Mohamed A. Sultan

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.

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.

Fire Resistance Performance of Lightweight Wood-Framed Assemblies

There are extensive efforts underway around the world, including those by the National Research Council of Canada (NRC), to develop fire resistance models. NRC is currently developing thermal and structural models for lightweight wood-framed assemblies, in collaboration with the Canadian wood industry. These models will be used in NRCs risk-cost assessment models as well as in the development of fire resistance design equations. To aid the development of fire resistance models, NRC has just completed, as a first step, a literature review on the efforts made to predict the fire resistance of lightweight wood-framed assemblies, with the objective of determining the gaps that need to be filled. This paper presents the results of this literature review, which include: standard versus real time-temperature fire curves, experimental studies, available fire resistance models and design methods and the identification of their limitations, charring of wood, and material properties of assembly components at elevated temperatures.

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.

THERMAL PROPERTIES OF HIGH STRENGTH CONCRETE AT ELEVATED TEMPERATURES

In recent years, high strength concrete (HSC) has become at attractive alternative to traditional normal strength concrete (NSC). With the increased use of HSC, concern has developed regarding the behaviour of such concrete in fire. Studies are in progress at the National Research Council of Canada for developing design guidelines for the use of HSC under fire conditions. The behaviour of HSC columns is illustrated by comparing the fire resistance performance of HSC columns with that of NSC columns. Results from experimental studies that were carried out to determine the thermal properties of HSC, with and without steel fibre-reinforcement, at elevated temperatures are also presented. The effect of temperature on thermal conductivity, thermal expansion, specific heat and mass loss of HSC is discussed. Test data indicate that the type of aggregate has significant influence on the thermal properties of HSC, while the presence of steel fibre-reinforcement has very little influence on the thermal properties of HSC.

The Effect of Furnace Parameters on Fire Severity in Standard Fire Resistance Tests

This paper discusses the predicted results obtained from models developed to determine the effects of furnace depth (2.5 m and 0.5 m), type of furnace lining material type (fireclay brick, insulating firebrick and ceramic fibre insulation) and type of fuel (gas or liquid) on fire severity in fire resistance test furnaces using the CAN/ULC-S101, ASTM E119 and ISO 834 time-temperature relationships. The type of fuel used in the furnace and the type of furnace wall lining material significantly affected the heat absorbed by the test specimen while the furnace depth effect was minimal when the furnace was lined with ceramic fibre insulation. Factors to improve the repeatability and reproducibility of the fire severity in fire resistance test furnaces are provided.

Optimum location for fire alarms in apartment buildings

Measurements on the alarm sound distribution in nine apartment buildings showed that if adequate awakening potential is to be provided for sleeping residents, an alarm sounding device must be located within each apartment. Information on the minimum sound level necessary to awaken such a sleeping person is also given. A procedure that can be used to determine sound attenuation within apartment buildings is presented. Examples to demonstrate such a procedure are provided.

Correlation between the severities of the ASTM E119 and ISO 834 fire exposures

The temperature rise in a castable refractory brick specimen of well-defined thermal properties was used to develop a correlation between the severities of the ASTM E119 and the ISO 834 fire tests. It was found that the ISO fire test is slightly less severe than the ASTM test, but the gain in fire endurance on account of conducting the test according to the ISO standard is usualy five minutes or less.

Performance of wood stud shear walls exposed to fire

This paper presents the results of seven full-scale fire resistance tests conducted on load-bearing gypsum board protected, wood stud shear wall assemblies. The experimental studies were conducted to determine the effects of placement of shear membrane and type of insulation on the fire resistance of such assemblies. Details of the results, including the temperatures and deflections measured during the fire tests, are presented. Results from the studies indicate that the placement of shear membrane and insulation type significantly influence the fire resistance of such wood stud shear wall assemblies.

Review of the Punching Shear Behavior of Concrete Flat Slabs in Ambient and Elevated Temperature

There are a number of benefits associated with two-way concrete flat slab construction for office buildings, parking garages and apartments - for example, reduced formwork, prompt erection, flexibility of partitions, and minimal increase in story heights. However, concrete flat slabs could be quite vulnerable to punching shear failure in the event of a fire. The objective of the present article is to provide a state of the art review of the existing research and the issues associated with concrete flat slabs in fire and elevated temperature. There are a number of experimental and analytical studies on the punching shear behavior of concrete flat slabs in ambient conditions, available in the literature. Based on these studies, it is found that punching shear capacity in ambient condition is affected by many factors, which may not remain constant during a fire exposure. Only a limited number of studies on concrete flat slabs for punching shear failure in fire are available. This paper reviews the available ...