2023
  • A two-hour fire-resistance PC hollow slab for residential use was developed to secure structural and fire-resistance performance and to be applied to the general building and apartment housing markets. Compared to the existing hollow slab, in order to secure the same or better structural performance and economic feasibility by reducing the quantity, it was attempted to secure the fire resistance performance by reducing the concrete filling rate in the cross section and adjusting the thickness of the upper and lower flanges by optimizing the hollow shape in the cross section of the slab. For structural performance evaluation, experiments were performed on PC hollow slabs by varying the member thickness and the presence or absence of overlaid concrete, and all of the experimental results showed that the design strength was sufficiently exhibited and that stability during construction was possible. The developed synthetic PC hollow slab has secured fire resistance and residential performance so that it can be applied to all buildings, and it is intended to be immediately applied to the field.

Explosive Spalling of Structural Lightweight Aggregate Concrete (구조용 경량골재 콘크리트의 폭렬특성)

  • Song, Hun;Lee, Jong-Chan;Lee, Sea-Hyun;Kim, Woo-Jae
    • Proceedings of the Korea Concrete Institute Conference
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    • 2006.05b
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    • pp.477-480
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    • 2006
  • Normally, with all ensuring the fire resistance structure as a method of setting the required cover thickness to fire, the RC is significantly affected from the standpoint of its structural stability that the compressive strength and elastic modulus is reduced by fire. Especially, high strength concrete and lightweight aggregate concrete is occurred serious fire performance deterioration by explosive spalling. Thus, this study is concerned with explosive spalling of lightweight concrete using structural lightweight aggregate. From the experimental test result, lightweight aggregate concrete is happened explosive spalling. The decrease of cross section caused by explosive spalling made sharp increasing gradient of inner temperature.

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Structural Design Guide Line of Composite Beam (내화피복이 생략된 합성보의 구조설계지침 제정을 위한 고찰)

  • Hong, Won-Kee;Kim, Jin-Min;Lee, Kyoung-Hun;Park, Seon-Chee;Kim, Jeom-Han
    • KIEAE Journal
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    • v.8 no.1
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    • pp.93-98
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    • 2008
  • As high rise buildings and large span spatial structures are constructed, new composite members and construction techniques are continuously developed. Wide flange steel beam can be easily constructed but the fire proofing protection is necessary and the cost is high. Nowadays environmental pollution of structures is becoming a big issue. The material of fire proofing protection is not allowed to use for structural members in several countries because it cab be a cause of environment pollution. Composite beam is a new hybrid beam system which is not needed a fire proofing protection process. Composite beam has better construction capacity than that of RC system and has more economic advantages than that of wide flange steel beam. In this paper, structural design guide lines of composite beam were provided to apply design and construction.

Characteristics of Temperature Distribution of Axially Loaded CFT Column with Fire Protection (축하중을 받는 내화피복 CFT기둥의 온도분포 특성)

  • Kim, Hae-Soo;Yoon, Sung-Kee
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.4
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    • pp.78-85
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    • 2010
  • When the fire occur, concrete filled steel tube(CFT) columns expected to form a much distinction in a fire resistance performance according to a kind of fire protection because the steel surface is directly exposed to high temperature. In this study, an experiment by three factors which were kind of fire protection, thickness of protection and time was performed to get the characteristics of temperature distribution types of CFT column with fire protection. As the result of this study, on a basis of heating temperature, spray protection was the most superior in a fire resistance performance, fireproof paint was next, and without fire protection was most inferior. In a heating time-location relationship, the temperature increased slowly on the surface of the concrete, but the temperature increased sharply on the surface of the steel.

An Evaluation of Fire Resistance and Mock-up Test of the Alumino-silicate Fire Resistant Board (알루미노 실리케이트계 내화보드의 내화성능 및 현장적용성 평가)

  • Kim, Doo-Ho;Park, Dong-Cheol;Kim, Woo-Jae;Lee, Sea-Hyun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2010.05b
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    • pp.43-47
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    • 2010
  • The use of high-strength concrete has increased for its excellent structural stability as buildings become higher and bigger than ever before in Korea and overseas recently. The functional requirement of building materials has also been bolstered so for the high -performance, high-quality construction materials to be used more extensively. However, the internal structure of the high-strength concrete is very dense so spalling can be caused during fire. The spalling in turn can cause critical structural damages followed by the fatal consequences, demolition of the building. Therefore, ensuring fire safety for high-rise buildings is assumed to be urgent. Alumino-silicate fire resistant board producing technology has been developed in situations that new materials with excellent fire resistance and easy installation has been sought. The alumino-silicate fire resistant board turned out to exhibit not only fire resistance and excellent physical and dynamical characteristics but also excellent onsite applicability and easy process and transportation after completing Mock-up test. Its excellence as a high-performance building materials was proven.

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BIM and Fire Safety Engineering - Overview of State of The Art

  • Davidson, Anne;Gales, John
    • International Journal of High-Rise Buildings
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    • v.10 no.4
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    • pp.251-263
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    • 2021
  • Fire safety engineering is a critical specialization to include in the design of a tall building yet is often excluded from the Building Information Model (BIM) and integrated design process. The design of fire safety systems is interdependent with building/structural geometry, HVAC, mechanical, and electrical systems. A BIM is a 3D visual representation that stores data on these kinds of systems. The compatibility between BIM and fire safety design seems obvious yet has received a dearth of attention in structural (fire) engineering literature. The authors herein have reviewed over 40 recent papers on utilizing BIM for fire safety engineering, focusing on contemporary literature to obtain a more up-to-date review of the state-of-the-art. The resulting trends, technologies, research gaps, and methodologies are presented in this paper. Adoption of BIM in fire safety engineering is slow and behind other disciplines which may be improved if research involved more industry partners. For BIM technology to reach its potential, industry manufacturers need to provide high LOD fire BIM objects, fire engineers and researchers need to collaborate on future advancements, and building owners/management need to be educated on how to use the benefits provided.