# Special Issue on New Challenges in the Civil Structures for Fire Responses
###### Abstract  
Civil structures may be subjected to serious hazards during their lifespans, including natural hazards (i.e., earthquake, hurricanes, and tsunamis) and man-made hazards (i.e., fires and explosions). Fire is one of the most dangerous events, which can lead to environmental pollution, socioeconomic impacts, property losses, and even fatalities in the worst-case scenarios. Furthermore, sustainability and energy efficiency, which are main priorities in today's world, could highly increase the severity of fires in buildings, pushing the fields of fire protection and the innovation of structural materials to new frontiers and thus bringing new challenges with respect to the civil structures for fire responses. This topic is vital for guaranteeing adequate evacuation times and minimum safety conditions for firefighters, as well as minimizing the construction material resources used, economic costs, the loss of lives. Therefore, this Special Issue aims to address the new challenges in the fire safety procedures of buildings, especially in terms of the fire dynamics and fire responses of different construction materials (nanomaterials, geopolymers, mortars, concretes, and steels) and structural elements (anchors, panels, and slabs), based on experimental tests, numerical simulations, and/or analytical models. The editors thank all authors for their valuable contributions to the success of this Special Issue. Sixteen high-quality papers (including fifteen research papers and one review paper) were published based on research by more than fifty-five authors from across the world (including Europe, Asia, and Australia), representing fourteen different countries. 2022020  
[PERSON] and [PERSON] [3] present a risk index method for a more holistic approach to support decision making in fire safety strategies for buildings, especially industrial buildings. This method enables the identification of the impacts of different fire protection methods on the fire safety level of a building [3]. [PERSON] et al. [4] conducted experimental tests on protected steel columns with thermally enhanced fire protection mortars. The authors focused on the development of fire protection mortars and on the influence of their composition, aggregate size, and the addition of silica micro- and nanoparticles on their thermal performance. It was concluded that the gypsum-based mortars exhibited a great thermal response, with perlite playing an important role in the mitigation of the thermal cracking effect. Additionally, the addition of silica micro- and nanoparticles could still strongly improve their thermal insulation, but their dosages should be limited [4]. [PERSON] et al. [5] proposed an analytical model for estimating the effects of incident heat fluxes on structural elements due to travelling fire scenarios. The authors presented the assumptions and limitations of the developed model. The results obtained using the model were also discussed. This model is a remarkable tool, which can support designers in tackling structural fire engineering problems involving travelling fires [5]. [PERSON] et al. [6] proposed an egress model using a database and an artificial neural network model. Evacuation is a crucial safety measure that should always be well designed and planned, especially in high-occupancy buildings. The number of casualties in fire scenarios is strongly dependent on the evacuation planning. Correlations between the fire temperature and visibility, as well as toxic gas concentrations, were presented by the authors [6]. [PERSON] et al. [7] extended the scope of the application of the existing simplified method for determining the bending resistance of slim floor beams (SFB) under elevated temperatures to other steel section configurations, including the asymmetric double-T steel cross-sections, since the Eurocodes do not yet allow for the assessment of their fire resistance. The authors identified a wide range of steel cross-section configurations in which this method can be useful [7].