Post-fire assessment and reinstatement of steel structures

Abstract

Purpose This paper aims to present technical aspects of the assessment method and evaluation of fire damaged steel structures. The current work focuses on the behavior of structural normal steel (hot-rolled and cold-formed) and high-strength bolts after exposure to elevated temperatures. Information on stainless steel, cast iron and wrought iron is also presented. Design/methodology/approach Because of the complexity of the issue, an elaborate presentation of the mechanical properties influencing factors is followed. Subsequently, a wide range of experimental studies is extensively reviewed in the literature while simplified equations for determining the post-fire mechanical properties are proposed, following appropriate categorization. Moreover, the reinstatement survey is also comprehensively described. Findings Useful conclusions are drawn for the safe reuse of the structural elements and connection components. According to the parametric investigation of the aforementioned data, it can be safely concluded that the most common scenario of buildings after fire events, i.e. apart from excessively distorted structures, implies considerable remaining capacity of the structure, highlighting that subsequent demolition should not be the case, especially regarding critical infrastructure and buildings. Originality/value The stability of the structure as a whole is addressed, with aim to establish specific guidelines and code provisions for the correct appraisal and rehabilitation of fire damaged structures.

Mechanical properties of High and Very High Steel at elevated temperatures and after cooling down

“…A tri-linear formula is found adequate for this scenario and an exponential one for the cold-formed steel. The results indicate good agreement with the proposed equations earlier presented by the authors (Maraveas et al, 2017). At last, it is suggested that the fire and the post-fire elastic modulus of HSS need further experimental investigation.…”

“…8(a-c). The predictive factors are also presented in the same figures for each mechanical property, as they have been proposed by Maraveas et al (2017). For the case of postfire material properties, a simple tri-linear model is proposed.…”

“…A motivating work towards this direction has been published recently by Maraveas et al (2017), describing the major aspects of the post-fire assessment and reinstatement of steel structures.…”

“…A useful discussion for the microstructure transformations is included in a previous work of the authors, where more details and illustrations are presented. One should have in mind, that the time-temperature-transformation diagrams, as presented by Maraveas et al (2017), demonstrate the resulting microstructures, taking into account the critical cooling and isothermal curves for three different steel types (hypereutectoid, eutectoid, and alloy steel).…”

Performance of steel moment‐resisting beam‐supporting column transfer structures under fire

“…The structural fire analysis can be performed based on a static or a dynamic approach. When a static approach is used, although the computational time may reduce, local buckling of the members may cause the failure time to reduce; hence, the results might be underestimated . On the contrary, when a dynamic approach is used, although the computational time is longer, the global stability is involved throughout the analysis, and the results are precisely determined based on different localized failure until the global failure occurs .…”