När byggnadsdelars brandmotstånd provas och klassificeras används nästan enbart standardbrandkurvan som definierad temperaturexponering över tid. Brandexponeringen beskrivs i den europeiska standarden EN 1363-1 samt den internationella standarden ISO 834. Standardbrandkurvan definierades för över 100 år sedan i en tid när kunskapen om branddimensionering var bristfällig. Dagens standardbrandkurva är till viss del modifierad men ser i stort sett ut på samma sätt som för 100 år sedan. Ett annat sätt att dimensionera byggnadsdelar på är teoretiskt med hjälp av de parametriska brandkurvorna och materialmodellerna i Eurokoderna. I EN 1991-1-2 bilaga A presenteras en beräkningsmetod, Eurokodmodellen, som resulterar i temperatur-tidkurvor. Denna metod tar hänsyn till hur den slutgiltiga rumsgeometrin och brandlasten ser ut och till skillnad från standardbrandkurvan innehåller den dessutom en avsvalningsfas. Därav anses de parametriska brandkurvorna beskriva verkliga bränder bättre än vad standardbrandkurvan gör. I detta arbete har temperaturutvecklingen i lägenhets- och rumsbränder, baserade på riktiga lägenhetsgeometrier, beräknats med Eurokodmodellen i syfte att jämföra temperatur-tidkurvorna med standardbrandkurvans temperaturexponering. Arbetet påbörjades med en litteraturstudie för att ge en djupare förståelse inom ämnet. Därefter samlades ritningar in från riktiga lägenheter som låg till grund för ett ritningsunderlag. Ritningsunderlaget användes sedan som input till beräkningsmetoden i EN 1991-1-2 bilaga A. För att underlätta beräkningarna skapades ett beräkningsdokument i Excel enligt Eurokodmodellen, där alla beräkningarna genomfördes. Fyra olika scenarier skapades som innefattar två olika termiska trögheter samt två olika öppningsfaktorer för varje termisk tröghet. Anledningen till det var att det ansågs intressant att beakta i vilken utsträckning dessa två parametrar påverkar brandförlopp. Det resulterade i att scenario 3 med lägre termisk tröghet och högre öppningsfaktor var det scenario med kraftigast brandförlopp avseende tillväxthastighet och temperatur. I förhållande till standardbrandkurvan hade majoriteten av temperatur-tidkurvorna för scenario 3 en snabbare upphettningsfas med högre temperaturer fram till påbörjad avsvalningsfas. Scenario 2 med högre termisk tröghet och lägre öppningsfaktor resulterade i det motsatta, det vill säga ett längre brandförlopp med lägre temperaturer. Vid en jämförelse visar det sig att för majoriteten av kurvorna enligt scenario 2, så var temperaturen lägre än standardbrandkurvans under hela brandförloppet. Öppningsfaktorn styr vilken mängd syre som kommer in i brandrummet, en högre öppningsfaktor betyder mer syre och intensivare brandförlopp. Termiska trögheten reglerar hur långsamt brandrummet värms upp, en låg termisk tröghet innebär att brandrummet värms upp snabbare och resulterar därmed i högre temperaturer då mindre energi absorberas av väggarna. De beräknade lägenhets- och rumsbrändernas temperatur-tidkurvor stämde överlag bättre överens med standardbrandkurvan än förväntat. Givet att golv och tak är betong och väggar gips samt att brandlasten som definierats av Boverket är korrekt, är slutsatsen att standardbranden fungerarar bra i de flesta fallen. Dock är tillväxthastigheten i standardbranden lägre i vissa av scenarierna men har i många fall en temperatur vid 60 minuter som överstiger scenariernas. Det finns dock utrymme för utveckling av brandmotståndstester då en mängd av de beräknade lägenhets- och rumsbränderna översteg standardbrandkurvan under tidsperioder på över 30 minuter, något som hade kunnat äventyra de brandskyddstekniska kraven. Men eftersom majoriteten av de beräknade bränderna understeg standardbrandkurvan kan kraven och standardbrandkurvan oftast anses överdimensionerade utifrån genomfört arbete. / When construction parts are tested in order to try and classify the fire resistance, the standard fire curve is almost only used. The standard fire curve defines exposure from temperature over time. The fire exposure is described in the European standard EN 1363-1 and in the international standard ISO 834. The standard fire curve was defined for over 100 years ago, in a time when the knowledge in fire design was inadequate. Now days the standard fire curve is a bit modified, but it almost remains the same as the fire curve defined for 100 years ago. Another way to design construction parts is theoretical by using parametric fire curves and the material models in the Eurocodes. In EN 1991-1-2 appendix A, a method to calculate parametric fire curves is presented, the method results in temperature-time curves and is known as the Eurocode model. This method considers the final room geometry and fire load, it also contains a cooling phase unlike the standard fire curve. Therefore, the Eurocode model is considered to be better at describing real fires. Compartment and room fires based on geometries from real apartments, will be calculated with the Eurocode method in order to compare the temperature-time curves against the exposure of the standard fire curve. The project started with a study of former literature to give a deeper understanding in the current subject. After that, real apartment drawings were collected to represent real apartments. The drawings were then used as input for the calculation method in EN 1991-1-2 appendix A. To calculate in a more effective way an Excel spread sheet was created for the calculation method according to the Eurcode model, which later has been used for all calculations. Four different scenarios were created, including two different thermal inertia and two different opening factors for each thermal inertia. The reason why was that it seemed to be interesting to examine in what extent these parameters affect a fire. It resulted in that scenario 3, the scenario with a lower thermal inertia and a higher opening factor, were the scenario with the fastest growing fire and with the highest temperatures. In comparison with the standard fire curve, scenario 3 had a majority of fires that exceeded the standard fire curve’s temperatures until the cooling phase begun. Scenario 2 which had a higher thermal inertia and a lower opening factor resulted in the opposite, that is a fire burning during a longer time with overall lower temperatures. In comparison with the standard fire curve scenario 2 had a majority of fires with lower exposure of temperature than the standard fire curve, during the entire time of fire. The opening factor controls which amount of oxygen that flows in to the fire compartment, an increase of the amount of oxygen leads to a more intensive fire. The thermal inertia controls how slowly something gets warmed up, a lower thermal inertia means that the fire compartment warms up faster and resulting in higher temperatures as less energy is absorbed by the walls. The calculated compartment and room fires temperature-time curves was in a better agreement with the standard fire curve than expected. Given that the floor and roof is concrete, the walls is gypsum and together with the assumption that the fire load defined by Boverket is correct, is the conclusion that the standard fire works well in most cases. However, the fire growth rate is lower for the standard fire than for some calculated cases but have a temperature at 60 minutes that exceeds most of the calculated cases at the same time. The fire resistance tests can still develop since a big amount of the calculated temperature-time curves exceeded the standard fire curve in periods of time over 30 minutes, something that could affect the fire protection requirements. But the majority of the calculated fires had an exposure of temperature under the standard fire curve. Therefore, the standard fire and the requirements can sometimes be considered oversized based on the work that been done.

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Forest fires cause a significant amount of damage and destruction each year. Optimally dispatching resources reduces the amount of damage a forest fire can cause. Models predict the fire spread to provide the data required to optimally dispatch resources. However, the models are only as accurate as the data used to build them. Satellites are one valuable tool in the collection of data for the forest fire models. Satellites provide data on the types of vegetation, the wind speed and direction, the soil moisture content, etc. The current operating paradigm is to passively collect data when possible. However, images from directly overhead provide better resolution and are easier to process. Maneuvering a constellation of satellites to fly directly over the forest fire provides higher quality data than is achieved with the current operating paradigm. Before launch, the location of the forest fire is unknown. Therefore, it is impossible to optimize the initial orbits for the satellites. Instead, the expected cost of maneuvering to observe the forest fire determines the optimal initial orbits. A two-stage stochastic programming approach is well suited for this class of problem where initial decisions are made with an uncertain future and then subsequent decisions are made once a scenario is realized. A repeat ground track orbit provides a non-maneuvering, natural solution providing a daily flyover of the forest fire. However, additional maneuvers provide a second daily flyover of the forest fire. The additional maneuvering comes at a significant cost in terms of additional fuel, but provides more data collection opportunities. After data are collected, ground stations receive the data for processing. Optimally selecting the ground station locations reduce the number of built ground stations and reduces the data fusion issues. However, the location of the forest fire alters the optimal ground station sites. A two-stage stochastic programming approach optimizes the selection of ground stations to maximize the expected amount of data downloaded from a satellite. The approaches of selecting initial orbits and ground station locations including uncertainty will provide a robust system to reduce the amount of damage caused by forest fires.

Every year wildfires threaten or destroy ecological habitats, man-made infrastructure and people’s lives. Additionally millions of dollars are spent each year trying to prevent and control these fires. Ideally if a wildfire can be detected before it rages out of control it can be extinguished and avoid large scale devastation. Traditional manned fire lookout towers are neither cost effective nor particularly efficient at detecting wildfire. It is proposed that temporal filtering can be used to isolate the signals created at the beginnings of potential wildfires. Temporal filtering can remove any background image and any periodic signals created by the camera movement. Once typical signals are analyzed, digital filters can be designed to pass fire signals while blocking the unwanted signals. The temporal filter passes only fire signals and signals generated by moving objects. These objects can be distinguished from each other by analyzing the objects mid and long wave energy profile. This algorithm is tested on 17 data sources and its results analyzed.

Vätgas är en energibärare som kan vara en av pusselbitarna i omställningen till en mer klimatneutral värld. Infrastrukturen byggs ut, industrin växer och vätgasfordon blir vanligare. Vätgas är ett ämne med de bra egenskaperna att det kan lagra kemisk energi och från förnybar el tillverkas med elektrolys, men det har också den riskabla egenskapen att det är mycket brandfarligt. Vid läckage av vätgas finns risken att en jetflamma med höga temperaturer uppstår vilket påverkar omgivningen där det sker. Standarder för jetbrandtester är idag baserade på tester med propan, men då vätgas har andra egenskaper behövs ökad kunskap för att minska riskerna vid olyckor. Studien syftar till att via litteraturstudier samla information om storskaliga jetbrandtester, vilken utrustning som används, hur material påverkas av jetflammor och vilka standarder som finns för jetflammor och jetbrandtester. Ett av syftena är också att med intervjustudie ta reda på hur räddningstjänsten i Luleå ser på utvecklingen av vätgasinfrastruktur och om de har några rutiner för olyckor med vätgas. Det finns en vision vid Luleå tekniska universitet att det i framtiden ska finnas en anläggning för att utföra jetbrandtester av vätgas och andra bränslen i Luleå. Studien syftar därför också till att via intervju ta reda på om räddningstjänsten i Luleå skulle ha någon användning för en sådan anläggning. Jetbrandtester kan enligt standarden SS-ISO 22899-1:2021 utföras i mindre skala med propan som bränsle och ändå ge liknande resultat som vid storskaliga jetbrandtester med naturgas. Jetbrandtestet utförs för att testa brandmotstånd genom integritet (E) och isolerande förmåga (I) för passiva brandskyddsmaterial som används till rör, paneler, konstruktionsstål och rör- och kabelgenomföringar. Testerna utförs enligt standarden med utrustning såsom munstycke, åter-cirkuleringskammare, skyddskammare, med mera. Enligt standarden SS-ISO 22899-1:2021 träffas testobjektet vid ett jetbrandtest med en jetflamma av propan på 1 meters avstånd. Det korta avståndet medför att propanet inte fullt hinner förbrännas vilket skapar temperaturskillnader på testobjektets yta när det träffas av flamman. Det bildas en ”kall” och en ”varm” zon på ytan där den ”kalla” zonen är den punkt som i direkt kontakt med jetflamman utsätts för mekanisk kraft i form av erosion. För vätgas hinner flamman stabilisera sig på en meters avstånd vilket gör att testobjektet träffas av en fullt utvecklad flamma och därför både utsätts för termiska laster i form av en enhetlig ”varm” zon och mekaniska laster i form av erosion. Denna skillnad kan göra att passiva brandskyddsmaterial vid jetflammor av vätgas inte klarar av att upprätthålla det krav på brandmotstånd som ställs. Detta är främst aktuellt att undersöka för reaktiva passiva brandskyddamaterial då de är mer känsliga för erosion än icke-reaktiva passiva brandskyddsmaterial. Om så är fallet att passiva brandskyddsmaterial inte klarar av att motstå jetflammor av vätgas lika bra som för propan kanske en standard för jetbrandtester med vätgas skulle behöva tas fram. Det kan vid intervjun med PärJohan Fredrickson som är sektionschef för myndighetsutövningen vid Luleå räddningstjänst konstateras att de verkar vara väl informerade om utvecklingen av vätgasinfrastrukturen och att de har varit delaktiga i vätgasfrågor sedan några år tillbaka. De har samarbeten med andra räddningstjänster och de försöker tidigt vara med i dialogen när nya processer och verksamheter utvecklas. De har i dagsläget inte några operativa övningar med jetflammor av vätgas men de arbetar förebyggande genom att ta fram insatsplaner tillsammans med de industriella verksamheter som hanterar vätgas. De kan från ett förebyggande perspektiv se hur räddningstjänsten kanske skulle kunna ha användning av en anläggning för att genomföra jetbrandtester med vätgas. Men om det finns något operativt behov behöver vidare utredas med personal på räddningstjänsten som arbetar inom de operativa resurserna. / Hydrogen is an energy-carrier that can be a piece in the change for a climate neutral world. The infrastructure and industry expand, and hydrogen vehicles becomes more common. Some good characteristics with hydrogen are that it from renewable energy can be produced through electrolysis and store chemical energy, but it also has the risky characteristic that its very flammable. If hydrogen gas would leak from a container there is the risk of a jet flame with high temperatures that can affect the surroundings. Today’s standards for jet fire testing are based on propane gas, but because hydrogen has so many different characteristics there might be a need for more knowledge to prevent risks and accidents. Through a literature study this report aims to gather information about large scale jet fire testing, what equipment that is used, how materials react to jet flames, and what standards that are current for jet fire testing and jet flames. A purpose is to through an interview-study figure out how the rescue service in Luleå sees on the development in hydrogen infrastructure and if they have any routines for accidents with hydrogen. Luleå University of Technology has a vision to in the future have a facility in Luleå where they can perform jet fire testing with hydrogen and other flammable fuels. One purpose of the study is therefore to interview the rescue service in Luleå to investigate if they would have any interest in such facility and what use they could have of it. According to the standard SS-ISO 22899-1:2021, jet fire tests with propane gas can be performed in a smaller scale and still give similar results as for large scale jet fire tests with natural gas. The jet fire test is performed to determine the fire resistance regarding integrity (E) and isolating capacity (I) for passive fire protection materials that are used for pipes, panels, structural steelwork, and pipe penetration seals. The gear that is used for the tests are a nozzle, flame re-circulation chamber, protective chamber etc. A propane flame hits the object of testing from 1 meter according to the standard. Because of the short distance, the propane flame does not reach full combustion which leads to a temperature difference on the object of testing that is encountered with the jet flame. A “cold” and “hot” zone is therefore created at the surface where the “cold” zone appears at the center core of the jet flame. At this core, the object of testing is exposed to a higher mechanical force in terms of erosion than other parts of the object. For hydrogen the jet flame stabilizes in 1 meter which changes how the flame affects the object of testing. The object is instead hit by a fully combusted jet flame that exposes it to high thermal load with a uniform “hot” zone and mechanical load of erosion. That difference could change how passive fire protection (PFP) materials are able to resist jet flames with hydrogen as the tests for PFP materials are done with propane. This would mainly be topical for reactive PFP materials as they are more sensitive to erosion than non-reactive PFP materials and a standard for jet fire tests with hydrogen may become relevant if PFP materials fail to maintain the requirements that are set for propane. The interview with section manager PärJohan Fredrickson that works at Luleå rescue service shows that Luleå rescue service seems to be well informed about the development of hydrogen infrastructure. Since a few years back they have been involved with questions relating to hydrogen, they have collaborations with other rescue services around the country and they try to get involved as early as possible when new processes and operations are formed. They do not seem to do any exercises where they train for jet fire accidents with hydrogen involved but they are working to prevent accidents with hydrogen. Action plans has been and are being developed together with the operations that are handling the hydrogen. The rescue service could from a preventive perspective have a use of a facility for jet fire testing with hydrogen. But it must be further investigated if there is an operative need to use such a facility.

Impelled by the increase in the number of tunnel fires in the last decade alone, wide spread attention has been drawn towards tunnel fire safety studies. Many of these fires occurred in road and railway tunnels involving vehicles and trains. These fire incidents have claimed lives, caused structural damages to the tunnel infrastructure and even economic losses to the government, businesses and communities concerned. When there is a fire in a tunnel, the temperature inside the tunnel increases rapidly to magnitudes as high as 1500°C. At such high temperatures costly damages to the tunnel structure is inevitable. Having an understanding of the detrimental effects of such high temperatures is essential and valuable when carrying out preliminary assessment of the type and extent of damage in the tunnel. This would in turn provide useful information in determining the appropriate remedial measures required to make the tunnel safe and usable again in the aftermath of a tunnel fire. In most tunnel fire safety studies, the focus has been on the behaviour of concrete, since of course concrete is one of the major support elements in tunnels. However, in several cases, such as in Scandinavia for example, where the rock mass is competent enough to support itself only a thin layer of shotcrete is used usually on tunnel walls. In such cases the rock will be fully exposed to heat in an instance of fire. In this case, whether it is prevention or maintenance of the tunnel, it would require knowledge on the effect of elevated heat on the rock mass. Hence, it is line with this thinking that a study was initiated by the Swedish Transport Administration (Trafikverket), Kärnbränslehantering AB, SKB and Vattenfall to study the effect of heat on the physical and mechanical properties of some common rock types, and hence the focus of this thesis. This thesis presents the results of a series of laboratory studies which was carried out to investigate the effect of heat on the physical and mechanical properties of selected rock types, namely; diabase, granite and quartzitic schist. Samples from these rock types were heat treated at temperature levels of 400°C, 750°C and 1100°C, before investigating their mechanical and physical properties through mechanical testing and microscopic investigations of thin sections. Because the effect of heat on rock can be affected by the heating rate and exposure time, the test were conducted under controlled conditions in order to avoid significant variation in the results. The results clearly show that the rock types behave differently at different temperature levels, which tend to depend on the mineral composition and micro cracks distribution. As the temperature increases the rock forming minerals undergo changes in their chemical structure thus causing them to alter from the original phase they had existed in. With these phase changes different reactions take place such as re-crystallization, the loss of crystal bound water, thermal expansion and micro cracking of mineral grains as well as the development of voids. These microscopic changes were manifested in the macro-scale by the variations observed in the behaviour of strength and stiffness of the samples in the mechanical tests.

Ecosystem disturbances are a significant and ongoing threat to wildlife, caused by both natural environmental changes and human impacts. These disturbances can have a range of impacts, but one of the most crucial is on the wildlife habitat. In tropical forests, one such disturbance that is occurring at an alarming rate is peat fires. Peatfires impact the forest structure and fragmentation, which in turn directly relate to the wildlife habitat, ultimately threatening the population and even risking extinction for certain species. Of particular concern is the population of orangutans in Indonesia, which is at risk due to the impact of peat fires. This research used an agent-based modelling approach to explore the impact of ecosystem disturbances on wildlife habitat. The focus was on the orangutan population in tropical forests affected by peat fires. A systematic review of agent-based models revealed a shift towards a more mechanistic representation of entities in wildlife response to disturbances. However, fire disturbances and primate species such as orangutans still have a limited number of models. To address this gap, two agent-based models are presented: PeatFire, a model of the ignition and spread of tropical peatfire, validated using data from a fire pattern in South Sumatra; and the BORNEO model, which simulates the movement behaviour of orangutans in a disturbed forest using real tree inventory data and orangutan tracking data from the Sebangau forest in Central Kalimantan. The models were calibrated and validated using state-of-the-art methods and high-performance computing. The study demonstrates the ability of ABM to tackle complex research problems in various fields, including wildlife response to disturbances. The models developed in this study are important examples of the shift towards a more mechanistic representation of agents in ABM, and contribute to advancing the field in this direction. The research offers insights into the impact of ecosystem disturbances on wildlife habitat and highlights the potential of ABM in addressing these issues.

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