Researches in Devision of Fire Safety

Multiscale Assessment of Polymer Pyrolysis for Fire-Spread Prediction: Experiments and Modelling (MAP-FIRE)

The reliable prediction of fire initiation and fire spread remains one of the central challenges in fire science. To address this challenge, computational fluid dynamics (CFD)-based fire models couple pyrolysis models with fluid dynamics, combustion and radiative heat transfer. A fundamental difficulty is the multiscale nature of the processes involved: relevant phenomena range from milligram-scale samples at the microscale to many kilograms at full scale. To date, no consistent modelling framework capable of bridging these scales has been established.

A major bottleneck is the determination of suitable input parameters for pyrolysis models. These parameters include decomposition kinetics as well as thermodynamic and transport properties. While some parameters can be measured directly, others—particularly reaction-kinetic parameters—must be derived from small-scale experiments using inverse modelling or analytical methods. Both approaches have specific limitations. Inverse modelling is computationally demanding and produces model-specific parameter sets, whereas analytical methods are faster but subject to more restrictive assumptions. In addition, the experimental measurement of intermediate products during multistep decomposition reactions and at high temperatures presents considerable technical challenges.

A further unresolved issue concerns the configuration of the models themselves. The coupling of the various sub-models within CFD-based fire models has not yet been investigated sufficiently, although interactions between sub-models are known to have a substantial influence on predictive accuracy. Existing experimental datasets are either restricted to specific scales or are of limited suitability for systematic model validation because of their complex material configurations. Consistently generated datasets covering multiple scales are currently lacking.

These limitations give rise to three central research gaps: the absence of a validated cross-scale parameterisation strategy, insufficient understanding of the influence of model configuration on predictive accuracy, and limited knowledge of the fundamental deficiencies of individual sub-models and their interactions. The MAP-FIRE project addresses these gaps through an innovative multiscale approach that has not previously been implemented in this form.

Funding organisation: German Research Foundation (DFG)

Funding period: 2026–2029

Contact: Felix Armbrust, M.Sc.

Investigation of the Influence of Ageing on the Fire Behaviour of Polymer-Based Fire Loads in Nuclear Facilities (AltBrandPoly)

Fires pose a significant threat to the operational safety of nuclear facilities. Electrical cables play a particularly important role in this context: they may themselves initiate a fire, for example as a result of short circuits, and may also contribute to fire spread. Because instrumentation, control and power cables perform safety-relevant functions, their failure during a fire may directly compromise the safety of nuclear facilities.

The polymeric sheathing, filling and insulation materials used in cables are subject to ageing processes caused by thermal, electrical, mechanical and environmental influences. It is not yet known precisely how the resulting material changes affect the risks of fire initiation and fire spread. This issue is becoming increasingly important in the context of service-life extensions for existing nuclear power plants in other European countries, in some cases to as much as 70 years.

CFD-based fire prediction models are increasingly used in safety assessments to estimate the consequences of fires. Among other processes, these models simulate the thermal decomposition, or pyrolysis, of solid materials. The associated pyrolysis models depend directly on material-specific input parameters. Age-related material changes therefore affect the model parameters directly and the predicted fire behaviour indirectly, with consequences for the reliability of such calculations that have not yet been fully clarified.

The research project aims to address these knowledge gaps. Small-scale thermoanalytical and calorimetric experiments, conducted alongside controlled artificial ageing, will be used to quantify the relevant ageing processes and their effects on fire behaviour. In parallel, CFD simulations performed using the Fire Dynamics Simulator (FDS) will be validated to assess the influence of ageing-induced material changes on fire predictions.

Project management agency: Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH; funded by the Federal Ministry for the Environment, Climate Action, Nature Conservation and Nuclear Safety (BMUKN)

Funding period: 2026–2028

Contact: Felix Armbrust, M.Sc.

Bio-Based Flame Retardants from Renewable Resources for the Fire Protection of Cross-Laminated Timber (FireSafe-CLT)

The FireSafe-CLT research project was established to expand the potential applications of cross-laminated timber in multi-storey timber construction. Owing to its versatility in walls, ceilings, floors and modular structures, cross-laminated timber (CLT) has become an important material in modern timber construction. The project aims to develop CLT products with excellent fire-performance and environmental characteristics.

The fire resistance of CLT is strongly influenced by the material thickness, the use of flame retardants and the properties of the adhesive systems employed. A particular challenge is preventing the delamination of individual timber layers under fire exposure. While melamine-urea-formaldehyde adhesives (MUF) exhibit high thermal resistance, polyurethane adhesives (PUR) are associated with an increased risk of bond-line failure at elevated temperatures. Because of potential emissions and concerns regarding the use of melamine, the research focuses on developing improved, heat-resistant PUR adhesive systems.

The project involves the development of innovative bio-based flame retardants derived from agricultural residues and by-products of wood processing. These materials will be incorporated into both adhesives and coatings to improve the fire-resistance performance of CLT components while further reducing the carbon footprint of the material. The use of renewable raw materials supports more sustainable construction practices and contributes to climate protection.

Comprehensive investigations will be conducted to achieve the research objectives. These include mechanical and physical testing at service temperatures, laboratory-scale experiments to assess the contribution of flame-retardant adhesives and coatings to fire behaviour, and investigations to evaluate the fire resistance of CLT components.

Funding: Funded by the Federal Ministry of Agriculture, Food and Regional Identity (BMLEH) through the Agency for Renewable Resources (FNR) under the Sustainable Renewable Resources funding programme (funding reference: 2224HV003 A to C).

Funding period: 2024–2027

Contact:  J. Rose, M.Sc.

Development of an Alternative Escape-Route Concept for Buildings and Vertical Extensions in Building Classes 4 and 5 (ALREKO)

The provision of additional housing in densely populated urban areas represents a major challenge for contemporary urban development. Vertical extensions to existing buildings are particularly important as a means of increasing urban density while minimising additional land consumption. However, one of the principal obstacles to implementing such extensions is often the provision of compliant escape and rescue routes.

The use of public traffic areas for vehicle parking, the presence of trees, or overhead lines for public transport can significantly restrict the ability of fire-service equipment to provide a second rescue route. Where rescue by the fire service cannot be ensured, a second structural escape route or a safety stairwell is generally required. In existing buildings, both solutions are often economically unfeasible, with the result that many potential vertical-extension projects have not been implemented.

The research project therefore investigates the measures required to upgrade a stairwell so that it can serve as the sole escape route without reducing the level of safety required by building regulations. Representative fire scenarios will be developed using risk analyses and numerical fire simulations. On this basis, performance-based escape-route solutions will be formulated for new and existing buildings in Building Classes 4 and 5.

This collaborative research project is being conducted by Rottenburg University of Applied Forest Sciences, Magdeburg-Stendal University of Applied Sciences and Technische Universität Braunschweig. Its objective is to develop economically viable and architecturally attractive solutions that fully maintain the safety level required under building regulations. The project will thereby create new opportunities for multi-storey timber construction by enabling vertical extensions that cannot be realised under current boundary conditions.

Funding: Funded by the Federal Ministry of Agriculture, Food and Regional Identity (BMLEH) through the Agency for Renewable Resources (FNR) under the Renewable Resources funding programme (funding reference: 2221HV089 A to C).

Funding period: 2023–2026

Contact:  J. Rose, M.Sc.

The aim of the research project is to develop and validate a reliable model with robust predictive capabilities for describing the effects of sprinkler systems on fire spread. The model is intended for use in performance-based fire safety assessments employing computational fluid dynamics (CFD) fire simulations.

Simulation-based methods are becoming increasingly important for special-purpose buildings, industrial facilities, and tunnels. However, existing CFD tools cannot yet directly represent the effects of sprinkler systems on the heat release rate because suitable validated models are currently unavailable. In practice, prescriptive approaches remain predominant, whereby sprinkler effects are represented only through a general reduction in the total heat released. Such approaches are often conservative and economically inefficient.

Moreover, the direct influence of sprinkler systems on fire dynamics—including changes in thermal conditions and the formation of water vapour and smoke layers—is not adequately considered, even though these phenomena are essential for assessing occupant safety.

The project will systematically investigate the mechanisms through which sprinkler systems influence fire development and will establish a physically based model suitable for fire safety assessments of transport infrastructure. This approach is expected to reduce the need for extensive and costly full-scale fire tests in the future.

The research combines numerical simulations with experimental investigations. The experiments will be conducted at the new Centre for Fire Research. Model validation will be performed by comparing the simulation results with calorimetrically measured heat release rates and other relevant fire characteristics.

Project management and funding: DLR Project Management Agency on behalf of the Federal Ministry for Economic Affairs and Energy, within the framework of the Industrial Collective Research programme (IGF). Research association: German Road and Transportation Research Association (FGSV).

Funding period / Project duration: 2025–2028

Contact: Martin Bogdahn, M.Sc.

Project sponsors: German Federation of Industrial Research Associations (AIF), FOSTA - Research Association for Steel Applications and industrial partners

Funding period/term: 2020 – 2023

Contact person: Shaghayegh Ameri, M.Sc.

In Germany, the market share of steel and composite construction in multi-story buildings is limited. The reasons are complex and related to the lack of experience to prejudices regarding fire safety. In addition, the cost-effectiveness of the construction method always plays a major role.

High fire-resistant, high load-bearing capacity and at the same time slender and economical composite columns can be manufactured with the aid of a Bar-Bundle made of reinforcing steel with a yield strength of 670 N/mm2, which is placed in a steel tube and filled with pressed mortar. By bundling bars, it is also possible to achieve high degrees of filling of the cross sections, with the load-bearing capacities comparable with much larger cross-section dimensions. Compared with composite columns with solid cross sections, bar bundle columns also exhibit more favorable heating behavior, since the individual bars are only in direct contact with each other at specific points and heat conduction between the bars is therefore limited. If the interaction of the bars is ensured at both room temperature and in the event of fire, these columns can be expected to exhibit significantly better load-bearing behavior than conventional composite columns with solid steel cores.

In a joint research project between the iBMB and the Technical University of Munich, the design and manufacturing of the columns and their load-bearing behavior are investigated by means of large scale tests at room temperature and under standard fire load (ISO 834). In addition, the material properties of high-strength reinforcing steel and mortar are to be determined at high temperatures.

Project sponsors: German Federation of Industrial Research Associations (AIF), FOSTA - Research Association for Steel Applications and industrial partners

Funding period/term: 2019 - 2021

Contact person: Shaghayegh Ameri, M.Sc.

As part of the energy transition and in response to climate change, the use of high-voltage energy storage systems (HVS) is increasing significantly across multiple sectors in Germany. However, reliable knowledge on the safe storage of large quantities of such systems was previously lacking. Fire incidents in Germany and abroad had already demonstrated their considerable hazard potential. The Federal Ministry of Education and Research (BMBF), represented by VDI, therefore funded the project “Management of Large-Scale Fires in Industrial Buildings Involving High-Voltage Energy Storage Systems and Their Fire-Spread Modelling (BEGIN-HVS)” within the programme “Research for Civil Security” and the funding measure “User-Oriented Innovation: Research for Civil Security II” under grant number 13N16604. The collaborative project partners were the Munich Fire Department, acting as coordinator, the Federal Institute for Materials Research and Testing (BAM), and several associated partners.

The project aimed to develop concepts for the safe storage of large quantities of high-voltage energy storage systems, addressing preventive and organisational fire protection as well as fire-service tactics during emergency response. The resulting technical recommendations were prepared for specific target groups, including emergency services, fire-safety authorities, planners and approving bodies responsible for the storage of lithium-ion high-voltage energy storage systems. They support the prevention of major fires through fire-protection solutions that are sufficiently safe, economically viable and operationally practicable. The results were published by the VB/G Technical Committee of the German fire services through AGBF/DFV as “2025-03a / Technical Recommendation on Preventive Fire Protection for the Storage of Lithium-Ion Batteries” and “2025-03b / Technical Recommendation on Operational Firefighting for the Storage of Lithium-Ion Batteries.”

At the Centre for Fire Research (ZeBra) at TU Braunschweig, large-scale fire tests were conducted on individual and multiple high-voltage energy storage systems arranged in representative storage configurations. The objective was to obtain experimental data on the fire behaviour and fire-spread characteristics of these systems. During the subsequent stages of the project, the test data were incorporated into numerical simulations and calculations to assess the safety level and the effectiveness of protective measures for large-scale industrial storage facilities.

The final report has been published by TIB and is available at: https://oa.tib.eu/renate/items/319086a6-654c-43ad-b276-bd880c477f3b

Project management agency: VDI; funded by the Federal Ministry of Education and Research (BMBF)

Funding period: 2023–2025

Contact: Justus Frenz, M. Sc.

The research project aims to develop an innovative hybrid structural component comprising standard rolled steel sections and high-performance timber elements, such as glued laminated timber, thereby combining the advantages of steel and timber. In analogy to partially encased composite beams, timber infill is inserted into the chambers of an I-section steel beam and connected to the steel section by means of shear connectors. The effective combination of standard steel sections and timber is intended to improve fire performance while increasing the load-bearing capacity. The hybrid components may be used both in new construction and in existing buildings up to Building Class 5.

Timber components are particularly valued for their natural character and sustainability. However, the strength of timber is several times lower than that of steel. Consequently, where high structural resistance is required, timber members must generally have comparatively large cross-sections. From a fire-safety perspective, timber also has a fundamental disadvantage compared with steel: it is a combustible construction material. This limits the application of structural timber systems in multi-storey buildings. Nevertheless, depending on the dimensions of the load-bearing timber cross-sections, timber members may achieve substantially longer fire-resistance periods than unprotected steel components. This is attributable to the low charring rate of massive timber elements. Under ambient-temperature design conditions, the thin-walled steel sections are also expected to provide significant advantages in terms of structural stability.

Short report, iBMB: KaF-FGF-2026-Scheller-Kammerholz

Short report, iVTH: https://www.ivth.org/content/download/aif/IGF-F22428N.pdf 

Project management agencies: German Federation of Industrial Research Associations (AiF) / DLR Project Management Agency

Research association: International Association for Technical Issues Related to Wood (iVTH)

Funding period: 2022–2025

Contact: Jan-Gabriel Scheller, M. Sc.

The fire resistance required by the building authorities for load-bearing, space-enclosing wall constructions made of highly thermal insulating bricks in advance of the market launch of these products is determined by extensive and cost-intensive fire tests on full-height walls in accordance with European harmonized test standards. Based on these tests, the fire protection classification is then given in the certification. Eurocode 6 in case of fire protection allows lower-cost computational verification methods, which are not yet possible for masonry construction with highly thermal-insulating bricks due to the lack of material parameters in the high-temperature range and due to unproven computational methods.

The aim of the research project is to determine the relevant thermal and thermo-mechanical material properties at high temperatures and, on this basis, to develop a validated simplified calculation method for determining the fire resistance of masonry components. This calculation method provides the prerequisites for determining the fire resistance of full-height wall constructions instead of time-consuming and expensive fire tests in the future, or reducing the number of required fire tests.

Project sponsor: German Federation of Industrial Research Associations (AIF) and industrial partners.

Funding duration/term: 2020 – 2023

Contact person: Lilia Maruhn, M.Sc.

The research project “Theoretical and Experimental Investigations to Extend the Design Basis for Different Types of Concrete under Natural-Fire Exposure,” funded by the German Research Foundation (DFG), generated extensive knowledge of the material behaviour of concrete during cooling following exposure to high temperatures. To address the remaining knowledge gaps, the DFG is funding further investigations.

For structural fire design, the current generation of the Eurocodes permits the use of natural-fire models in addition to the standard fire exposure defined by the standard temperature–time curve. Although temperatures in natural fires may temporarily exceed those prescribed by the standard temperature–time curve, they decrease once a substantial proportion of the fire load has been consumed, whereas the standard curve continues to rise. Design based on natural-fire models may therefore offer economic advantages.

When applying a natural-fire design approach, the load-bearing capacity of structural components and complete structures must be verified throughout the entire duration of the fire, including the cooling phase. Structural failure may occur during this phase as a result of delayed heating or excessive tensile stresses in the concrete. Owing to the thermal inertia of concrete, the outer regions of a cross-section begin to cool during the fire-decay phase, while the core initially continues to heat up.

The research project aims to conduct experimental investigations into the thermal conductivity and stress–strain behaviour of normal-strength concrete (CC) and high-performance concrete (HPC) during the cooling phase. The findings will be incorporated into constitutive material models for a generalised structural design approach.

Funding organisation: German Research Foundation (DFG)

Funding period: 2021–2023

Contact:  Jan Lyzwa, M. Sc.

Several German state building regulations, as well as the September 2019 Model Building Code, introduced provisions facilitating the use of timber construction. Under specified conditions, structural components that are required to be highly fire-retardant or fire-resistant may, by way of exception, be constructed from combustible materials. These components must demonstrate the required fire resistance with respect to load-bearing capacity and compartmentation and, together with their connections, must provide sufficient resistance to the spread of fire and smoke for the required period. This requirement relates particularly to smoke tightness.

To date, fire tests conducted in accordance with DIN 4102-2, DIN EN 1363 and DIN EN 1364 have not provided an objective assessment of smoke passage. DIN 4102-2, the European classification standard DIN EN 13501-2 and the European testing standard DIN EN 1363 provide only for a visual assessment of smoke passage, as specified in Clause 10.4.7 of DIN EN 1363. Neither a dedicated test method nor specific performance criteria are defined.

To enable objective verification of the compartmentation criterion required by building regulations, which also includes resistance to smoke spread, the research project aims to develop a test method for quantifying the passage of smoke and hot gases. The proposed performance criteria will be calibrated through comparative testing of conventional solid and lightweight construction components made from non-combustible materials. In addition to theoretical analyses, the project will focus primarily on experimental investigations.

Final report: https://www.irbnet.de/daten/rswb/25039000010.pdf 

Project management agency: German Institute for Construction Technology (DIBt)

Funding period: 2022

Contact: Jan-Gabriel Scheller, M. Sc.

Fires in electrical cable systems represent a safety-relevant hazard potential for nuclear plants in operation and in the process of dismantling. Due to technical failures in the form of arcing or short circuits, electrical cable systems entail an increased risk of fire. In addition, due to the flammable insulating materials used in cables, there is a risk of fire spreading from the original source of the fire to adjacent, separated areas, since cables are passed through space-enclosing components.

In the research project " Numerical and experimental investigations of polymer fires in nuclear facilities to improve the predictive capability of fire simulations " (FKZ: 1501565), fire simulation models for the application case "cable fire" are validated on the basis of small- and medium-scale fire tests. Furthermore, based on existing research results, an existing sub-model will be further developed to consider pyrolysis processes and extended for safety-related fire scenarios, e.g. under-ventilated fires.

This research project complements the international joint project OECD/NEA PRISME 3, in which large-scale fire tests are planned at the Laboratoire d'expérimentation des feux of the Institut de Radioprotection et de Sûreté Nucléaire in Cadarache. This international cooperation offers the possibility to compare the methods currently available or used nationally with methods based on other approaches. This enables us to assess and limit the reliability of our own methods.

Project sponsor: German Federal Ministry for Economic Affairs and Energy (BMWi) represented by the Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) gGmbH

Funding duration/term: 2018 – 2022

Contact person: Jens Spille, M.Sc.

Within the TIMpuls joint project, a complete science-based system is provided to enable the use of load-bearing and space-forming timber structures in multi-story to the high-rise buildings. The project aims to demonstrate that the use of the structures described in the joint project provides equivalent solutions in terms of fire protection compared with the masonry, reinforced concrete or lightweight steel structures commonly used today.

Sub-project 2 (funding code: 22006917) provides essential information on the fire resistance and natural fire behavior of wooden structural elements by means of experimental and numerical analysis on structural components and material tests. These results, in combination with the provided information on technical and preventive fire protection in the joint project, are integrated into a holistic risk assessment for multi-story timber buildings.

The provision of a construction catalog together with the integration of technical building equipment as the final result of the joint project which provides the basis for revising the building regulations - in particular the Model Building Code (MBO) and the Model Guideline on Fire Protection Requirements for Highly Fire Retardant Building Components in Timber Construction (M-HFHHolzR). The aim is to provide a regulated and performance-optimized use of timber construction up to high-rise limits, which allows the construction of economical and visually appealing timber structures.

Project sponsor: German Federal Ministry of Food and Agriculture (BMEL) on behalf of the Agency for Renewable Resources (FNR) Co-financing is coordinated by the Bavarian Carpenters' Guild Association (Landesinnungsverband des Bayerischen Zimmererhandwerks).

Website:  https://www.bgu.tum.de/timpuls/startseite/

Contact person: Sven Brunkhorst, M.Sc., M.Sc.

Download: KaF-FGF-2021-Sander-E-Mobilität.pdf

Download: Bericht_WNLA_Realversuche.pdf

Download: KaF-FGF-2021-Northe_NawaRo_Daemmstoffe.pdf

Within the framework of the research project funded by the German Research Association  (DFG) entitled "Theoretical and experimental investigations for extending the calculation basis of different types of concrete under natural fire exposure", extensive knowledge was gained on the material behavior of concretes in the cooling phase after exposure to high temperatures. In order to close remaining knowledge gaps, continued investigation is being funded by the DFG.

The research project aims to perform experimental investigations on the thermal conductivity and stress-strain behavior of normal concrete (CC) and high-strength concrete (HPC) during the cooling phase and to translate them into constitutive material models for a general design approach.

Project sponsor: German Research Association (DFG)

Funding duration/term: 2021 - 2023

Contact person: Jan Lyzwa, M. Sc.