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  • 101.
    Ingason, Haukur
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Gehandler, Jonatan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Metoder för att testa dukar och membran i tunnlar och bergrum2018Rapport (Annet vitenskapelig)
    Abstract [en]

    Tunnel and rock lining systems are used for drainage and icing protection. These systems can consist of any combination of concrete, metal, plastic or textile. The report summaries the available methods, both for testing and for installation. The large variation in both systems and test methods often make it difficult for constructors or designer to understand the importance of different methods. The report gives indication of what type of linings exists and how to ensure the fire safety of such systems. Fire safety properties can be verified in three different ways: #1 Full systems can be tested in full scale fire tests, #2 a section of the system can be tested in standardized furnace tests, or #3 plastic and/or textile membrane can be tested with regards to requirements on fire spread. It is suggested to require that a fire should not be able to propagate in the system. This can be verified with #3 above requiring class B, C or D according to EN 13501-1. If the lining system offers structural fire protection, it can be verified suing #2 above.

    Fulltekst (pdf)
    fulltext
  • 102.
    Ingason, Haukur
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Large scale tunnel fire tests with different types of large droplet fixed fire fighting systems2019Inngår i: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 107, s. 29-43Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The paper presented the main results of large-scale fire tests with different types of fixed firefighting systems (FFFS) conducted in the Runehamar tunnel in June 2016. The background to the tests, the performance of the different systems, and conclusions regarding the efficiency of the systems were presented. The fire load consisted of 420 standardised wooden pallets and a target of 21 wooden pallets. Five of the tests were carried out with a 30 m long deluge zone delivering varying water densities using three different types of side-wall nozzles with an interval distance of 5 m. One test with 93 °C glass-bulb automatic sprinklers in the same zone was also conducted. In the five deluge tests, the detection system was simulated using thermocouples in the tunnel ceiling. The alarm was registered when the ceiling gas temperature reached 141 °C, and the system was activated manually after a delay of 4 min. The protection goal of the system was to prevent fire spread to a target positioned 5 m from the rear of the main fuel area, and to ensure that the fire did not exceed 30 MW in size. The system setups tested were found to meet these goals.

  • 103.
    Ingason, Haukur
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Spilled liquid fires in tunnels2017Inngår i: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 91, s. 399-406Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The study focuses on release of liquids inside tunnels from tankers containing dangerous good. Experiments and analysis from large scale tests are presented. The tests include different leakage rates, leakage type, liquids, spillage sizes on sloping surfaces and heat release rates. Models for estimation of leakage rates, spillage sizes and heat release rates for different scenarios are presented. The results are important to use in the design of active fire protections systems in tunnels including ventilation, fixed fire-fighting and drainage systems.

  • 104.
    Ivanov, O. L.
    et al.
    Lund University, Sweden.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Byggteknik.
    Santandrea, Fabio
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Stripple, H.
    IVL Swedish Environmental Institute, Sweden.
    Prolca—treatment of uncertainty in infrastructure LCA2019Inngår i: Life-Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision - Proceedings of the 6th International Symposium on Life-Cycle Civil Engineering, IALCCE 2018, CRC Press/Balkema , 2019, s. 2923-2930Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The construction, operation and maintenance of transportation infrastructure require energy and materials which impact the environment. Large infrastructure projects thus use resources intensively and leave a significant environmental footprint. To demonstrate and support the sustainability of such large-scale projects, life cycle assessment (LCA) has become a common tool to evaluate environmental impacts in all stages of infrastructure life cycle, from raw material production through end-of-life management. However, the various phases of the assessment are all associated with uncertainties. If decisions are made without consideration of these uncertainties, they might be misleading and suboptimal. In this paper, results are presentedwhere variations associated with different parameters and tools for life cycle assessment have been considered using probabilistic methods. A categorization of common uncertainties in LCA is also included. The most influential parameters can be identified with sensitivity analysis methods, since for LCA with a large number of parameters it may be unreasonable to incorporate all in a probabilistic simulation. For a limited amount of influential variables, Monte Carlo simulation has been used to assess the effects of uncertainties on the results.A bridge has been used as a case study to find important aspects in infrastructure LCA. The results indicate that if the most influential parameters are considered as random variables, it is possible to estimate the uncertainty and increase the validity of the life cycle assessment.

  • 105.
    Jacobsson, Lars
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Storskaliga labförsök för ökad förståelse av spjälkningsprocessen2017Inngår i: Svenska Bergmekanikgruppens höstseminarium, 29 november 2017 på Äspölaboratoriet: Bergmekanisk forskning vid Äspölaboratoriet – historiska framsteg och framtida utmaningar, 2017Konferansepaper (Annet vitenskapelig)
  • 106.
    Jacobsson, Lars
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Appelquist, Karin
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Lindqvist, Jan Erik
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Åkesson, Urban
    Swedish Transport Administration, Sweden.
    Spalling initiation experimentson large hard rock cores2018Rapport (Fagfellevurdert)
    Abstract [en]

    A new type of laboratory test method to determine spalling resistance in a situation as in large boreholes in hard rock has been demonstrated. Uniaxial compression tests on large cores with notches were conducted on Äspö diorite from Äspö HRL. Spalling was localized to the notches where the local stress was highest. The crack initiation, crack coalescence and crack damage stresses representing various fracture stages were identified by using acoustic emission monitoring with source localization. The actual stress levels were obtained from the axial forces at which the various fracture stages were identified via FE-calculations representing the actual specimen geometry and loading. The results were compared with uniaxial compression tests carried out on cores with standard size on the same rock type also from Äspö HRL.

    The results showed that spalling chips were formed similar to those found in field which indicates that the test is representing a realistic behaviour. However, the results show that the various fracture stress levels found in the tests are higher than the spalling strength found in the field and in the test of small cores. The higher stress levels could be caused by a number of reasons described in the report.

    A post characterization of the fractures was carried out on slabs that were cut out from the specimens containing the notch areas. The occurrence of microcracks and how they have propagated through the different minerals and the location in relation to the notches, minerals and grain boundaries were investigated. The patterns of the major fractures and the secondary fractures were analysed. The majority seem to be extension fractures, but shearing could also be verified. The results from the microscopy analysis provide invaluable information of the spalling process at all stages.

  • 107.
    Jacobsson, Lars
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Kjell, Gunnar
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Measurement of p- and s-wave velocity in material using ultrasonics2017Rapport (Annet vitenskapelig)
    Abstract [en]

    The velocities of propagating elastic waves can be used to determine the amount of damage in form of induced microcracks in rock materials and other materials. An increasing number of microcracks yields lower propagation velocities. To assess the damage, e.g. around tunnels caused by the excavation, is of interest since the damage affects the material properties, such as mechanical and thermal properties and permeability.

    A new ultrasonic testing system ULT-100 from GCTS (Geotechnical Consulting and Testing Systems), aimed for measurement of p- and s-wave velocities, was evaluated. Reference cylindrical specimens in aluminium with different sizes were manufactured and a series of tests were conducted in order to find suitable wave arrival picking methods and to determine equipment specific constants which are needed to be determined. The procedure to do this was according to an ASTM standard.

    Expanded measurement uncertainties for the wave velocity measurements were calculated according to Guide to the Expression of Uncertainty in Measurement (GUM).

    Equipment such as sensor holders and fixtures were manufactured in order to be able to conduct repeatable measurement on specimens. One test rig was made to carry out tests on nearly unloaded specimens in one direction and another was made for tests on axially loaded cylinders in a standard load frame with measurements in the axial plus two lateral directions.

    A Round Robin test was carried out on the three different types of testing equipment, one at SP, one at Swedish Cement and Concrete Research Institute (CBI), and one at Finnish Geological Survey (GTK) in Finland to evaluate the measurement results on p-wave velocity measurements. The results of the measurements were mainly in line with the calculated measurement uncertainties.

    The report is directed to persons working with wave velocity measurements using ultrasonics with particular interest of quality assurance of the measurements, which includes calibration, validation and uncertainty estimation.

    Fulltekst (pdf)
    fulltext
  • 108.
    Jacobsson, Lars
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Kjell, Gunnar
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Brander, Linus
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Kiuru, Risto
    Pöyry Finland Oy, Finland.
    EDZ Study Area in ONK-TKU-3620; Determination of Seismic Wave Velocities at Six Load Levels, Pethrophysical and Rock Mechanical Properties of Drill Core Specimens2019Rapport (Annet vitenskapelig)
    Abstract [en]

    Laboratory experiments on specimens from the excavation damaged zone area in the ONK-TKU-3620 were conducted. The experiments comprised density and porosity measurements, P- and S-wave velocity measurements at unloaded condition in one direction and at uniaxial compression in three orthogonal directions, indirect tensile tests and uniaxial compression tests on cylindrical specimens of veined gneiss (VGN) and granitic pegmatoid (PGR). All tests were conducted on saline (formation) water saturated specimens.

    The density and porosity measurements revealed a dependence of the saturation procedure between the one used at the Finnish Geological Survey and the one recommended by ISRM. It should be noted that the applied procedure deviated slightly from the procedure defined by the ISRM. The deviation decreased after saturating the specimens again by long-term immersion in water (5 weeks or more) and re-measuring the specimens in water saturated state. Increased porosity compared to the other tested specimens could be observed in one specimen that had a visually observable sealed joint. Some other specimens had a slightly increased deviating porosity.

    The wave velocities measured under loading in three directions showed anisotropy in almost all specimens. The anisotropy was expected in the structurally anisotropic VGN specimens. Anisotropy was also observed in the structurally isotropic PGR specimens. The anisotropy in this case may be either a weak foliation or oriented microfractures. The anisotropic wave velocity data match measured strains. The wave velocities for the VGN also match the response that is expected at transverse isotropy which is a suitable constitutive model assumption for the VGN.

  • 109.
    Jacobsson, Lars
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Kjell, Gunnar
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Kiuru, Risto
    Aalto University, Finland.
    Suikkanen, Johannes
    Posiva OY, Finland.
    Wave velocity measurements in three directions on axially loaded water-saturated granite and gneiss core specimens2019Inngår i: Proceedings of the 14th International congress on Rock Mechanics ans Rock Engineering (ISRM 2019), Foz do Iguassu, Brazil, 13-18 September 2019: Rock Mechanics for Natural Resources and Infrastructure Development / [ed] Sergio A.B. da Fontoura, Ricardo José Rocca, José Félix Pavón Mendoza, Leiden, The Netherlands: CRC Press, 2019, s. 1638-1645Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The density, porosity and mechanical properties from uniaxial compression and Brazilian tests along with measurements of the P- and S-wave velocities in axial and two lateral directions at unloaded state and at increasing axial load were conducted on cylindrical cores of veined gneiss and granitic pegmatoid. The specimens were sampled close to a tunnel wall (0.1– 1.7 m depth) with the aim to find if there is an increasing amount of microcracks due to the excavation in a zone near the surface. Evidence of microcracks was found via the mechanical tests and the wave velocity measurements, due to increased mechanical stiffness and increasing wave velocities at loading. Anisotropy in in the gneiss specimens and also in the granitic pegmatoid was detected and measured via strain and wave velocity measurements. No clear evidence was found of increased amount of microcracks closer to the tunnel wall.

  • 110.
    Jacobsson, Lars
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Lindqvist, Jan Erik
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Laboratory investigation of crack initiation on hourglass-shaped granite specimens2018Inngår i: Geomechanics and Geodynamics of Rock Masses, Volume 1: Proceedings of the 2018 European Rock Mechanics Symposuim / [ed] Vladimir Litvinenko, London: CRC Press, 2018, s. 633-638Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Laboratory experiments on axially compressed hourglass-shaped specimens of medium to coarse grained granite specimens were conducted. A tangential stress is generated in the circular notches which is intended to initiate surface spalling similar to what can be seen at circular openings in a rock mass. Specimens of three different sizes were tested with notch radii 98.4, 225 and 375 mm, which are equivalent to a hole diameter of 197, 450 and 750 mm. The spalling initiation and progress in the notches were monitored by acoustic emission and digital correlation measurements. From the acoustic emission measurements it could be seen that the tangential stress at spalling initiation decreased with increasing notch radius. Results from digital image correlation show how the surfaces in local zones in the notch were pushed outwards due to subsurface cracking parallel to the notch surface. Analyses of thin sections and polished slabs taken in the notch area showed that the cracking depth increased with increasing notch radius.

  • 111.
    Jacobsson, Lars
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Lindqvist, Jan Erik
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Laboratory investigation of stress gradient effect at spalling experiments on granite2015Inngår i: The 13th International Congress of Rock Mechanics: ISRM Congress 2015, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A series of laboratory tests were conducted to study stress-induced spalling on medium to coarse-grained granite specimens. The specimens made from cylinders had two manufactured notches on opposite sides aimed to represent the tangential loading around a circular opening. Specimens of three different sizes were tested with notch radii, 98.5, 225 and 375 mm, representing 197, 450 and 750 mm diameter holes, to study the effect of notch radius on the spalling initiation stress. The cracking was monitored by acoustic emission sampling. The fracture patterns were investigated visually on polished slabs and by microscopy on thin sections. The crack analysis describes how the cracks propagate in relation to the grain structure in the rock and to the macroscopic stress field.

  • 112.
    Jacobsson, Lars
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Sandström, Johan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Brander, Linus
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Wedge splitting tests on granite and gneiss specimens2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The conditions for initial tensile cracking around a rounded blunt and a sharp notch and subsequent propagation were investigated by means of wedge splitting tests on structurally isotropic granite. In addition, the crack initiation and propagation on anisotropic gneiss specimens with a blunt notch were investigated in two different material directions. The wedge splitting test specimens which has a straight notch is normally used to determine mode I fracture properties for concrete but not for rock materials. The use of a straight notch in the specimens instead of a chevron type of notch, which is commonly used for fracture mechanics tests, was found to be well suited for the actual type of investigation. 

    The development of fractures from the notch into the specimens was monitored by measuring the deformation field on the specimen surface by digital image correlation (DIC) and by the crack mouth opening displacement. The fracture patterns were different in the granite and the gneiss. The DIC illustratively showed how cracks branched along the main crack path in the granite whereas no branching occurred in the gneiss material. This could also be verified by studying thin sections taken along the fracture path. It was seen that the granite behaved more ductile than the gneiss. 

    A finite element model of the wedge splitting test was made where the crack propagation was modelled using a cohesive-zone model and calibrated using the results from the experiments. The fracture energies were computed and it was found that the energies were about 50-100 percent higher in the granite than in the gneiss. The tensile stress cracking initiation in granite for the blunt and the sharp notch was slightly different. The gneiss specimens were all with a blunt notch and a comparison of the two notch types could not be made in this case.

  • 113.
    Jacobsson, Lars
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Sjöström, Johan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Forsmark – Laboratory tests for investigation of the influence of rock type, oxidation, and other factors in borehole breakouts. Boreholes KFM01A, KFM04A, KFM05A and KFM24. Thermal properties by TPS method and uniaxial compression and indirect tensile strength tests of intact rock2019Rapport (Annet vitenskapelig)
    Abstract [en]

    The density, thermal and mechanical properties were determined on water saturated specimens from boreholes KFM01A, KFM04A, KFM05A and KFM24 in the Forsmark site investigation area. The tests have been concentrated to sections where borehole breakouts have been observed. The rock types in the selected sections were amphibolite (102017), granite to granodiorite (101057) and skarn (108018).

    All specimens had a more or less foliated rock structure. The cores were sampled from a depth ranging between 308–929 m.

    The specimens were water saturated using tap water and all subsequent measurements were conducted at this moisture condition. The density was determined on 41 specimens followed by measuring the thermal properties of 20 pairs of specimens. The thermal conductivity and diffusivity were measured and the volumetric heat capacity was calculated from the thermal conductivity and diffusivity. The testing ended with 35 indirect tensile tests yielding the indirect tensile strength and three uniaxial compression tests including the post-peak response yielded the Young’s modulus, Poisson ratio and the uniaxial compressive strength.

    Three specimens aimed for the indirect tensile tests had a major crack and fell apart after measuring the density and the mechanical properties were not tested.

    Some variation of rock material along the short cores could be seen, which is reflected in the measured data. The density at a water saturated condition was 2 640–2 814 kg/m3 for granite to granodiorite, 2 768–3 033 kg/m3 for amphibolite and 2 787–2 920 kg/m3 for skarn.

    Thermal properties were measured at ambient temperature (22 °C) and under water saturated conditions. The determination of the thermal properties is based on a direct measurement method, the so called “Transient Plane Source Method” (TPS).

    Thermal conductivity and thermal diffusivity at 22 °C were in the range of 1.6–3.5 W/(m, K) and 0.9–1.9 mm2/s, respectively. The volumetric heat capacity, which was calculated from the thermal conductivity and diffusivity, ranged between 1.6 and 2.6 MJ/(m3, K). Variations are most likely due to both depth and variations in rock type.

    The indirect tensile tests were conducted such that every second specimen was tested with the diametrical compression along and every second across the foliation planes, with higher values for the indirect tensile strength on the specimens with loading across the foliation. The ratio between the strength measured on specimens with loading across over along the foliation was up to 1.6 for granodiorite and possible higher for the amphibolite. The strength variation in the amphibolite was large. The indirect tensile strength was 8.07–14.5 MPa for the granite to granodiorite, 1.18–16.2 MPa for amphibolite and 4.49–8.51 MPa for skarn.

    Two of the uniaxial compression test specimens of amphibolite got a diagonal failure and the third had a spalling failure. The maximum axial compressive stress was 61.5 and 68.5 MPa for the specimens with a diagonal failure and 238.7 MPa for the specimen with a spalling failure. The Young’s modulus for the same specimens was 61.6 and 57.5 GPa, respectively 91.0 GPa and the Poisson ratio 0.288 and 0.407, respectively 0.375.

  • 114.
    Johannesson, Pär
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Podgórski, Krzysztof
    Lunds University, Sweden.
    Rychlik, Igor
    Chalmers University of Technology, Sweden.
    Laplace distribution models for road topography and roughness2017Inngår i: International Journal of Vehicle Performance, ISSN 17453194, Vol. 3, nr 3, s. 224-258Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Gaussian models are frequently used for road elevations. However, these models are often only valid for short sections of the road. Here we present a comprehensive approach to describe various aspects of road surface/elevation by using extensions of Gaussian models arising from random gamma distributed variances. These random variances result in the Laplace distribution and thus we refer to the so defined models as Laplace models. The approach is shown to perform well in modelling road topography, road roughness and multi-valued responses of forces and bending moments containing transients. The different Laplace models are presented together with numerical examples and Matlab code for simulation.

  • 115.
    Johansson, Nils
    et al.
    Lunds University, Sweden.
    Pelo, Christian
    Ramboll, Sweden.
    Anderson, Johan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    McNamee, Robert
    Brandskyddslaget, Sweden.
    CFD-beräkningar vid brandteknisk dimensionering - En Round Robin studie2019Rapport (Annet vitenskapelig)
    Abstract [sv]

    I studien utförde nio deltagande aktörer samma beräkningsuppgifter utan att veta vad de andra kommit fram till. Resultatsammanställningen visar en relativt stor spridning som till största delen kan förklaras med att deltagarna gör olika ingenjörsmässiga val. Läs den och fundera på vilka ingenjörsmässiga val du gör i vardagen.

    Fulltekst (pdf)
    fulltext
  • 116.
    Johansson, Roine
    et al.
    Mid Sweden University, Sweden.
    Danielsson, Erna
    Mid Sweden University, Sweden.
    Kvarnlöf, Linda
    Mid Sweden University, Sweden.
    Eriksson, Kerstin
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Karlsson, Robin
    Mid Sweden University, Sweden.
    At the external boundary of a disaster response operation: The dynamics of volunteer inclusion2018Inngår i: Journal of Contingencies and Crisis Management, ISSN 0966-0879, E-ISSN 1468-5973, Vol. 26, nr 4, s. 519-529Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In the present article, practices of inclusion of different types of volunteers in the response to a large-scale forest fire in Sweden are studied. Semi-structured interviews were conducted with three types of voluntary actors. The volunteers were organized to different degrees, from members of organizations and participants in emergent groups to organizationally unaffiliated individuals. Organized volunteers were the most easily included, particularly if they were members of voluntary emergency organizations. It was difficult for volunteers lacking relevant organizational affiliation to be included. Disaster response operations are dynamic, conditions change over time, and tensions between different modes, degrees, and levels of inclusion may arise. However, irrespective of changing conditions, practices of inclusion of highly organized volunteers work best. © 2018 The Authors Journal of Contingencies and Crisis Management Published by John Wiley & Sons Ltd

  • 117.
    Just, Alar
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Brandon, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Fire Stops in Buildings2017Rapport (Annet vitenskapelig)
    Abstract [en]

    In a statistical study performed by the London fire brigade in the Real Fires Database it was found that out of 30 086 fires occurring between 2009 and 2011, fire spread beyond the floor of origin through gaps or voids occurred in 92 cases. This illustrates that the phenomenon is relatively rare. However, it can lead to severe property damage. Fires can spread invisibly within cavities of the structure, which has led to problems concerning the extinguishment of the fire. Cavity barriers function is to stop the fire spread through cavities. However, these cavity barriers have not always been effective.

    This report is the result of a study that aimed to:

    1. Develop a robust testing method for cavity barriers for cavities with combustible materials within walls, floors and other elements in buildings.

    2. Provide guidelines for the materials, installation, positioning, detailing and location of the cavity barriers.

    Additionally, a preliminary study is performed to assess some extinguishing strategies.

    Based on a study of characteristics of cavity fires, current standard fire tests for cavity barriers were revised for the use in cavities with combustible materials. From tests following the revised methodology, guidelines regarding the dimensions, installation and fire stopping design are provided.

    Fulltekst (pdf)
    fulltext
  • 118.
    Just, Alar
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety. Tallinn University of Technology, Estonia.
    Brandon, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Mäger, K. N.
    Tallinn University of Technology, Estonia.
    Pukk, R.
    Estonian Academy of Security Sciences, Estonia.
    Sjöström, Johan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Kahl, Fredrik
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    CLT compartment fire test2018Inngår i: WCTE 2018 - World Conference on Timber Engineering, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    New high-rise timber buildings are planned to be built in the near future all around the world. The fire protection concepts are not always considering natural fire scenarios. As timber is a combustible material, it can contribute to the fire within and outside of the fire compartment. For buildings with cross-laminated timber (CLT) elements the possible fall-off of lamellas should be considered because of the risk for second flashover, which can lead to a continuous fire. However, in case fire service interference or sprinkler activation is absent or inefficient, it may be necessary to design a building so that it leads to a decaying fire. Additionally, it is important to limit fire spread to neighbouring compartments. This paper discusses a compartment test of a two-story building made of CLT performed in Estonia to study delamination behaviour and consequences in compartments with realistic ventilation conditions. State-of-the art solutions to limit fire spread from the first floor into the second floor were applied. This involved robust design of connections, penetrations through the compartment boundary and the façade. The paper provides a description and analysis of the test.

  • 119.
    Karlsson, Stefan
    et al.
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Byggteknik.
    Järn, Mikael
    RISE - Research Institutes of Sweden, Biovetenskap och material, Kemi och material.
    Welinder, Jan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Elektronik.
    Andersson, Anne
    RISE - Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Liinanki, Matilda
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Byggteknik.
    Försth, Michael
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Transparent intelligens för en bättre värld - en sammanfattning av fyra år med TIME2017Inngår i: GLAS, nr 2, s. 58-59Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
  • 120.
    Karlsson, Stefan
    et al.
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Byggteknik.
    Österlund, Lars
    Uppsala university, Sweden.
    Niklasson, Gunnar
    Uppsala university, Sweden.
    Granqvist, Claes-Göran
    Uppsala university, Sweden.
    Järn, Mikael
    RISE - Research Institutes of Sweden, Biovetenskap och material, Yta, process och formulering.
    Eriksson, Jerry
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Byggteknik.
    Welinder, Jan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Elektronik.
    Försth, Michael
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety. Luleå tekniska universitet, Sweden.
    Ludvigsson, Mikael
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Byggteknik.
    “Transparent Intelligence” for Sustainable Development2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Transparent materials are essential in everyone’s life. They enable daylight to reach the interior of buildings, thereby contributing to both our physical and mental well-being; they are the primary component for communication via optical fibers and a key component in electronic devices such as protective cover and/or dielectric material; and they enable clean energy production through solar panels or algae reactors by acting as protective and light transmitting barriers. Adding functions to transparent materials in an intelligent way creates further opportunities to use and enhance the beneficial impacts of transparency. The concept Transparent Intelligence covers transparent materials and products with integral intelligent functions – passive, active or interactive. By using Transparent Intelligence it is possible to embrace many of the societal challenges that we are facing today. The concept can be divided into five broad industrial sectors: Built Environment, Information and Communication Technologies (ICT), Solar Energy, Mobility, and Materials. A perspective on how Transparent Intelligence can improve the sustainable development of our world will be presented, using examples of electrochromic windows for energy-efficient buildings, photocatalytic coatings for improved indoor air quality, transparent conductive coatings for antennas, bandpass filters for mobile phone indoor coverage, UV down-converting components for efficient solar energy, hygienic surfaces for infection mitigation on electronic devices, printed electronics for sustainable glass packaging, and IR-reflecting coatings for fire safety.

  • 121.
    Khalili, Pooria
    et al.
    Chalmers University of Technology, Sweden.
    Blinzler, Brina
    Chalmers University of Technology, Sweden.
    Kádár, Roland
    Chalmers University of Technology, Sweden.
    Bisschop, Roeland
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Försth, Michael
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety. Luleå University of Technology, Sweden.
    Blomqvist, Per
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Flammability, smoke, mechanical behaviours and morphology of flame retarded natural fibre/Elium® composite2019Inngår i: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 12, nr 7, artikkel-id 2648Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The work involves fabrication of natural fibre/Elium® composites using resin infusion technique. The jute fabrics were treated using phosphorus-carbon based flame retardant (FR) agent, a phosphonate solution and graphene nano-platelet (GnP), followed by resin infusion, to produce FR and graphene-based composites. The properties of these composites were compared with those of the Control (jute fabric/Elium®). As obtained from the cone calorimeter and Fourier transform infrared spectroscopy, the peak heat release rate reduced significantly after the FR and GnP treatments of fabrics whereas total smoke release and quantity of carbon monoxide increased with the incorporation of FR. The addition of GnP had almost no effect on carbon monoxide and carbon dioxide yield. Dynamic mechanical analysis demonstrated that coating jute fabrics with GnP particles led to an enhanced glass transition temperature by 14%. Scanning electron microscopy showed fibre pull-out locations in the tensile fracture surface of the laminates after incorporation of both fillers, which resulted in reduced tensile properties. © 2019 by the authors.

  • 122.
    Kiuru, Risto
    et al.
    Geofcon, Finland.
    Heikkinen, Eero
    Pöyry Finland Oy, Finland.
    Jacobsson, Lars
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Kovacs, Dorottya
    University of Szeged, Hungary.
    EDZ Study Area in ONK-TKU-3620: Petrophysical, Rock Mechanics and Petrographic Testing and Analysis Conducted on Drill Core Specimens between 2014 and 20162019Rapport (Annet vitenskapelig)
    Abstract [en]

    Physical and mechanical properties of drill core specimens were determined as a part of investigations into excavation damage in the dedicated study area in ONK-TKU-3620. Additionally, microfractures in 16 specimens from drillholes ONK-SH32 and ONK-SH39 were analysed and used as a basis for fractals based discrete fracture network modelling.

    Best indicators for excavation damage, based on this study, would appear to be resistivity, S-wave velocity, and elastic parameters that are derived from S-wave velocity. The effects seemed to be mostly limited to pegmatoid specimens. Same properties also distinguished anomalous specimens, typically from shallow depths, some of which could be directly linked to visible EDZ features. 

    Comparing the crack initiation stress values to prior data from specimens saturated with non-saline water, similar results were obtained. This suggests that whatever chemical corrosion the saline water may have inflicted on the specimens has happened prior to sampling in situ, and that the decrease in strength compared to dry specimens is mainly due to water content, rather than the type of water.

    It was concluded that the difference in resistivity between pegmatoid and gneissic specimens of similar porosity was likely due to differences in the types of microfractures. This hypothesis was later confirmed from the thin sections and simulation: fractures in VGN were short and mostly in one preferred orientation, whereas the fractures in PGR were longer and had two preferred orientations. This suggests that VGN and PGR may suffer different types of excavation damage. Based on simulation results, the number of large fracture clusters and maximum number of fractures per cluster seem to increase with increasing volumetric PGR content. The interconnectivity of microfractures however seems to be negligible.

    No depth dependencies in geometric parameters of the microfractures were observed, while differences between VGN and PGR were observed. This suggests that excavation does not cause detectable disturbance of the intact rocks’ microfracture porosity, and that the disturbed layer observed by geophysical methods may be caused by larger scale fractures not present in the relatively intact specimens.

  • 123.
    Koukounas, Dimitrios
    et al.
    Chalmers University of Technology, Sweden.
    Eskilsson, Claes
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety. Aalborg University, Denmark.
    Engsig-Karup, Allan P.
    DTU Technical University of Denmark, Denmark.
    Numerical simulations of Peregrine breathers using a spectral element model2018Inngår i: Proceedings of the 37th International Conference on Ocean, Offshore and Arctic EngineeringOMAE 2018June 17-22, 2018, Madrid, Spain, 2018, Vol. 11A, artikkel-id OMAE2018-77648Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Breather solutions to the nonlinear Schrödinger equation have been put forward as a possible prototype for rouge waves and have been studied both experimentally and numerically. In the present study, we perform high resolution simulations of the evolution of Peregrine breathers in finite depth using a fully non- linear potential flow spectral element model. The spectral ele- ment model can accurately handle very steep waves as illustrated by modelling solitary waves up to limiting steepness. The an- alytic breather solution is introduced through relaxation zones. The numerical solution obtained by the spectral element model is shown to compare in large to the analytic solution as well as to CFD simulations of a Peregrine breather in finite depth pre- sented in literature. We present simulations of breathers over variable bathymetry and 3D simulations of a breather impinging on a mono-pile.

  • 124.
    Kozlowski, Marcin
    et al.
    Silesian University of Technology,Poland; Lund University, Sweden.
    Lenk, Peter
    ARUP, UK.
    Dorn, Michael
    Linnaeus University, Sweden.
    Honfi, Daniel
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Sjöström, Johan
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Structural Considerations on Timber-Glass Composites at Fire Scenarios2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper focuses on a recently developed concept, in which glass is combined with timber to provide post-breakage strength and ductility. This combination allows for good post-breakage performance and overall robustness of timber-glass composite beams and wall elements, which has been reported in several publications. The application of timber-glass elements in practice, however, raises important issues related to structural fire performance. The paper elaborates on this issue and provides general information about the behavior of glass, timber and adhesives at elevated temperatures and under fire conditions. Furthermore, it presents ideas and strategies developed for potential application of timber-glass composites in practical situations. The paper presents also initial results from an on-going research project on fire performance of timber-glass composites.

  • 125.
    Kozłowski, Marcin
    et al.
    Silesian University of Technology, Poland; Lund University, Sweden.
    Bedon, Chiara
    University of Trieste, Italy.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Numerical Analysis and 1D/2D Sensitivity Study for Monolithic and Laminated Structural Glass Elements under Thermal Exposure2018Inngår i: Materials, ISSN 1996-1944, E-ISSN 1996-1944, Vol. 11, nr 8, artikkel-id E1447Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Glass is largely used in architectural and engineering applications (i.e., buildings and vehicles) as a structural material, especially in the form of laminated glass (LG) sections. To achieve adequate and controlled safety levels in these applications, the well-known temperature-dependent behavior of viscoelastic interlayers for LG sections should be properly accounted for during the design process. Furthermore, the materials' thermomechanical degradation with increases of temperature could severely affect the load-bearing performance of glass assemblies. In this context, uncoupled thermomechanical finite element (FE) numerical models could represent a robust tool and support for design engineers. Key input parameters and possible limits of the FE method, however, should be properly calibrated and assessed, so as to enable reliable estimations for the real behavior of glazing systems. In this paper, FE simulations are proposed for monolithic (MG) and LG specimens under radiant heating, based on one-dimensional (1D) and two-dimensional (2D) models. A special attention is focused on thermal effects, being representative of the first step for conventional uncoupled, thermomechanical analyses. Based on experimental results available in the literature, FE parametric studies are discussed, giving evidence of limits and issues due to several modeling assumptions. In particular, careful consideration is paid for various thermal material properties (conductivity, specific heat) and thermal boundaries (conductivity, emissivity), but also for other influencing parameters like the geometrical features of samples (thickness tolerances, cross-sectional properties, etc.), the composition of LG sections (interlayer type, thickness), the loading pattern (heat transfer distribution) and the presence of additional mechanical restraints (i.e., supports of different materials). Comparative FE results are hence critically discussed, highlighting the major effects of such influencing parameters.

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  • 126.
    Kuznecovs, Artjoms
    et al.
    Chalmers University of Technology, Sweden.
    Ringsberg, Jonas
    Chalmers University of Technology, Sweden.
    Yang, Shun Han
    Chalmers University of Technology, Sweden.
    Johnson, Erland
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Anderson, Andreas
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    A methodology for design and fatigue analysis of power cables for wave energy converters2019Inngår i: International Journal of Fatigue, ISSN 0142-1123, E-ISSN 1879-3452, Vol. 122, s. 61-71Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The recent development of subsea power cables for various offshore marine renewable energy technologies has identified the need for new cables that have low structural stiffness properties. This type of cable is referred to as dynamic cable because of its high bending flexibility compared to static cables. The current study presents a cable design model and simulation models that were developed for the design and fatigue analysis of dynamic cables. These models were applied on a subsea dynamic power cable with a design that is suitable for a floating point-absorbing wave energy converter (WEC), where the cable must withstand cyclic loads imposed by the motions of the WEC, the waves and the ocean currents. The cable design model is presented with its detailed design and dimensioning methodology for cables with multiorder helical structures, with respect to desired (target) mechanical properties. The cable design model is verified against a verification study in the literature. A simulation model of a fatigue test rig for accelerated rotational bending is presented. The results from the numerical simulations and the subsequent fatigue analyses are compared against results from experiments using the test rig. The influence of the dynamic effects and mechanical properties on the fatigue life of the cable is discussed. This study contributes to a better understanding of the fatigue failure mechanisms of the cable, and it also highlights the importance of further development of numerical models.

  • 127.
    Lang, Xiao
    et al.
    Chalmers University of Technology, Sweden.
    Yang, SH
    Ringsberg, Jonas
    Chalmers University of Technology, Sweden.
    Johnson, Erland
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Rahm, Magnus
    Chalmers University of Technology, Sweden.
    Guedes Soares, Carlos
    Univerisity of Lisbon, Portugal.
    Comparison betweenfull-scale measurements and numerical simulations of mooring forces in afloating point-absorbing WEC system.2018Inngår i: Advances in Renewable Energies Offshore - Proceedings of The 3rdInternational Conference on Renewable Energies Offshore (RENEW 2018),, 2018, s. 865-876Konferansepaper (Fagfellevurdert)
  • 128.
    Lange, David
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Boström, Lars
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    A round robin study on modelling the fire resistance of a loaded steel beam2017Inngår i: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 92, s. 64-76Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper details a round robin study of the calculated response of structures in fire. In this instance, the study is based on one of two fire tests which were conducted on steel beams in a horizontal fire resistance furnace. The two specimens in the tests were identical having come from the same cast flow. The tests were conducted according to EN 1365-3 and the steel beams had a total length 5.4 m, spanning 5.2 m. These tests also formed a part of a testing round robin, reported elsewhere. The calculations were conducted by round robin participants in two stages. In the first instance a prediction of the response was made without knowledge of the measured temperatures of the steel beam and with only the grade of steel and details of the test setup. In the second instance the participants were also given the measured elastic limit of the steel, which differed significantly from the elastic limit implied by the grade, as well as measured temperatures from the steel beam and the plate thermometers from the furnace and asked to refine their model. Statistical analysis of the round robin results are presented to illustrate the variation which arises in the results of calculations. The results of the round robin study serve to illustrate the fire research and testing community's capability for modelling this simple case as well as the uncertainty in the calculation results. The results of the calculation round robin are also compared with the testing round robin to illustrate the comparative certainty between testing and calculations.

  • 129.
    Lange, David
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Novel techniques and approaches for risk based application of resilience concepts to critical infrastructure: An introduction to the IMPROVER project2017Inngår i: Risk, Reliability and Safety: Innovating Theory and Practice - Proceedings of the 26th European Safety and Reliability Conference, ESREL 2016, 2017, s. 2168-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The impact of disasters and crises in Europe is char-acterised by a highly interconnected society–a society which is increasingly reliant on critical infrastructures providing services which are centralised, if not terri-torially then contextually. Through cascading failures through interdependent systems the indirect consequences of natural and man-made disasters may be more severe than expected.

  • 130.
    Lange, David
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Resilient infrastructures for resilient communities2017Inngår i: Proceedingsof the 12th International Conference on Structural Safety and Reliability: Safety,Reliability, Risk, Resilience and Sustainability of Structures andInfrastructure, 2017, s. 3155-3164Konferansepaper (Fagfellevurdert)
  • 131.
    Lange, David
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Theocharidou, Marianthi
    European Commission Joint Research Centre, Italy.
    Giannopoulos, Georgios
    European Commission Joint Research Centre, Italy.
    Reitan, Nina Kristine
    RISE - Research Institutes of Sweden, Säkerhet och transport, Fire Research Norge.
    Storesund, Karolina
    RISE - Research Institutes of Sweden, Säkerhet och transport, Fire Research Norge.
    Incorporation of resilience assessment in critical infrastructure risk assessment frameworks2017Inngår i: Safety and Reliability - Theory and Applications - Proceedings of the 27th European Safety and Reliability Conference, ESREL 2017, CRC Press/Balkema , 2017, s. 1031-1038Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper explores the concept of Critical Infrastructure (CI) resilience and its relationship with current Risk Assessment (RA) processes. It proposes a framework for resilience assessment of CI, which integrates the resilience paradigm into the RA process according to ISO 31000. The framework consists of three levels, namely (a) asset (focus on individual CI assets), (b) system (focus on dependencies between CI assets) and (c) national or regional (focus on societal aspects). It is applicable to individual CI or their combinations, accounting both for existing RA processes, for interdependencies and their effect on interconnected CI, while at the same time employing current, available resilience analysis tools and methodologies. This approach is also compatible with the current European guidelines for national RA applied by the EU Member States. © 2017 Taylor & Francis Group, London.

  • 132.
    Lange, David
    et al.
    University of Queensland, Australia.
    Rush, David
    University of Edinburgh, UK.
    Bostrom, Lars
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Wickström, Ulf
    Luleå University of Technology, Sweden.
    Byström, Alexandra
    Luleå University of Technology, Sweden.
    Olsson, Kim
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Triantafyllidis, Zafiris
    University of Edinburgh, UK.
    The Tisova fire test part 2: heat transfer analysis2018Rapport (Annet vitenskapelig)
    Abstract [en]

    This report is the second of two reports into the Tisova fire test. It compares the results of three different groups’ attempts to model the temperature response of the structure in Tisova which was subject to a large scale travelling fire test. Generally it is observed that the different approaches have relatively close results, although one shows systematically hotter temperatures closer to the heated surface than the others; and differences between all three increase further from the heated surface.A comparison between the average calculated results and the experimental results is also shown for illustration. While an absolute comparison is not attempted because of experimental errors present the results do show the possible need for further data to support the heat transfer analysis required to carry out structural design for travelling fires.

    Fulltekst (pdf)
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  • 133.
    Lange, David
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Rush, David
    The University of Edinburgh, UK.
    Dai, Xu
    The University of Edinburgh, UK.
    Boström, Lars
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    The Tisova fire test part 1: test report2018Rapport (Annet vitenskapelig)
    Abstract [en]

    This report is a summary of the Tisova fire test, conducted in the Czech Republicin January 2015. It is the first of two reports into these test, and describes thebuilding, the experimental setup and discusses the results obtained on the day ofthe test. The results are discussed with a specific focus on the travelling nature ofthe fire in the building, since one of the objectives of the test was to provide anexperimental data set for validation of traveling fire models. To this end theproject was partially successful, since as is discussed a number of factorscontributed to slow fire spread and the need to alter the conditions of the testwhile it was ongoing by adding a mixture of diesel and gasoline to part of the fuelbed. This was needed in order to ensure that the test fulfilled the second of itsmain objectives – to provide a dataset of the response of a real structure exposedto a structurally challenging fire for the purposes of carrying out a round robinexercise of the response. This round robin will be reported in the second of thisreport series.Key conclusions from the test were that while we observed a travelling fire, thefire dynamics which lead to this and which contribute to the evolution of such afire need to be better understood.

    Fulltekst (pdf)
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  • 134.
    Larsson, Fredrik
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Elektronik.
    Anderson, Johan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Andersson, Petra
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Mellander, Bengt-Erik
    Chalmers University of Technology, Sweden.
    Safer battery systems in electrified vehicles – an electrified bus perspective2016Inngår i: Eurotransport, ISSN 1478–8217, Vol. 14, nr 3, s. 50-53Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    Lithium-ion (Li-ion) batteries offer great energy and power densities accompanied with long battery life time. However, if a mechanical fault occurs or the batteries over-heat, the flammable electrolyte of the Li-ion battery may pose a  risk. For Eurotransport, colleagues  from  the SP Technical Research Institute of Sweden (SP) and Chalmers University of Technology explore further, identifying the risks involved with electric buses.

  • 135.
    Larsson, Fredrik
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Elektronik. Chalmers University of Technology, Sweden.
    Andersson, Petra
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Blomqvist, Per
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Mellander, Bengt-Erik
    Chalmers University of Technology, Sweden.
    Toxic fluoride gas emissions from lithium-ion battery fires2017Inngår i: Scientific Reports, ISSN 2045-2322, Vol. 7, nr 1, artikkel-id 10018Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Lithium-ion battery fires generate intense heat and considerable amounts of gas and smoke. Although the emission of toxic gases can be a larger threat than the heat, the knowledge of such emissions is limited. This paper presents quantitative measurements of heat release and fluoride gas emissions during battery fires for seven different types of commercial lithium-ion batteries. The results have been validated using two independent measurement techniques and show that large amounts of hydrogen fluoride (HF) may be generated, ranging between 20 and 200 mg/Wh of nominal battery energy capacity. In addition, 15-22 mg/Wh of another potentially toxic gas, phosphoryl fluoride (POF3), was measured in some of the fire tests. Gas emissions when using water mist as extinguishing agent were also investigated. Fluoride gas emission can pose a serious toxic threat and the results are crucial findings for risk assessment and management, especially for large Li-ion battery packs.

    Fulltekst (pdf)
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  • 136.
    Larsson, Fredrik
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Elektronik. Chalmers University of Technology, Sweden.
    Andersson, Petra
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Mellander, Bengt-Erik
    Chalmers University of Technology, Sweden.
    Are electric vehicles safer than combustion engine vehicles?2017Inngår i: Systems Perspectives on Electromobility 2017 / [ed] Björn Sandén, Pontus Wallgren, Gothenburg: Chalmers University of Technology , 2017, s. 34-48Kapittel i bok, del av antologi (Annet vitenskapelig)
    Fulltekst (pdf)
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  • 137.
    Larsson, Fredrik
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Elektronik. Chalmers University of Technology, Sweden.
    Andersson, Petra
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Mellander, Bengt-Erik
    Chalmers University of Technology, Sweden.
    Lithium-Ion Battery Aspects on Fires in Electrified Vehicles on the Basis of Experimental Abuse Tests2016Inngår i: Batteries, ISSN 2313-0105, Vol. 2, nr 9, s. 1-13Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Safety issues concerning the use of large lithium-ion (Li-ion) batteries in electrified vehicles are discussed based on the abuse test results of Li-ion cells together with safety devices for cells. The presented abuse tests are: overcharge, short circuit, propane fire test and external heating test (oven). It was found that in a fire, cells with higher state of charge (SOC) gave a higher heat release rate (HRR), while the total heat release (THR) had a lower correlation with SOC. One fire test resulted in a hazardous projectile from a cylindrical cell. In the fire tests, toxic gas emissions of hydrogen fluoride (HF) were measured for 100%, 50% and 0% SOC.

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  • 138.
    Larsson, Ida
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Lönnermark, Anders
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Blomqvist, Per
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Persson, Henry
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Measurement of self‐heatingpotential of biomass pellets with isothermal calorimetry2017Inngår i: Fire and Materials, ISSN 0308-0501, E-ISSN 1099-1018, Vol. 41, nr 8, s. 1007-1015Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In order to assess the risk for spontaneous combustion of biomass pellets during storage it is important to know how prone the fuel is to self-heating, i.e. to determine the reactivity. 

    This article presents the results from isothermal calorimetry tests performed on 31 different biomass pellet batches. The purpose of the tests has been to characterize pellets by measuring the reactivity and investigate how the pellet composition influences the heat release rate and thereby the self-heating potential of pellets. 

    The results from the tests clearly indicate that there is a significant difference in reactivity between different types of pellets. The tested high reactive pellet batches reached maximum specific heat release rates (HRRmax) of 0.61-1.06 mW/g while pellet batches with low reactivity showed HRRmax of 0.05-0.18 mW/g. The tested batches were primarily ranked based on HRRmax but an alternative ranking based on specific total heat release rate during the test period was also used for comparison. 

    The test results also indicate that pine/spruce mix pellets are significantly more reactive than all other types of pellets tested and that pellets consisting of 100 % pine are more reactive than pellets consisting of 100 % spruce. Pellets produced from wine pruning/grape pomace (winery wastes), straw or eucalyptus are not very reactive compared to pellets consisting of pine/spruce. 

    The results also show that the reactivity of the pellets can be reduced by either introducing certain kinds of anti-oxidants into the pellets or by extracting lipids from the raw material of pellets.

  • 139.
    Larsson, Ida
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Lönnermark, Anders
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Blomqvist, Per
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Persson, Henry
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Bohlén, Haleh
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Development of a screening test based on isothermal calorimetry for determination of self-heating potential of biomass pellets2017Inngår i: Fire and Materials, ISSN 0308-0501, E-ISSN 1099-1018, Vol. 41, nr 8, s. 940-952Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For the risk for spontaneous combustion in storage of biomass pellets to be assessed, it is important to know how prone the fuel is to self-heating. There are traditional methods that are used to determine self-heating characteristics of fuels, eg, basket heating tests. The results from basket heating tests indirectly give the reactivity from a series of tests at high temperatures. This paper presents a sensitive screening test procedure for biomass pellets using isothermal calorimetry for direct measurement of the heat production rate at typical bulk storage temperatures. This method can be used to directly compare the reactivity of different batches of biomass pellets. The results could be used, eg, by storage security managers to gain better knowledge of their fuels propensity for self-heating and thereby for safer storage. A large number of tests have been performed to develop the test procedure presented. Different parameters, such as temperature, type of the test sample (powder/crushed or pellets), mass of test sample, and preheating time, have been varied. Furthermore, gas concentrations in the sample ampoule have been measured before and after some tests to study the oxygen consumption and the formation of CO and CO2. Three different types of pellets with different characteristics were tested to assess the variation in behaviour. Based on these tests, a screening test procedure is presented with a test temperature of 60°C, a sample size of 4 g, a 15-minute preheating period at the test temperature, and 24-hour test duration.

  • 140.
    Larsson Ivanov, Oskar
    et al.
    Lund University, Sweden.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Byggteknik.
    Santandrea, Fabio
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Stripple, Håkan
    IVL, Sweden.
    Consideration of uncertainties in LCA for infrastructure using probabilistic methods2019Inngår i: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 15, nr 6, s. 711-724Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The construction and usage of transport infrastructure are major causes of greenhouse gas emissions and energy consumption. The effects of resource consumption and pollutant emissions are often quantified through Life Cycle Assessment (LCA) models. All decisions made in infrastructure projects during the whole life cycle are afflicted by uncertainty, e.g. physical properties of materials or amount of pollutants emitted by certain processes. The pervasive role of uncertainty is reflected in LCA models, which therefore should consider uncertainty from various sources and provide a sound quantification of their effects. The aim of the work presented in this paper is to give an overview of different sources of uncertainty in LCA of infrastructure projects and to describe systematic methods to evaluate their influence on the results. The possibility of including uncertainty in a LCA-tool for infrastructure is presented, studying the sensitivity of the model output to the input parameters and two alternative approaches for propagation of uncertainty using two case studies. It is shown that, besides the influence of uncertainty in emission factors, other inputs such as material amounts and service life could contribute significantly to the variability of model output and has to be considered if reliable results are sought. © 2019, © 2019 The Author(s).

  • 141.
    Larsson Ivanov, Oskar
    et al.
    Lund University, Sweden.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Santandrea, Fabio
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Stripple, Håkan
    IVL, Sweden.
    ProLCA—treatment of uncertainty in infrastructure LCA2018Inngår i: Life Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision, 2018, s. 2923-2930Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The construction, operation and maintenance of transportation infrastructure require energy and materials which impact the environment. Large infrastructure projects thus use resources intensively and leave a significant environmental footprint. To demonstrate and support the sustainability of such large-scale projects, life cycle assessment (LCA) has become a common tool to evaluate environmental impacts in all stages of infrastructure life cycle, from raw material production through end-of-life management. However, the various phases of the assessment are all associated with uncertainties. If decisions are made without consideration of these uncertainties, they might be misleading and suboptimal. In this paper, results are presentedwhere variations associated with different parameters and tools for life cycle assessment have been considered using probabilistic methods. A categorization of common uncertainties in LCA is also included. The most influential parameters can be identified with sensitivity analysis methods, since for LCA with a large number of parameters it may be unreasonable to incorporate all in a probabilistic simulation. For a limited amount of influential variables, Monte Carlo simulation has been used to assess the effects of uncertainties on the results.A bridge has been used as a case study to find important aspects in infrastructure LCA. The results indicate that if the most influential parameters are considered as random variables, it is possible to estimate the uncertainty and increase the validity of the life cycle assessment.

  • 142.
    Leander, John
    et al.
    KTH Royal Institute of Technology, Sweden.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Björnsson, Ívar
    Lund University, Sweden.
    Risk-based planning of assessment actions for fatigue life prediction2017Inngår i: procedia structural integrity, Vol. 5, s. 1221-1228Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    It is vital to extend the service life of existing bridges as far as possible as a means for improved sustainability leading to reduced economic cost and resource consumption. This requirement is especially valid for bridges which are critical components of highly vulnerable infrastructure systems. Achieving this aim requires enhanced methods involving various actions and methods influencing different aspects of the assessment process. A framework is presented in this paper based on three common factors used to describe the assessment actions of existing bridges; (i) model sophistication, (ii) uncertainty consideration, and (iii) knowledge content. The framework elucidates the influence of different decisions on the assessment process and facilitates the planning of appropriate assessment actions. Furthermore, it provides a basic scheme for a risk-based decision analysis for determining suitable assessment actions or activities. A fatigue assessment of an existing bridge detail is used to demonstrate the application of the framework in practical cases.

    Fulltekst (pdf)
    fulltext
  • 143.
    Leander, John
    et al.
    KTH Royal Institute of Technology, Sweden.
    Honfi, Daniel
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Larsson Ivanov, Oskar
    Lund University, Sweden.
    Björnsson, Ivar
    Lund University, Sweden.
    A decision support framework for fatigue assessment of steel bridges2018Inngår i: Engineering Failure Analysis, ISSN 1350-6307, E-ISSN 1873-1961, Vol. 91, s. 306-314Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Many bridges are approaching or have already passed their expected service life. For steel bridges, fatigue is often the decisive degradation phenomenon that theoretically puts restrictions on a continued use. At the same time, fatigue is also afflicted with large uncertainties on the resistance side as well as on the action effect side. An accurate assessment of the service life will require measures outside the governing regulations but understanding what steps to take and how to consider the outcome for decisions on interventions can be a difficult task for a non-expert. This paper presents possible assessment actions and a decision support framework for rational decisions on interventions to extend the theoretical service life of existing bridges. A case study of a critical railway bridge is incorporated to demonstrate the framework. The aim is to provide a tool for bridge managers on how to evaluate and procure different assessment actions.

  • 144.
    Leroux, Jerome
    et al.
    Bureau Veritas, France.
    Evegren, Franz
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Gustin, Lisa
    Stena Line, Sweden.
    Ukaj, Kujtim
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Vicard, Blandine
    Bureau Veritas.
    FIRESAFE II Combined Assessment2018Rapport (Annet vitenskapelig)
    Abstract [en]

    In 2016, EMSA initiated the first FIRESAFE study in order to investigate cost-efficient measures for reducing the risk from fires on ro-ro spaces with a focus on Electrical Fire as ignition source as well as Fire Extinguishing Failure. In 2017, EMSA initiated the FIRESAFE II study to investigate risk control options in relation to Detection and Decision as well as Containment and Evacuation, following a ro-ro space fire incident on any ro-ro passenger ship.The main objective of FIRESAFE and FIRESAFE II was to improve the fire safety of ro-ro passenger ships by cost-efficient safety measures reducing the risk of ro-ro space fire, with an aim to discuss specific proposals for rule making.This report presents the results of the combined assessment of cost effectiveness based on the results from the different parts previously considered separately in FIRESAFE and FIRESAFE II.The combined cost-effectiveness assessment was performed on 21 Risk Control Options (RCOs) for three generic ships representing the world fleet of RoPax ships (Cargo, Standard and Ferry RoPax), taking into account potential differences between Newbuildings and Existing ships.Recommendations for decision making were provided based on the results of the combined cost-effectiveness assessment.

  • 145.
    Leroux, Jerome
    et al.
    Bureau Veritas.
    Mindykowski, Pierrick
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Evegren, Franz
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Gustin, Lisa
    Stena Rederi.
    Faivre, Jerome
    Bureau Veritas.
    Frösing, Mattias
    Stena Rederi.
    Lottkärr, Joacim
    Stena Rederi.
    Ukaj, Kujtim
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Vicard, Blandine
    Bureau Veritas.
    FIRESAFE II Containment and Evacuation2018Rapport (Annet vitenskapelig)
    Abstract [en]

    Fire and smoke containment are well known issues during fires in ro-ro spaces, especially in case of uncontrolled fires. Similarly, in some accidents, evacuation systems remained inoperative due to the heat and flames coming through the openings of the ro-ro spaces.This report presents a Formal Safety Assessment on containment and on evacuation following a ro-ro space fire incident on any ro-ro passenger ship.The safety level was estimated for three generic ships representing the world fleet of RoPax ships (Cargo, Standard and Ferry RoPax) and a cost-effectiveness assessment was performed on three Risk Control Options (RCOs), taking into account potential differences between newbuildings and existing ships.From a containment perspective, the RCO Fire monitors on weather decks was found cost-effective for newbuildings and existing ships of the three ship categories.From an evacuation outlook, a safe distance was estimated to ensure the protection of stowage areas, embarkation stations and evacuation routes, and LSA failure due to heat and smoke following a fire in a ro-ro space. Several design solutions were investigated and cost-effective solutions were found for the Standard RoPax and Ferry RoPax.

  • 146.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Effect of cross section on critical velocity in longitudinally ventilated tunnel fires2017Inngår i: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, s. 303-311Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Numerical and theoretical work was conducted to investigate the effect of tunnel cross section on critical velocityfor smoke control in longitudinally ventilated tunnel fires. The results show that for small fires, the criticalvelocity decreases with both the increasing tunnel height and tunnel width. For large fires, the critical velocitysignificantly increases with the increasing tunnel height but is independent of tunnel width. Differentcalculation models are compared with a focus on effect of tunnel cross section. A new correlation is proposedto account for the effect of tunnel width based on the previous model.

  • 147.
    Li, Ying Zhen
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Study of fire and explosion hazards of alternative fuel vehicles in tunnels2019Inngår i: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 110, artikkel-id 102871Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper presents results concerning fire and explosion hazards of various alternative fuel vehicles in tunnels. The alternative fuels are divided into four types: liquid fuels, liquefied fuels, compressed gases, and electricity, and detailed parameters are obtained. Three important types of fire hazards: pool fires, jet fires and fireballs are identified and investigated. From the perspective of pool fire size, the liquid fuels pose equivalent or even lower fire hazards compared to traditionally used fuels, but the hazards of liquefied fuels may be higher. For pressurized tanks, fires are generally much larger in size but shorter in duration. The gas releases from pressure relief devices and the resulting jet flames are highly transient. For hydrogen vehicles, the fire sizes are significantly higher compared to CNG tanks, while flame lengths are only slighter longer. Analysis of the peak overpressure in case of an explosion in a tunnel shows that the consequences of tank rupture and BLEVE are relatively tolerable for a position further than 100 m away, but the situations in case of a cloud explosion are highly severe and intolerable for tunnel users in most cases. These hazards need to be carefully considered in both vehicle safety design and tunnel fire safety design. 

  • 148.
    Li, Ying Zhen
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Huang, Chen
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Anderson, Johan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Svensson, Robert
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Husted, Bjarne
    Lund University, Sweden.
    Runefors, Marcus
    Lund University, Sweden.
    Wahlqvist, Jonatan
    Lund University, Sweden.
    Verification, validation and evaluation of FireFOAM as a tool for performance design2017Rapport (Annet vitenskapelig)
    Abstract [en]

    The open source CFD code FireFOAM has been verified and validated against analytical solution and real fire tests. The verification showed that FireFOAM solves the three modes of heat transfer appropriately. The validation against real fire tests yielded reasonable results. FireFOAM has not been validated for a large set of real fires, which is the case for FDS. Therefore, it is the responsibility of the user to perform the validation, before using the code. One of the advantages of FireFOAM compared to the Fire Dynamic Simulator is that FireFOAM can use unstructured grid. FireFOAM is parallelised and scales reasonable well, but is in general considerably slower in computation speed than the Fire Dynamic Simulator. Further, the software is poorly documented and has a steep learning curve. At present it is more a tool for researchers than for fire consultants.

    Fulltekst (pdf)
    fulltext
  • 149.
    Li, Ying Zhen
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Analysis of Muskö tunnel fire flows with automatic sprinkler activation2017Rapport (Annet vitenskapelig)
    Abstract [en]

    The focus of the present study is analyzing the best position of a sprinkler nozzle in a tunnel cross-section in the Muskö tunnel, south of Stockholm, Sweden. Activation of the sprinklers installed along the centerline and along the sidewall is investigated through analysis of full scale experiments and by three dimensional numerical modelling. Then the tunnel velocity is analyzed by one dimensional numerical modelling for various fire locations in the Muskö tunnel. For both activating the automatic sprinklers nearby the fire and avoiding activation of the sprinklers further downstream, the automatic sprinklers are recommended to be installed along the centerline of the tunnel. It has also been found that the tunnel velocity varies significantly with the fire location. When the fire is on the left side of the tunnel, the flow velocity mostly remains in a range of 1 m/s (positive or negative) within the first 10 minutes, which helps early activation of the automatic sprinklers. When the fire is on the right side of the tunnel, the flow velocity mostly remains within a range of -1 m/s and 1 m/s within the first 5 minutes, and the velocity mostly increases to 2 m/s at around 10 min. Therefore, the scenario for fire located on the left side is better than that for fire on the right side, especially when it is located between the middle of the right section and the right portal. As one typical case with fire on the right side, the tunnel velocity maintains at 1 m/s for the first 5 min and gradually increases to 2 m/s at 10 min. Under such conditions, the automatic sprinkler system is expected to perform well. 

    Fulltekst (pdf)
    RISE Rapport 2017:51
  • 150.
    Li, Ying Zhen
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Ingason, Haukur
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Discussions on critical velocity and critical Froude number for smoke control in tunnels with longitudinal ventilation2018Inngår i: Fire safety journal, ISSN 0379-7112, E-ISSN 1873-7226, Vol. 99, s. 22-26Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Determination of critical velocity is a key issue for smoke control in any tunnel with longitudinal ventilation. The critical Froude model using single Froude number of 4.5 has for decades been widely used in engineering applications. This value was originally used by Danziger and Kennedy and they argued that the critical Froude number obtained by Lee et al. was in a range of 4.5 and 6.7 and therefore a conservative value of 4.5 was obtained. This paper explores the validity of using single critical Froude number of 4.5 by investigating the original sources and comparing it to recent research results. It was found that the value of 4.5 obtained in the original source corresponds to a large tunnel fire and it correlates well with data from other literature within a narrow range of large fire sizes. Using this value produces a significantly lower critical velocity for a wide range of fire sizes and therefore it is not conservative. The Froude number of 6.7 obtained by Lee et al. corresponds to another Froude number with a different definition and it is therefore not comparable with the value of 4.5. It is found that the use of a single value of 4.5 for the critical Froude number is not reasonable in calculation of the critical velocity for smoke control in tunnels with longitudinal ventilation.

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