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The most important component of passive fire protection of buildings is fire resistance, which is designed to prevent spread of fire and structural collapse in fire. In this paper, results from fire resistance experiments on eight different types of reinforced columns (RC) are presented. The study was undertaken to study the effect of concrete strength, confining reinforcement and the configuration of confining reinforcement on the fire resistance of RC columns. The results show that these parameters of confinement have a marked role to play in the fire rating of the reinforced concrete columns. The disadvantage of high strength concrete being prone to spalling can be mitigated by the enhanced confinement of the RC columns. A simplified design equation, to determine effect of confinement on fire resistance of RC columns, has been arrived at. [ABSTRACT FROM AUTHOR]

Fire has a significant influence on concrete structures and members. A concrete column, compared to other structural members, has most often to cope with vertical forces and bending moments from slabs and beams. Therefore, it is important to investigate the fire resistance of concrete columns. In fact, simplified methods are often adopted to evaluate the capacity of concrete columns. In the fib Model Code 2010, a curvature approximation is introduced. However, this method has not been validated to be used in case of fire. Hence, a parametric study is performed in this paper to investigate the application of this method. As a first step of this paper, a curvature approximation formula used at ambient temperature is introduced. As this formula is based on the curvature and in order to verify the application, a numerical tool that can obtain the bending moment and curvature relationships is presented and validated. Further, an ISO 834 standard fire is adopted. Finally, parameters like dimensions, the reinforcement ratio and the slenderness ratio are investigated. Comparing the effect of dimensions, the reinforcement ratio as well as the slenderness ratio, it is concluded that only the slenderness ratio has a significant influence on the column capacity with the proposed formula. The difference between the deflections obtained with the simplified method and the numerical values increase in function of the slenderness ratio (in case of the same axial load). However, this method is proven to be easy-to-use and safe for the prediction of the fire resistance of concrete columns. [ABSTRACT FROM AUTHOR]

Uncommon structural fire engineering designs must demonstrate adequate safety, in principle, through a balancing of the uncertain future costs and benefits of safety investments. In structural design for normal load conditions (‘ambient design’) this level of detail is commonly avoided through the application of reliability targets. In order to inform the development of reliability targets for structural fire design, the background of the ambient reliability targets is discussed. It is found that different common ambient reliability targets are broadly comparable when taking into account differences in assumptions and applications. As recent reliability targets have been informed by simplified cost-optimizations, the derivation of such a model is presented. The derivation allows identification of possible pitfalls when extending ambient reliability targets to structural fire design. It is concluded that ambient safety targets cannot readily be scaled as a function of the fire occurrence rate for application to structural fire engineering problems. The underlying cost-optimization model is, however, applicable as a concept. A number of issues requiring further attention are identified. [ABSTRACT FROM AUTHOR]

In recent years there has been a growing interest in analyzing the contribution of pavements to fire growth for improving safety in tunnels. However, only few analyses take into account or quantifying toxic gases emitted during the pavement burn out. In this study, simultaneous cone calorimeter and FTIR analyses were conducted to evaluate the contribution to fire growth of two different types of fireproof pavements (concrete and asphalt) obtaining averaged values of heat release rate per unit area of 0 and 50 kW/m 2 respectively. The CO released was monitored as a valuation of how complete is the combustion taking place and also to compare the toxic potential of such materials. Further approximated ignition temperatures of asphalt in the range of 420–450 °C were also obtained. The results indicate that concrete pavement do not contribute to fire growth since no ignition was observed while asphalt pavement contributes similarly to other components generally found in vehicles. Very opaque fumes with significant concentrations of CO were detected during asphalt pavement combustion. Severe thermal degradation was observed in the asphalt pavement samples, including calcination and the detachment of aggregates while on the surface of concrete pavement samples just some minor cracks were reported. [ABSTRACT FROM AUTHOR]

This paper presents the results of a research project to study the seismic resistance of fibre reinforced polymer (FRP) strengthened concrete members after fire exposure. Specifically, the paper presents results of FRP strengthened reinforced concrete columns exposed to a standard fire including temperatures measured during the test and a discussion of the loads applied to the columns. Finally, the paper also presents the impact of lateral loading on structural columns after fire to assess the effectiveness of structural resistance of fire-damaged FRP strengthened building elements in case of an earthquake. Numerical models to simulate the lateral behaviour are presented and the predictions are compared to the test results. Since the FRP strengthened columns were insulated with fire protection, the lateral load resistance of the unstrengthened column was reduced by less than 5% due to fire exposure. [ABSTRACT FROM AUTHOR]

Recent years have seen widespread success applying fibre-reinforced polymer (FRP) materials for internal reinforcement and externally bonded strengthening of concrete structures. However, considerable reductions in mechanical and bond properties of FRP materials at elevated temperatures continue to hinder their application in buildings, where structural fire-resistance ratings are typically required. To meet currently imposed fire safety requirements, FRP materials often require supplemental fire protection insulation or thick concrete cover to maintain their temperature below an assumed (though not currently well-defined) 'critical' value during an assumed standard fire exposure. Such requirements are based on a definition of structural fire resistance that is rooted in a prescriptive framework and that fails to take advantage of the state of the art in performance-based structural design for fire safety. This paper is intended to present a summary of the state of the art in this area and also to demonstrate clear opportunities for internal FRP reinforcement and external FRP strengthening of concrete elements that may arise from taking a performance-based fire safety design approach. [ABSTRACT FROM AUTHOR]

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Canadian Journal of Civil Engineering is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Nowadays, fire remains a risk with potentially severe consequences for most buildings and structures. In fact, beyond the physical damage to the structure, which may require their subsequent repair or demolition, the fire also implies risks for the safety of occupants. Concrete exposure to high temperatures causes a progressive physical and chemical degradation that changes its microstructure and properties. Experimental studies have already been carried out on different types of concrete, under temperature increase. Lightweight, standard and high strength concrete, reinforced with various types of fibers has already been studied. The various types of concrete have shown significant differences in their behavior. However, the behavior of concrete containing cork was not yet studied. In the present study, cork concrete specimens were subjected to high temperatures (ranging from 90°C to 600°C). The specimens were produced replacing the amount of sand from a reference composition with several percentages (20, 25, 30 and 40%) of a mixture of granulated cork expanded. The results were analyzed and compared with those obtained for identical concrete samples that were not subjected to heating. The results revealed that the presence of cork has a beneficial effect on the residual strength of concrete subjected to high temperatures. Despite the reduction of concrete strength with increasing temperature, concrete batches with higher cork amounts reported lower percentage strength reduction. [ABSTRACT FROM AUTHOR]

Abstract: A new performance-based assessment approach for structures in fire, referred to as hybrid fire testing (HFT) method, is presented in this article. The HFT was developed based on a sub-structuring method, by dividing the whole structure into two substructures, one being tested in a furnace and one being simulated by a computer. This represents a form of “hardware-in-the-loop” simulation. Using HFT, the performance of the whole building can be evaluated at a very reasonable cost, significantly less than the cost of the direct whole building test. More reliable results than the prescriptive method can also be achieved with comparable and even more comprehensive results than that of a direct full-scale test. A 6-storey reinforced concrete building was designed, as a prototype for application of the hybrid fire testing approach. Two fire scenario examples were considered; a 6-storey building with a fire compartment on the first floor, in the center of the building and a 6-storey building with a fire compartment on the third floor. The two substructures for these two HFT scenarios were; one the column in the fire compartment and two the rest of the building. This paper includes the description of the hybrid testing methodology, details of the 6-storey building prototype and the methodology verification. Using the HFT approach, various scenarios could be explored to couple modeling and testing globally. This may also provide the possibility of running one test in a testing facility, e.g. NRC's, and running the analysis remotely at a different location. This would make furnace facilities more accessible to the research communities around the globe. [Copyright &y& Elsevier]