Fire resistance of reinforced concrete columns: A systematic review

Abstract

INTRODUCTIONCurrent codes for fire design of structures in the United States are still based on design at the component level using prescriptive requirements, although performance-based approaches can provide efficient alternatives for designing modern buildings with cost-effective solutions. To promote the use of performance-based approach in practice, there is a need not only to develop the necessary knowledge and modeling tools, but also to demonstrate and exemplify the benefits of this approach on the fire design of typical structures.This study compares the fire design of a typical office building using prescriptive and performance-based designs. The U.S. prescriptive approach is used as a benchmark for fire safety. This approach specifies the fire resistance rating required for each individual building structural elements, where the fire resistance rating is defined as the amount of time the element has to withstand when exposed to the standard fire. Then, alternative designs based on performancebased approach are studied. Evaluating the validity of the alternative designs requires the definition of a clear performance target. Here, it is assumed that the acceptable level of performance is the one that corresponds to the fire safety of the same structure designed based on the U.S. prescriptive guidelines. Under standard fire, the global stability of the structure should be ensured for at least the amount of time specified in the codes. Under natural fire, it is assumed that the global stability of the structure should be ensured until complete burnout of the fire.A 9-story office building with steel frames and regular plan configurations with a composite floor system is used as the prototype structure. In the first part, the International Building Code is used to obtain the required fire resistance rating for the building structural elements based on current practice. The Underwriters Laboratory publications (UL, 2003) ABSTRACT: Performance-based structural fire design provides a rational methodology for designing modern buildings with cost-effective solutions. However, in the United States, fire design still largely relies on design at the component level using prescriptive approaches. With performance-based approaches, there is an opportunity to benefit from increased flexibility and reduced cost in the design, but these advantages need to be explicitly described and disseminated to promote this shift in paradigm. In this paper, a comparative analysis is conducted on multi-story steel-concrete buildings designed following performance-based and U.S. prescriptive approaches. The steel-concrete composite structure allows taking advantage of tensile membrane action in the slab during fire, and therefore removing the fire protection on secondary beam elements. The nonlinear finite element software SAFIR ® is used to model the behavior of the buildings under the standard ASTM fire and a natural fire determined using the two-zone fire model CFAST. The numerical simulations show that performance-based design c...

Effect of fire on concrete mechanical properties and concrete columns

“…A concrete cover of at least 40 mm is required by several regulations for improved fire resistance. However, it has also been shown that thinner cover thickness results in fewer cracks, while higher cover thickness causes the cover to come off more quickly [31].…”

Fire Resistance of Eccentrically Loaded Reinforced Concrete Columns

“…At the same time, the plot shows the variation among various studies for same load eccentricities in determination of fire resistance. The data for this analysis can be seen in work of [6]. Fig.…”

Causal discovery and inference for evaluating fire resistance of structural members through causal learning and domain knowledge

“…Interestingly, these methods do not often agree if applied to a particular and/or a set of columns-possibly due to differences in derivation, principles, assumptions, and fundamentals. [40][41][42] The same also presents an opportunity to revisit the classical phenomenon of fire resistance of RC columns. Indeed, this is the second motivation behind this work.…”

“…The aforenoted methods deliver predictions on the expected fire resistance of RC columns given a set of variables. Interestingly, these methods do not often agree if applied to a particular and/or a set of columns—possibly due to differences in derivation, principles, assumptions, and fundamentals 40–42 . The same also presents an opportunity to revisit the classical phenomenon of fire resistance of RC columns.…”