Light-Weight Frame Wall Assemblies: Parameters for Consideration in Fire Resistance Performance-Based Design

With the advent of performance-based codes and fire safety design options, it is essential to determine parameters that affect the fire-resistance performance of assemblies. This paper presents the results of 17 full-scale fire-resistance tests conducted as part of a major industry-government research program investigating parameters that affect the fire-resistance performance of light-weight frame wall assemblies. These include the effects of insulation type, insulation width between studs, resilient channel location, gypsum board thickness, number of gypsum board layers, glass fiber in the gypsum board core, gypsum board mass per unit area, and stud type for light-weight frame wall assemblies finished with gypsum board. The effects of these parameters on the fire resistance are discussed.     

Fire Resistance of Wood Joist Floor Assemblies

This paper discusses the factors that affect the fire resistance performance of lightweight wood frame unrestrained floor assemblies protected with Type X gypsum board ceiling finishes. Twenty-two fire resistance experiments were conducted on full-scale load-bearing wood joist floor assemblies using the ULC standard fire exposure time–temperature curve that is similar to ASTM E119 standard. Parameters investigated in this study include the effects of gypsum board screws spacing from board edges, insulation installation, insulation type, joist spacing for assemblies with gypsum board attached to resilient channels, joist depth, resilient channel installation, resilient channel spacing, sub-floor topping, number of sub-floor layers, and load magnitude. The impact of these parameters on the fire resistance of wood joist frame floor assemblies is discussed. The fire resistance of wood frame floors appears essentially to be governed by the gypsum board screw spacing from the board edges and the type of insulation in assemblies with one layer of gypsum board and by the resilient channel spacing and the gypsum board screw spacing from the board edges in assemblies with two layers of gypsum board. The effects of other parameters in assemblies with two layers of gypsum board such as the joist spacing where the gypsum boards are attached to resilient channels, installation of resilient channels, insulation installation, insulation type, adding gyp-crete topping above the sub-floor and number of sub-floor layers on fire resistance are relatively insignificant.     

Fire Resistance of Steel C-Joist Floor Assemblies

This paper discusses the factors that affect the fire resistance performance of lightweight steel-framed (LSF) unrestrained floor assemblies protected with Type X gypsum board ceiling finishes. Sixteen fire resistance experiments were conducted on full-scale load-bearing steel C-joist floor assemblies using the ULC standard fire exposure time–temperature curve that is similar to ASTM E119 standard. Parameters investigated in this study include the effects of insulation installation, insulation type, joist spacing, resilient channel installation, resilient channel spacing, type of sub-floor layer and number of sub-floor layers versus number of gypsum board layers. The impact of these parameters on the fire resistance of steel C-joist frame floor assemblies is discussed. The fire resistance of LSF floors appears to be essentially governed by the number of gypsum board layers, spacing of the joists or resilient channels where the gypsum boards are attached, sub-floor type and insulation type. Other parameters are of secondary importance.     

Fire Resistance of Loadbearing Steel-Stud Wall Protected with Gypsum Board: A Review

With the increased use of cold-formed lightweight steel framing (LSF), there is growing demand for the proper assessment of its performance in building fires. In partnership with the North American steel industry, the National Research Council of Canada (NRC) is conducting an experimental and analytical study on the fire resistance of loadbearing cold-formed steel-framed wall and floor assemblies. As part of this collaboration, this literature survey summarizes the information available on the topics related to the fire resistance of loadbearing cold-formed steel-stud walls clad with gypsum board. The current practice of establishing their fire-resistance rating, based on full-scale furnace tests, is assessed. Previous experimental and analytical studies on the subject and on the thermal and mechanical properties of the constituent materials—steel, gypsum board, and insulation—at elevated temperatures are also discussed. Future research needs are identified in the context of recent performance-based fire safety engineering concepts.     

火灾下腹板开孔轻钢龙骨墙体温度场数值模拟分析

采用有限元分析软件ABAQUS建立了腹板开孔轻钢龙骨围护墙体温度场分析模型,阐述了模型中的若干关键问题,如受火面与背火面边界条件,石膏板、岩棉和钢材的热工性能参数及材料间的接触条件等,并将模拟结果与相关试验结果进行对比。在此基础上,分析了相关参数对腹板开孔轻钢龙骨墙体背火面的最高温度和平均温度的影响规律。结果表明:该模型可有效模拟该类墙体在火灾下的温度分布;龙骨截面高度与石膏板层数及布置方式均可在较大程度上影响墙体背火面的最高温度与平均温度;腹板开孔排数只对背火面最高温度影响较大,对平均温度则影响不大。     

Experimental study on the performance of a load-bearing steel stud gypsum board wall assembly exposed to a real fire

The National Institute of Standards and Technology (NIST) and the Center for Better Living (CBL) have formed an international collaboration to assess the performance and failure mechanisms of gypsum wall assemblies under real fires/furnace conditions. In an effort to compile an experimental database necessary to validate models that could be used to predict their performance and ultimate failure under various design fires, a full scale test was conducted in the Large Fire Laboratory (LFL) at NIST. This paper provides a valuable experimental data set on the performance of a full scale loaded gypsum steel stud assembly exposed to an intense full scale compartment fire.     

Behavior of steel-sheathed shear walls subjected to seismic and fire loads

A series of tests was conducted on six 2.7 m×3.7 m shear wall specimens consisting of cold-formed steel framing sheathed on one side with sheet steel adhered to gypsum board and on the opposite side with plain gypsum board. The specimens were subjected to various sequences of simulated seismic shear deformation and fire exposure to study the influence of multi-hazard interactions on the lateral load resistance of the walls. The test program was designed to complement a parallel effort at the University of California, San Diego to investigate a six-story building subjected to earthquakes and fires. The test results reported here indicate that the fire exposure caused a shift in the failure mode of the walls from local buckling of the sheet steel in cases without fire exposure, to global buckling of the sheet steel with an accompanying 35% reduction in lateral load capacity after the wall had been exposed to fire. This behavior appears to be predictable, which is encouraging from the standpoint of residual lateral load capacity under these severe multi-hazard actions.     

EPS钢丝网架板现浇混凝土外墙外保温施工技术

基于节能标准要求的提高,EPS钢丝网架板现浇混凝土外墙外保温技术被广泛应用于当今的工业与民用建筑之中,根据混凝土外墙外保温的施工难点,提出相应的解决措施,并阐述了保温板安装、细部加强、模板安装、混凝土浇筑等施工工艺,以供参考。     

新型轻钢复合墙体承重抗火试验及其墙柱热翼缘温升简化计算研究

提出以蒸压加气混凝土(ALC)板与玻特(CS)板作为覆板组合、以钢蒙皮和钢带作为墙板拼缝保护措施的新型轻钢复合墙体构造,开展了ALC板-CS板覆面的新型构造轻钢复合墙体足尺模型承重抗火试验。将轻钢复合墙体受火侧由不同覆板组合而成的防火构造简化为一层均质防护层,提出均质防护层的等效热物理参数(包括厚度、比热容、密度和导热系数)简化计算方法。根据能量守恒原理以及有限差分方法,提出ALC板-CS板覆面轻钢复合墙体的墙柱热翼缘受火温升简化增量表达式。结果表明:ALC板-CS板覆面轻钢复合墙体在0.27荷载比率条件下发生高温承载力失效的耐火极限达到197 min,表现出优异的耐火性能; 提出的温升简化增量表达式预测结果与有限元模拟结果吻合良好,可以用于确定轻钢复合墙体的耐火极限。     

高温下墙板约束对轴心受压钢柱承载力的影响

外挂墙板的钢柱在火灾下的受力特性与单纯的钢柱有较大差别。通过对火灾下不同荷载比且具有不同连接点的钢柱承载力特性的计算研究,了解带有墙板钢柱在火灾下的特性,为建立带有墙板钢柱的抗火设计方法提供依据。     

Full-scale fire experiments on load-bearing cold-formed steel walls lined with different panels

Cold-formed steel (CFS) wall systems were increasingly used as primary load-bearing structural components in residential and industrial buildings. Previous studies were mainly to investigate the fire performance of non-load bearing CFS wall systems lined with gypsum plasterboards. In order to improve the fire performance of load-bearing CFS wall systems more efficiently, this paper presented a detailed experimental investigation on five full-scale CFS walls lined with double layers of three different fire resistant panels on both sides, including fire-resistant gypsum plasterboard, bolivian magnesium board and calcium silicate board. The results showed a noticeable disadvantage of the calcium silicate board due to explosive spalling at high temperatures, and this might cause severe safety issues in an actual fire situation. For CFS walls lined with gypsum plasterboard as the face layer and bolivian magnesium board as the base layer on both sides, different load ratios may result in different failure modes, and the fire resistance time would be more than 90 min when the load ratio was less than 0.65. It was also demonstrated that the fire performance of bolivian magnesium board was superior to that of the fire resistant gypsum plasterboard, therefore the former may be recommended to be used in CFS structures to replace gypsum plasterboards as the base layer.     

Influence of plastic electrical outlet boxes on sound insulation of gypsum board walls

In this paper, the influence on sound insulation of plastic electrical outlet boxes installed on double leaf steel stud gypsum board walls containing cavity absorption was examined experimentally. It was shown that the effect on sound insulation was negligible. It was also shown that the size of the elctrical boxes had not effect on sound insulation.     

彩钢砖的应用研究

介绍了彩钢砖是以彩钢板及挤塑保温背板复合而成的外墙复合轻质饰面砖,具有防脱落、不伤人、节能、安装方便等特点,就其生产、主要性能指标和技术优势、安装方法等角度展开分析与研究,从性能、效果、安全、便捷等方面对彩钢砖的特点和应用进行分析,从而达到彩钢砖的推广与应用。     

发泡陶瓷保温板外保温系统建筑应用与质量控制

外墙外保温系统的防火性能、耐久性能已备受业内重视。发泡陶瓷保温板是一种新型的防火、保温材料,用于外墙外保温系统可大大提高系统的防火、耐久性能。对该保温材料及其外保温系统、防火隔离带构造进行了研究和试点应用,结果表明该技术防火性能佳、与建筑同寿命、施工便捷、质量通病少,具有广阔的应用前景。详述了其施工和质量控制要点。     

A model for predicting heat transfer through noninsulated unloaded steel-stud gypsum board wall assemblies exposed to fire

With the advent of performance-based codes and performance-based fire safety design options, validated fire-resistance models have become essential. In this paper, a one-dimensional heat transfer model for steel-stud, noninsulated, unloaded gypsum board protected wall assemblies is presented. Also presented are a comparison between temperature predictions and measured temperatures at different locations in gypsum board wall assemblies as well as a comparison between the predicted and measured fire-resistance ratings. The model, which predicts slightly conservative fire-resistance ratings compared to the experimental measurements, is appropriate for most fire safety engineering applications. Considerations for further model development are identified.     

Shear capacity of cold-formed light-gauge steel framed shear-wall panels with fiber cement board sheathing

Being light in weight, cold-formed steel shear wall panels (SWPs) made with light gauge steel are extensively used in residential and office buildings (low to mid-rise), particularly in structures under seismic loadings. Many design practices involve the use of fiber cement board (FCB) as sheathing material both for hollow and infilled walls. FCB is a preferred choice as cladding material due to many advantages it provides such as water resistance, lower cost, withstand temperature variation, resistance to humidity and termite attack, better acoustic insulation, and superior fire resistance properties. In the absence of design guidelines, based on cold-formed light gauge steel shear walls with FCB sheathing, the designers resolve to use the guideline available for gypsum wall board (GWB) and fiberboard (FB) available in American Iron and Steel Institute Lateral Design. As a pioneer study, an experimental program was designed to investigate the behavior of cold-formed light gauge steel shear walls, both hollow and infilled with expanded polystyrene (EPS) foam concrete, with FCB sheathing on both sides under monotonic loading. The tests were performed according to ASTM E564 standard. Results show that the strength of shear walls with FCB sheathing is much higher than GWB and FB sheathing, suggesting that substitute design practices are highly conservative. Test results can help designers choose desired lateral stiffness and load carrying capacity of light gauge steel SWPs more efficiently, by selecting appropriate framing, infill, and sheathing material.     

钢结构围护-防火一体化材料耐火性能试验研究

根据钢结构防火保护材料的相关技术要求,通过对常见的钢结构围护材料进行评价,筛选了包括水泥基材料中的无机轻集料砂浆、胶粉聚苯颗粒、蒸压轻质加气混凝土(autoclaved lightweight concrete,ALC),保温浆料中的石膏基保温浆料、微孔硅酸钙浆料,以及保温板材中的发泡陶瓷保温板和岩棉板在内的3类可以兼...     

岩棉保温装饰一体板在钢边框复合轻质板中的应用研究

探讨一种适用于钢结构装配式住宅的外墙外保温体系的组成、岩棉保温装饰一体板与钢边框复合轻质板的连接方式、外墙外保温体系的系统试验等。该外墙外保温体系具有保温效果好、防火性能优异、体系连接安全、施工效率高等优点,具有广阔的应用前景。     

Fire tests of Magnesium Oxide board lined light gauge steel frame wall systems

Recently, Magnesium Oxide (MgO) board has been widely used in LSF wall systems because of its improved acoustic properties, impact resistance, structural strength and serviceability. However, their thermal properties and fire performance have not been fully investigated. Therefore, in this research study thermal properties of two different types of MgO boards available in Australia were measured and their fire performance was investigated using three full-scale fire tests of LSF walls lined with two types of MgO board. Although the tests were conducted on two different types of MgO boards with different configurations, the fire test results gave a fire resistance level (FRL) of 30 min, in which the failure was initiated by integrity of the board with either board cracking or board joint opening. This paper presents the details of the thermal property tests and the three full-scale fire tests, and their results. In addition, the effects of different MgO boards, joint configurations and compounds, noggings, screw fastening techniques and cavity insulation on the fire performance of LSF walls are also presented.