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.

Purpose: The current fire protection measures in buildings do not account for all contemporary fire hazard issues, which has made fire safety a growing concern. Therefore, this paper aims to present a critical review of current fire protection measures and their applicability to address current challenges relating to fire hazards in buildings. Design/methodology/approach: To overcome fire hazards in buildings, impact of fire hazards is also reviewed to set the context for fire protection measures. Based on the review, an integrated framework for mitigation of fire hazards is proposed. The proposed framework involves enhancement of fire safety in four key areas: fire protection features in buildings, regulation and enforcement, consumer awareness and technology and resources advancement. Detailed strategies on improving fire safety in buildings in these four key areas are presented, and future research and training needs are identified. Findings: Current fire protection measures lead to an unquantified level of fire safety in buildings, provide minimal strategies to mitigate fire hazard and do not account for contemporary fire hazard issues. Implementing key measures that include reliable fire protection systems, proper regulation and enforcement of building code provisions, enhancement of public awareness and proper use of technology and resources is key to mitigating fire hazard in buildings. Major research and training required to improve fire safety in buildings include developing cost-effective fire suppression systems and rational fire design approaches, characterizing new materials and developing performance-based codes. Practical implications: The proposed framework encompasses both prevention and management of fire hazard. To demonstrate the applicability of this framework in improving fire safety in buildings, major limitations of current fire protection measures are identified, and detailed strategies are provided to address these limitations using proposed fire safety framework. Social implications: Fire represents a severe hazard in both developing and developed countries and poses significant threat to life, structure, property and environment. The proposed framework has social implications as it addresses some of the current challenges relating to fire hazard in buildings and will enhance overall fire safety. Originality/value: The novelty of proposed framework lies in encompassing both prevention and management of fire hazard. This is unlike current fire safety improvement strategies, which focus only on improving fire protection features in buildings (i.e. managing impact of fire hazard) using performance-based codes. To demonstrate the applicability of this framework in improving fire safety in buildings, major limitations of current fire protection measures are identified and detailed strategies are provided to address these limitations using proposed fire safety framework. Special emphasis is given to cost-effectiveness of proposed strategies, and research and training needs for further enhancing building fire safety are identified.

Fire is one of the most severe conditions to which structures can be subjected, and hence, the provision of appropriate fire safety measures for structural members is an important aspect of design. The recent introduction of performance-based codes has increased the use of computer-based models for fire resistance assessment. For evaluating the fire resistance of steel structures, high-temperature properties of steel are to be specified as input data. This paper reviews high-temperature constitutive relationships for steel currently available in American and European standards, and highlights the variation between these relationships through comparison with published experimental results. The effect of various constitutive models on overall fire resistance predictions is illustrated through case studies. It is also shown that high-temperature creep, which is not often included in constitutive models, has a significant influence on the fire response of steel structures. Results from the case studies are us...

This paper presents the effect of temperature on the mechanical properties of high-strength alloy structural Q460 steel. The strength and stiffness properties of steel degrade with temperature and this deterioration has to be properly accounted for in the fire resistant design of steel structures. The strength and stiffness degradation is also influenced by the composition of steel. Because of a lack of data specific to high-strength Q460 steel, design standards assume the high temperature strength variation of Q460 steel to be same as that of conventional mild steel. To overcome this drawback, strength and stiffness properties of Q460 steel were measured at various temperatures in the range of 20–800°C. A relative comparison of measured data indicates that high-strength steel experiences a slower loss of strength and stiffness with temperature than conventional steel. Data generated from the experiments, namely, load-displacement relationships and vibration frequency, were utilized to develop rel...

The knowledge of high temperature thermal properties is critical for evaluating the fire response of concrete structures. This paper presents the effect of temperature on the thermal properties of different types of high-strength concrete (HSC). Specific heat, thermal conductivity, and thermal expansion are measured for three concrete types, namely, HSC, self-consolidating concrete (SCC), and fly ash concrete (FAC), in the temperature range from 20–800°C. The effect of steel, polypropylene, and hybrid fibers on thermal properties of HSC and SCC is also investigated. Results from experiments show that SCC possesses higher thermal conductivity, specific heat, and thermal expansion than HSC and FAC in the 20–800°C temperature range. Data generated from tests is utilized to develop simplified relationships for expressing different thermal properties as a function of temperature. The proposed thermal property relationships can be used as input data for evaluating the response of concrete structures under fire ...

Results from fire resistance experiments on six RC beams are presented in this paper. The test variables included concrete strength (permeability), support conditions, fire scenario, and load ratio. Data from fire tests are used to illustrate the comparative performance of high strength concrete (HSC) and normal strength concrete (NSC) beams under fire conditions. Also, data from the tests is used to validate a macroscopic finite-element model specifically developed for tracing the fire response of RC beams. Results from the tests and numerical studies show that HSC beams have lower fire resistance than that of NSC beams. It is also shown that HSC beams exhibit higher levels of spalling which is largely influenced by the permeability of concrete, type of fire exposure, load level, and restraint conditions. Similarly, the type of fire scenario, axial restraint, and load level have significant influence on the overall fire resistance of RC beams. These factors are to be considered for evaluating the fire re...