Fire response of concrete structural members is dependent on the thermal, mechanical, and deformation properties of concrete. These properties vary significantly with temperature and also depend on the composition and characteristics of concrete batch mix as well as heating rate and other environmental conditions. In this chapter, the key characteristics of concrete are outlined. The various properties that influence fire resistance performance, together with the role of these properties on fire resistance, are discussed. The variation of thermal, mechanical, deformation, and spalling properties with temperature for different types of concrete are presented.

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Properties of Concrete at Elevated Temperatures

The effects of high temperature on compressive and flexural strengths of ordinary and high-performance concrete

Thermal and mechanical properties of fiber reinforced high performance self-consolidating concrete at elevated temperatures

Super absorbing polymers as an internal curing agent for mitigation of early-age cracking of high-performance concrete bridge decks

Critical factors governing the fire performance of high strength concrete systems

For use in fire resistance calculations, the relevant thermal properties of high-strength concrete (HSC) were determined as a function of temperature. These properties included the thermal conductivity, specific heat, thermal expansion, and mass loss of plain and steel fibre-reinforced concrete made of siliceous and carbonate aggregate. The thermal properties are presented in equations that express the values of these properties as a function of temperature in the temperature range between 0 and 1,000°C. 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 a significant influence on the thermal properties of HSC, while the presence of steel fiber reinforcement has very little influence on the thermal properties of HSC.

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Effect of temperature on thermal properties of high-strength concrete

In this paper, results from fire resistance experiments on five types of reinforced concrete columns are presented. The variables considered in the study include concrete strength [normal-strength concrete (NSC) and high-strength concrete (HSC)], aggregate type (siliceous and carbonate aggregate), and fiber reinforcement (steel and polypropylene fibers). Data from the study is used to determine the structural behavior of HSC columns at elevated temperatures. A comparison is made of the fire resistance performance of HSC columns with that of NSC and fiber-reinforced HSC columns. The factors that influence the thermal and structural behavior of HSC concrete columns under fire conditions are discussed. The results show that the fire resistance of a NSC column is higher than that of a HSC column. Also, the addition of polypropylene fibers and the use of carbonate aggregate improve fire resistance.

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Effect of Strength and Fiber Reinforcement on Fire Resistance of High-Strength Concrete Columns

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.

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

This paper presents the effect of various factors on the fire resistance of load-bearing, gypsum board protected, steel stud wall assemblies. A detailed experimental study was conducted to evaluate the fire resistance of 14 full-scale steel stud wall assemblies. Both single row and double row steel stud configurations with installation of gypsum board on each of the exposed and unexposed sides, and with and without insulation in the cavity, were considered in the experimental program. The insulation used were glass, rock and dry blown cellulose fibers. Data from the experimental program are used to determine the effects of stud-spacing, shear membrane, load intensity, resilient channel installation, insulation type and gauge thickness of studs on the fire resistance of gypsum board-protected, steel stud wall assemblies. Results from the studies show that the insulation type and number of gypsum board layers have significant influence on the fire resistance of steel stud wall assemblies.

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Factors Influencing Fire Resistance of Load-bearing Steel Stud Walls

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.

Mohamed A. Sultan

Papers

Effect of temperature on thermal properties of high-strength concrete

Effect of Strength and Fiber Reinforcement on Fire Resistance of High-Strength Concrete Columns

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

Factors Influencing Fire Resistance of Load-bearing Steel Stud Walls

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