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Test results: yield stress and tensile strength of reinforcement steel at high temperatures

The conspicuity of six different firefighting garments was measured, from the back and from the side, and at two different positions. The experiment serves as a demonstration of the newly developed technique to quantify conspicuity. The results show that the conspicuity of firefighting garments is indeed measurable. The conspicuity of the six garments differs by up to a factor of two. The conspicuity also depends strongly on the visual environment - three times more shading resulted in a two to three times decrease in visual conspicuity. The TNO conspicuity method is a powerful tool to quantify the effective visibility of firefighter garments.

Vijf brandweerkleding fabrikanten leverden kleding in alle beschikbare maten. Maatvoering verschilde zo sterk dat een persoon jasmaat XS van een fabrikant had en maat L van een andere. Bepleit wordt voor standaardisatie

Modern societies are increasingly dependent on a set of critical products and services which comprise the Critical Infrastructure (CI). This makes Critical infrastructures increasingly important as a planning factor in case of emergencies. For that reason, we studied a number of emergencies and a small set of local emergency plans from the perspective of how first responder currently take critical infrastructures into account. Our initial analysis indicates that civil emergency plans lack consideration for critical infrastructures. First responders, such as police and fire brigades, are often unaware of that their operations and non-evacuated citizens depend on critical infrastructure. Therefore, we recommend that emergency preparedness plans, training, situational awareness, and the decision-cycle of first responders and emergency management need to pay more attention to critical infrastructures. This decreases the risk that emergencies are worsened due to second-order effects of failing infrastructure, that emergency operations themselves are hampered, and that more casualties occur

In order to obtain reliable data on the generation of toxic combustion products and to get more insight into the risks of fires in pesticide warehouses TNO performed the research project 'Toxic combustion products from pesticide fires'. The following research activities have been performed during the project: — A study of the casuistry of pesticide fires; — A literature study of small scale combustion test methods; — Execution of medium scale combustion experiments with pesticides; — A study on the extrapolation of the emissions of small and medium scale combustion tests to real fire conditions; — A study on the prevention and control of fires in pesticide storages. Most important results and conclusions of the project. — The medium scale combustion experiments with parathion, chlorfenvinphos, dichlobenil and 2,4-D indicate the following: — Emissions of solids (particles and soot), carbon monoxide and hydrocarbons are higher than assumed in present hazard assessment studies; - Emissions of nitrogen oxides and chlorinated dioxins and furans are lower than assumed in present hazard assessment studies; - Chlorine and sulphur in the pesticide are nearly fully converted into hydrogen chloride and sulphur dioxide; - The emissions of ammonia, chlorine and phosgene are below or just above detection limits; - Large quantities of solid residues remain in all fires. The residues contain up to 10% unburnt pesticide; - Simulated fire extinguishing or oxygen deficiency do not significantly influence the emissions during the medium scale experiments. — Similarity requirements to extrapolate the emissions to pesticides other than those investigated have been determined. As these similarity requirements will not be completely fulfilled in many cases the uncertainties in the extrapolated emissions are large. — The conservative conversion rates are proposed for a pesticide fire. Fire protection systems — A methodology has been developed to define the required fire protection level of a pesticide storage: - The required fire protection level for a pesticide storage depends on the product fire hazard, the packaging fire hazard, and the environmental and health hazard of the stored materials; - Four fire protection levels for a pesticide storage are distinguished in the methodology, with fire protection levels having different requirements. For level one only the basic minimum requirements like good facility lay out, ignition source control, good housekeeping and regular training of employees are necessary. The highest protection level is level four. For level four automatic fire alarms, sprinkler systems and a basin for extinguishing water are additional requirements. — Application of this methodology is recommended to obtain a cost effective protection level for a pesticide storage taking into account the hazards of the stored pesticides. Small scale test methods — Based on the results of the study on the characteristics of small scale test methods it can be concluded that the applicability of small scale test methods to predict the emission of toxic products of a pesticide fire is very limited. — Small scale methods should be further developed in order to improve the simulation of the fire conditions observed during the medium scale experiments. Case histories — Due to the very general description of the case histories it was impossible to get reliable data on the causes, development and consequences of pesticide fires.

Over the last six years, CEN TC 127 and more in particular its working groups ad hoc 14 and ad hoc 7 have been active in evaluating and improving the reproducibility of fire resistance testing. Ad hoc 14 developed a draft procedure for the evaluation of the performance of fire resistance furnaces in 1994. The two working groups were subsequently responsible for an extensive series of proving tests aimed at evaluating the procedure, but also at investigating the possible role of the Plate Thermometer in harmonising thermal exposure. The results of the work are that, when furnaces are controlled using small diameter sheathed thermocouples, the thermal exposure of a test specimen differs greatly over the various furnaces. Controlling the furnaces on Plate Thermometer readings brings thermal exposures much closer together. This paper gives an overview and a quantitative explanation of the findings.

Metamorphic petrology is a branch of geology that deals with the study of changes in rocks due changing physio-chemical conditions. As conditions shift in or out of the thermodynamic stability field of phases, new phases may appear whereas others disappear. A basic approach is mapping of so-called isograds, which are lines separating the occurrence of (combinations of) phases in the field. Concrete is a poor conductor of heat, but can suffer considerable damage at elevated temperatures or when exposed to fire. Unravelling the heating history of concrete is important to forensic research or to determine whether a fire-attacked concrete structure and its components are still structurally sound. Analogous to metamorphic petrology, thermally triggered reactions in concrete resulting in changes in specific phases may be used to trace isograds. As these occur in response to temperature alone, they may be used to trace temperature variations in concrete with depth. Concrete petrography is a quick and a well-suited method for unravelling the heating history of concrete. The method involves a combination of visual inspection and the use of microscopic methods in a systematic way to study the thermally affected concrete. It is a powerful diagnostic tool that has successfully been applied in routine research and testing of concrete lining in tunnels, assessment of fire-damage to structures and evaluation of fireproofing in waste incinerators

To be able to predict which persons are capable to perform under acute stress is important for the selection and training of professionals in the military, police, and fire- fighting domain. The present study examines how individual differences in coping (style, efficacy, and behavior) explain differences in performance and anxiety under acute stress. Cadets (n = 124) of the Netherlands Defence Academy were examined during a realistic stressful exercise. Person characteristics obtained from questionnaires well before the exercise were related to performance and behavior indices obtained during the exercise. Coping style predicted anxiety and performance, which was mediated by behavior during the exercise.

This paper gives an overview of the structural behaviour and design of aluminium structures exposed to fire conditions. Two design approaches are elaborated: the "traditional" approach that is mainly based on conventions and the fire safety engineering approach that is more based on physics. For the traditional approach, equations for the aluminium member temperature are provided, mechanical properties are given and recently developed calculation models for flexural buckling, local buckling and heat affected zone rupture are presented. For the fire safety engineering approach the possibilities for evaluation of member temperature are provided, a constitutive model for aluminium alloys is given which can be implemented in finite element programmes and two design examples are presented to show the evaluation of the structural behaviour. The paper concludes that the fire safety engineering approach is preferred for the fire resistance evaluation in particular for structures made of materials sensitive to fire conditions, such as aluminium alloys.

Distribution and storage of liquefied pressurised gases is a critical safety issue, often resulting in a very high individual and societal risk, at least in densely populated zones. Several risk assessments pointed out that this is mostly due to the possible occurrence of a Boiling Liquid Expanding Vapour Explosions (BLEVE) of the tank that may be exposed to an intense fire as a consequence of release scenarios. In the present work, a modelling approach is presented for the calculation of fired BLEVE probability. Simplified models were obtained for the estimation of the vessel time to failure with respect to the radiation intensity on the vessel shell. The time to failure was compared to a reference time required for effective mitigation actions and thus related to the escalation probability. The analysis of the effect of protective measures, such thermal insulating coating and pressure relief devices, on the time to failure allowed the identification of the necessary requirements for effective BLEVE prevention.

In order to study buckling of fire exposed aluminium columns, a finite element model is developed. The results of this model are verified with experiments. Based on a parametric study with the finite element model, it is concluded that the simple calculation model for flexural buckling of fire exposed aluminium columns in EN 1999-1-2 does not give an accurate prediction of the buckling resistance in fire. This paper proposes an alternative design model, which takes into account the shape of the stress-strain relationships of aluminium alloys at elevated temperatures. Predictions of this model agree well with that of the finite element model. © 2009 Elsevier Ltd. All rights reserved.

The modelling of consequences of releases of hazardous materials in the Netherlands has mainly been based on the “Yellow Book”. Although there is no updated version of this official publication, new insights have been developed during the last decades. This article will give an overview of new developments in consequence modelling, focussing on fire modelling

Concrete is a poor conductor of heat. Nevertheless, heating of concrete results in physico-chemical conditions shifting in or out the thermodynamic stability field of specific phases (minerals) in the concrete, effectuating their (dis)appearance. Metamorphic petrology is a branch of geology that deals with the study of such changes; as a basic approach to unravel the heating history of rocks, domains with phases (minerals) specific for a set of discrete physico-chemical conditions are delineated (mapped). Unravelling the heating history of concrete is important to forensic research or to determine whether a concrete structure subjected to fire and its components are still structurally sound. Analogous to metamorphic petrology, thermally triggered reactions in concrete result in changes in specific phases which may be used to trace isograds. In the case of heated concrete, these occur in response to temperature alone, and may hence be used to trace temperature variations in concrete with depth (isograds). The method involves a combination of visual inspection and the use of microscopic methods in a systematic way to study the thermally affected concrete. It is a powerful diagnostic tool that has successfully been applied in research and testing of concrete linings in tunnels, assessment of fire-damage to structures and evaluation of fireproofing in waste incinerators

Fire safety of buildings and structures is an important issue, and has a great impact on human life and economy. One of the processes negatively affecting the strength of a concrete building or structure during fire is spalling. Many examples exists in which spalling of concrete during fire has caused severe damage to structures, such as in the Mont Blanc and Channel Tunnel. Especially newly developed dense types of concrete such as HPC and SCC, have shown to be sensitive to spalling, hampering the application of these new concrete types. To reduce risks and building costs, the processes behind spalling need to be understood. Increasing our knowledge allows us to reliably predict the behaviour and take effective and cost friendly preventive measures. Moisture present in concrete is one of the reasons for spalling. When concrete is heated water will evaporate, which results in a high gas pressure inside the pores of concrete. This high gas pressure can induce spalling. To attain a better understanding of this process, a first step was taken to develop a finite element model (FEM) describing this transport of moisture in heated concrete. However, the validity of all current models (including our own) is unknown because of debatable input parameters and lack of experimental techniques to follow the transport process in situ. In cooperation with the Eindhoven University of Technology moisture transport in heated concrete can now be investigated with a home built dedicated 1D Magnetic Resonance Imaging (MRI) setup. Using the results of the MRI experiments the validity of our FEM models has been assessed for the first time. A general correspondence is observed. The FEM model described in this paper is a simplified FEM model compared to literature models. Already this simplified model shows a good correspondence with the MRI measurements.

Design models for local buckling of fire-exposed aluminum sections are currently lacking. Based on analyses with validated finite-element models, this paper investigates local buckling of extruded sections with stress-strain relationships representative for fire-exposed aluminum alloys. Due to the fact that these stress-strain relationships are more curved than at ambient temperature, existing design models developed for ambient temperature cannot be used for fire design. This paper presents a new design model for local buckling under fire conditions. The study concludes that the local buckling resistance decreases less fast than the plastic capacity at increasing temperature. This is mainly due to the fact that the ratio between the modulus of elasticity and the 0.2% proof stress increases with increasing temperature for structural aluminum alloys. © 2010 ASCE.

This study examined the effect of active pre-warming on speed and quality of performance during simulated firefighting exercise. Twelve male firefighters performed two trials in counterbalanced order. They were either pre-warmed by 20-min cycling at 1.5 Watt kg-1 body mass (WARM) or remained thermoneutral (CON) prior to a simulated firefighting activity. After the pre-warming, gastrointestinal temperature (P < 0.001), skin temperature (P = 0.002), and heart rate (P < 0.001) were higher in WARM than in CON. During the firefighting activity, rating of perceived exertion, thermal sensation and discomfort were higher for WARM than for CON. Finish time of the firefighting activity was similar, but the last task of the activity was completed slower in WARM than in CON (P = 0.04). In WARM, self-reported performance quality was lower than in CON (P = 0.04). It is concluded that pre-warming reduces the speed during the last part of simulated firefighting activity and reduces self-reported quality of performance. © 2014 Elsevier Ltd and The Ergonomics Society.