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  • 651.
    Wallentén, Petter
    et al.
    Lund University, Sweden.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden. Lund University, Sweden.
    SIRen: An Applied Framework for a Sustainable Renovation Process2021Inngår i: Sustainability, E-ISSN 2071-1050, Vol. 13, nr 10, artikkel-id 5412Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The renovation of buildings involves multidisciplinary issues and multistakeholder involvement, which makes the process complex to manage. The purpose of this paper is to present a transparent, openly accessible, adaptable framework to ensure a sustainable renovation process, covering the technical, environmental, economic, social, and cultural historical aspects to be considered by the various actors during the renovation process. A framework with an associated process was drawn up, focusing on practical usefulness together with the fundamental idea that sustainability cannot be a sub requirement but must be the overall requirement present in all stages of the process. The framework contains an overview, description of activities, links to external tools and documents, and finally a checklist to be completed after each stage. Depending on which stakeholder uses the framework, there are different examples and suggestions for activities and tools. Contrary to many other assessment schemes, the SIRen process focuses on the renovation process itself, and the self-evaluation gives a numerical value that represents to what extent the actors have considered and implemented different aspects of sustainability in the stages of the renovation process. The SIRen process was partially implemented in four renovation projects during the iterative development of the SIRen framework.

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  • 652.
    Wallqvist, Viveca
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material.
    Kjell, Gunnar B.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Cupina, Ena
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material. Chalmers Univeristy of technology, Sweden.
    Kraft, Lars
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, CBI Betonginstitutet.
    Deck, Caroline
    University of Strasbourg, France.
    Willinger, Rémy
    University of Strasbourg, France.
    New functional pavements for pedestrians and cyclists2017Inngår i: Accident Analysis and Prevention, ISSN 0001-4575, E-ISSN 1879-2057, Vol. 105, s. 52-63Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    When many fields of pedestrian and cyclist safety have been extensively studied, the surfacing has long been left unquestioned, despite being developed for another mode of transport and being one of the main causes for falls and fall injuries. In this project new surfacing materials for pedestrian and cyclist safety have been produced. Focusing on augmenting previously largely disregarded parameters as impact absorption, comfort and visibility at the same time as avoiding deteriorating of crucial parameters as friction and wear resistance. Rubber content, binder type, and pigment addition have been varied and evaluated. The results demonstrate that by increasing rubber content of the mixtures the head injury criterion (HIC) value and injury risk can be decreased while maintaining frictional properties according to existing criteria. Assembly of test-lanes demonstrate that some developed materials experience lower flow and component separation than standard materials due to rubber addition, calling for further optimisation of construction procedure linked to content development. Initial trials on the test-lanes indicate that a polyurethane (PU) based material has high cycling comfort, visibility and can be modified with phosphorescence properties. For standard asphalt, impact absorption might be inflicted by modification of bitumen alone but is mostly augmented by rubber addition. The results also indicate that rubber content can decrease ice formation on the materials.

  • 653.
    Wallqvist, Viveca
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, SP Kemi Material och Ytor.
    Kraft, Lars
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Prototype bike lanes - placement practices and properties2015Inngår i: 57º Congresso Brasileiro do Concreto, Bonito/MS [CBC 2015], IBRACON , 2015Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    AstaZero, a unique environment to build any scenario in order to develop, test or certifynew traffic safety solutions was opened 2014 in Sweden. In this environment a testingarena for vulnerable road users has been developed. Among with the solutions testedbelongs impact absorbing surfaces for cyclists, one which has been made of rubbermodified concrete. The study involved testing of different compositions and examining newproperties in the fresh state, which affected the production process to different extents. Forexample, due to difference in density between aggregate and rubber the segregation maybe a problem. Regarding the materials properties, the head injury criterion (HIC) was usedfor evaluation of the pavements shock absorbing capability. In the laboratory tests themodified concrete demonstrated a decrease in HIC-value by 85% compared to standardbitumen material. In the AstaZero test-lane, measured at -1°C, the decrease in HIC-valuecompared to reference was 79%. The frictional properties were approved according toexisting criteria. Future tests will determine the new materials’ durability, maintenance andcycling comfort.

  • 654.
    Wang, Tianxiang
    et al.
    KTH Royal Institute of Technology, Sweden.
    Wang, Yue
    KTH Royal Institute of Technology, Sweden.
    Debertolis, Mattia
    KTH Royal Institute of Technology, Sweden.
    Crocetti, Roberto
    KTH Royal Institute of Technology, Sweden.
    Wålinder, Magnus
    KTH Royal Institute of Technology, Sweden.
    Blomqvist, Lars
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Bonding strength between spruce glulam and birch plywood at different load-to-plywood face grain angles2024Inngår i: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736XArtikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    There is growing interest recently in reducing the usage of metals in timber structures. Birch plywood possesses satisfactory mechanical properties compared to other wood-based panels and is promising to be utilized in timber connections as a substitute for the more conventional slotted-in metal plate. There are essentially two possibilities to connect plywood plates and other timber elements by means of either mechanical connections or adhesively bonded connections. Despite the more commonly adopted mechanical connections in current timber structures, the adhesively bonded connections hold the distinct advantages of being more cost-effective, stiffer, and with a lower risk of moisture penetration in the timber elements. When employing birch plywood in timber structure applications such as trusses and frame corners, stresses from different directions need to be transmitted by the plywood gusset plate. However, it is still uncertain how the bonding strength is affected by different loading angles to the face grain. This research question, specifically concerning the bonding strength between birch plywood and spruce glulam, has been addressed in this paper. It was found that the bonding strength varies within a relatively small range when the load-to-plywood face grain angle varies from 0° to 90°, which is promising for the development of adhesively bonded joints. Failure mainly occurred in glulam at 0° and 15°; while at other angles, a mixture of cohesive failure in glulam and plywood face veneer was dominant. The weak angle-dependence of the bonding strength can be explained by further checking the shear strength of the weaker wood adherends between glulam and plywood. A strong positive correlation was observed between bonding strength and the wood shear strength. 

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  • 655.
    Wang, Yue
    et al.
    KTH Royal Institute of Technology, Sweden.
    Wang, Tianxiang
    KTH Royal Institute of Technology, Sweden.
    Debertolis, Mattia
    KTH Royal Institute of Technology, Sweden.
    Crocetti, Roberto
    KTH Royal Institute of Technology, Sweden.
    Wålinder, Magnus
    KTH Royal Institute of Technology, Sweden.
    Blomqvist, Lars
    RISE Research Institutes of Sweden, Bioekonomi och hälsa, Material- och ytdesign.
    Glulam frame corner joints built of birch plywood and mechanical fasteners: An experimental, analytical, and numerical study2024Inngår i: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 310, artikkel-id 118112Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study investigates frame corner joints built of birch plywood plates and glulam elements connected via self-tapping screws. Analytical calculations based on the fastener group’s torsional moment resistance, the proposed fastener group’s elastic and post-elastic load-bearing criteria, and the design formulas in Eurocode 5 were performed to predict the connection capacity in both elastic and post-elastic stages. A combined action check formula was adopted to predict the capacity of birch plywood plates and glulam elements. Frame corner specimens constructed with three different plywood thicknesses were planned to study the influence on global behavior and rotational stiffness. The specimens were intentionally designed so that failure occurred either in plywood or in glulam, in order to examine the robustness and validity of analytical calculation models. Another supplementary test group with 21 mm plywood and fewer fasteners was also designed and tested, in which the plastic yield of fasteners was expected. The test results of this supplementary group served to calibrate the analytical model that predicts the elastic and post-elastic capacity of the connection group. As a result of the comparison, the analytical calculations gave reasonable predictions on the failure of plywood, glulam, and the capacity of the fastener group. Only when the exposed moment exceeded the post-elastic limit of the fastener group did the plastic yielding of fasteners become observable. Moreover, numerical finite element models adopting the foundation zone-modeling scheme were constructed, which were proven to capture all test configurations’ linear loading stiffness satisfactorily. 

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  • 656.
    Wedvik, Barbro
    et al.
    NIKU The Norwegian Institute for Cultural Heritage Research, Norway.
    Storesund, Karolina
    RISE Research Institutes of Sweden, Säkerhet och transport, Brandteknik.
    Fire performance of escape route doors in cultural heritage buildings : A state-of-the-art review2020Rapport (Annet vitenskapelig)
    Abstract [en]

    The aim of this project was an inventory of the upgrading of old wooden doors for improved fire performance, to identify the key issues and find possibilities for the future. Expected benefit was an update of knowledge, as a preparation for reworking guidelines for improvement of fire resistance of old paneled doors as important parts of historic interiors. Technical solutions for fire rating as well as matrix-based risk assessment approaches for fire performance of timber doors in cultural heritage buildings are presented. A thesis that question the established interpretation of the fire safety regulations by looking into the cost-benefit ratio of upgrading is also presented. Further fire-testing of doors can serve as a basis for a revision of guidelines. Also, the implementation of a more risk-based approach to fire threats in old apartment houses and further investigations of the numbers behind interpretations of regulations - which fire safety measures that give the best effect/cost-benefit ratio – could be useful for the fire safety work in stairwells in the old apartment buildings. The results of the project are highly relevant at a regional and national level. The authors gratefully acknowledge the financial support by the Research Council of Norway and several partners through the Fire Research and Innovation Centre (www.fric.no).

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  • 657.
    Werner, Jennifer
    et al.
    Fraunhofer, Germany.
    Nowak, Dimitri
    Fraunhofer, Germany.
    Hunger, Franziska
    Fraunhofer, Sweden.
    Johnson, Tomas
    Fraunhofer, Sweden.
    Mark, Andreas
    Fraunhofer, Sweden.
    Gösta, Alexander
    RISE Research Institutes of Sweden, Samhällsbyggnad, Bygg och fastighet. Liljewall Arkitekter, Sweden.
    Edelvik, Fredrik
    Fraunhofer, Sweden.
    Predicting Wind Comfort in an Urban Area: A Comparison of a Regression- with a Classification-CNN for General Wind Rose Statistics2024Inngår i: Machine Learning and Knowledge Extraction, ISSN 2504-4990, Vol. 6, nr 1, s. 98-125Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Wind comfort is an important factor when new buildings in existing urban areas are planned. It is common practice to use computational fluid dynamics (CFD) simulations to model wind comfort. These simulations are usually time-consuming, making it impossible to explore a high number of different design choices for a new urban development with wind simulations. Data-driven approaches based on simulations have shown great promise, and have recently been used to predict wind comfort in urban areas. These surrogate models could be used in generative design software and would enable the planner to explore a large number of options for a new design. In this paper, we propose a novel machine learning workflow (MLW) for direct wind comfort prediction. The MLW incorporates a regression and a classification U-Net, trained based on CFD simulations. Furthermore, we present an augmentation strategy focusing on generating more training data independent of the underlying wind statistics needed to calculate the wind comfort criterion. We train the models based on different sets of training data and compare the results. All trained models (regression and classification) yield an (Formula presented.) -score greater than 80% and can be combined with any wind rose statistic.

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  • 658. Wiberg, Erik
    et al.
    Bremer, Peter
    RISE Research Institutes of Sweden, Säkerhet och transport, Elektrifiering och pålitlighet.
    Multifuel energy stations for cars, buses and trucks - Interreg Baltic Sea Region Project #R032 “Sustainable and Multimodal Transport Actions in the Scandinavian-Adriatic Corridor”: Technical Support Document2018Rapport (Annet vitenskapelig)
    Abstract [en]

    The report discusses the positive and negative effects of co-locating clean fuels with each other or with conventional fuels at multifuel energy stations (MES). The fuels considered as clean are CBG/CNG, LBG/LNG, hydrogen and fast charging of electrical vehicles. For hydrogen, CH2 has been considered in the study. However, to some extent aspects related to LH2 have been considered also. Multifuel energy stations are also referred to as “multifuel stations” and “multi energy stations” in this report. We have identified three station types; car station, truck station and bus depot. Those three use different fuels to some extent which also impact safety measures and station layout. Safety aspects with focus on explosion risks have been studied for the different clean fuels present at multifuel energy stations, as well as technical aspects of co-locating such fuels. From this material, conclusions have been drawn on the effects of offering clean fuels at multifuel energy stations. Car and bus stations are quite similar, but truck stations differ a bit due to liquefied gas being present and no fast charging is offered. The study and this report cover Sweden (SE), Norway (NO), Denmark (DK), Finland (FI) and Germany (DE) located along the Northern Scandria®Corridor, with the main focus on Sweden. This is a natural part of chapter 7: Safety for multifuel energy stations, and the technical and economical synergies have high transferability in general and they are therefore written in a non-country specific manner.

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  • 659.
    Williams Portal, Natalie
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Flansbjer, Mathias
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Assessment of Fire Exposed Concrete with Full-field Strain Determination and Predictive Modelling2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A condition assessment of civil engineering structures is typically performed after the occurrence of a fire incident to determine the remedial actions required out of a structural point of view. A condition assessment is based on the mapping of damage on the given structure, which is traditionally executed via methods that yield indirect results related to surface and/or geometric properties. To be able to predict the accurate fire resistance performance of a given structure, it is most suitable to apply a mapping method which can be directly coupled to the change in material properties of concrete at high temperatures. The aim of this study is to explore the potential of applying an innovative damage mapping methodology directly coupled to the change in material properties of concrete at high temperatures. This methodology consists of optical full-field strain measurements based on Digital Image Correlation (DIC) coupled with a predictive model based on finite-element analysis (FEA). An experimental study was firstly conducted to expose concrete slabs to a standard fire curve. Subsequently, compression tests were performed on drilled cores taken from the damaged induced specimens, all while optically measuring the full-field strain on a specimen surface. As a preliminary step, an FE model of a fire exposed core was developed based on input data from standard temperature-dependent properties. The analysis consisted of a sequentially coupled thermal stress analysis to solve the multiphysics problem. The model was able to capture the temperature distribution in the concrete with enough certainty given the choice of input data. The resulting strain along the height of the core was also comparable to the experimental optical strain measurements, particularly as the distance increased from the fire exposed surface. These results can be practical when assessing the required strengthening actions to restore the load carrying capacity and durability of the concrete structure.

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  • 660.
    Williams Portal, Natalie
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Flansbjer, Mathias
    RISE Research Institutes of Sweden, Material och produktion, Kemi och Tillämpad mekanik.
    Bäckstrand, Albin
    RISE Research Institutes of Sweden, Material och produktion, Kemi och Tillämpad mekanik.
    HCT-City - Bromätning i Varberg2023Rapport (Annet vitenskapelig)
    Abstract [sv]

    Projektet HCT City studerar hur HCT-konceptet (High Capacity Transport) kan appliceras i städer, genom piloter i Varberg och Stockholm samt analyser i Sundbyberg och Uppsala. I projektet testas hypotesen att HCT-konceptet kan förbättra både produktiviteten och transporteffektiviteten avsevärt och därmed minska utsläppen av CO2 och hälsovådliga emissioner, samtidigt som effekter avseende vägslitage och trafiksäkerhet minskas eller förblir oförändrade. Inom ramen för projektet har effekter adresserats vid utbyte av konventionella tunga fordon och kontroll mot HCT-fordon beträffande: trafiksäkerhet och påverkan/nedbrytning av gator, broar och vägar i tätorten. Denna rapport omfattar en fallstudie där kontrollerad fältmätning genomfördes på en utvald bro belägen på Österleden i Varberg. Mer specifikt utfördes deformationsmätning för att förstå konstruktionen verkningssätt beroende på bland annat fordonsvikt- och hastighet. De utförda mätningarna visar att brofarbanans nedböjning är generellt relativt liten och påkänningarna följaktligen är små vid passage av referensfordon och andra fordon under den aktuella mätperioden. Referensfordonets hastighet avspeglar sig i varaktigheten för brofarbanans nedböjning. Hastighet vid bropassagen verkar dock inte ha någon större inverkan på brofarbanans respons, vilket tyder på att den dynamiska effekten är liten för den aktuella bron.

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  • 661.
    Williams Portal, Natalie
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Tillämpad mekanik.
    Flansbjer, MathiasRISE Research Institutes of Sweden, Material och produktion, Tillämpad mekanik.Carró-Lopez, DiegoFernandez, Ignasi
    Analysis of tensile behavior of recycled aggregate concrete using acoustic emission technique2020Konferanseproceedings (Fagfellevurdert)
    Abstract [en]

    Recycled concrete aggregate (RCA) was processed from reinforced concrete edge beams sourced from a demolished bridge. This material replaced different ratios of coarse aggregate in a benchmark concrete. The tensile behavior of the developed concrete mixes was characterized via monotonic and cyclic uni-axial tensile tests performed on notched cylinders. Such tensile tests allow for the quantification of the fracture energy and softening behavior of the concrete. Moreover, acoustic emission (AE) measurements were conducted in conjunction with the cyclic tests to characterize e.g. micro-crack initiation and development, as well as crack localization. The tensile behavior of the various materials was found to be similar with minimal variation in the results. However, the softening behavior suggests that the RCA materials are slightly more brittle compared to both the mother and benchmark materials. The corresponding AE measurements also indicated similarities between the micro-crack initiation and development for these mixes. It can be constituted that if the concrete used to produce RCA is of high quality and from one source, the resulting RAC will have adequate tensile properties with minimal variation, despite the aggregate replacement ratio.

  • 662.
    Williams Portal, Natalie
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg. Chalmers University of Technology, Sweden.
    Flansbjer, Mathias
    RISE., SP – Sveriges Tekniska Forskningsinstitut. Chalmers University of Technology, Sweden.
    Johannesson, Pär
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Malaga, Katarina
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Lundgren, Karin
    Chalmers University of Technology, Sweden.
    Tensile behaviour of textile reinforcement under accelerated ageing conditions2016Inngår i: Journal of Building Engineering, E-ISSN 2352-7102, Vol. 5, s. 57-66Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Textile reinforced concrete (TRC) has emerged as a promising alternative wherein corrosion is no longer an issue and much thinner and light-weight elements can be designed. Although TRC has been expansively researched, the formalization of experimental methods concerning durability arises when attempting to implement and design such innovative building materials. In this study, accelerated ageing tests paired with tensile tests were performed. The change in physico-mechanical properties of various commercially available textile reinforcements was documented and evaluated. The ability for the reinforcements to retain their tensile capacity was also quantified in the form of empirical degradation curves. It was observed that accelerated test parameters typically applied to fibre-reinforced polymer (FRP) bars and grids are generally too aggressive for the textile reinforcement products and alternative boundary conditions are necessary. The developed degradation curves were found to have an overall good correlation with the experimental findings.

  • 663.
    Williams Portal, Natalie
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Flansbjer, Mathias
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Malaga, Katarina
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Anchorage of Textile Reinforcement in High-Performance Concrete2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The mechanical properties of textile reinforced high-performance concrete (TRHPC) applied in innovative lightweight sandwich elements has been investigated in the framework of EC supported FP7 project, H-House (Healthier Life with Eco-innovative Components for Housing Constructions). TRHPC offers new possibilities for architects and engineers to create thinner and more durable concrete façade elements. Textile reinforcement grids are typically woven from non-metallic rovings usually consisting of continuous glass, rock or carbon fibres. The most promising performing textile reinforcement alternative in terms of mechanical and durability performance consists of carbon fibres. Carbon fibres do however have an inherent smooth surface which is unfavourable concerning its bond to the cement paste, which is often improved by polymer-based coatings. The bond behaviour, being a critical design parameter, should be investigated for TRHPC in order to understand limitations regarding required anchorage lengths for use in applications such as façade elements. The aim of this study was to quantify and verify the required anchorage length for a selected epoxy impregnated carbon textile reinforced TRHPC combination. To achieve this aim, the bond behaviour, leading to a suitable anchorage length (or overlap), was firstly studied by means of pull-out tests. Thereafter, the ultimate strength of the composite material was measured via uniaxial tensile testing with and without an overlap splice according to the findings from the pull-out tests. Optical measurements during the pull-out tests were performed using a video extensometer technique and by Digital Image Correlation (DIC) for the uniaxial tensile tests. Results indicated that the required anchorage length to yield rupture of the textile reinforcement in pull-out was deemed appropriate as an overlapping length when tested in tension. The combination of these two experimental methods on the composite level was useful for determining the overlapping length required for the TRHPC which could be applied in larger scale applications.

  • 664.
    Williams Portal, Natalie
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Flansbjer, MathiasRISE - Research Institutes of Sweden, Säkerhet och transport, Safety.Mueller, UrsRISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Analysis of the Flexural Behavior of Textile Reinforced Reactive Powder Concrete Sandwich Elements Using Optical Measurements2018Konferanseproceedings (Fagfellevurdert)
    Abstract [en]

    Prefabricated and non-load bearing sandwich façade elements were developed using Textile Reinforced Reactive Powder Concrete (TRRPC) along with low density Foamed Concrete (FC) and Glass Fiber Reinforced Polymer (GFRP) continuous connecting devices. Four-point bending tests were performed on large-scale TRRPC sandwich element beams to characterize the structural performance, which included the flexural capacity, level of composite action, resulting deformation, crack propagation and failure mechanisms. Optical measurements based on Digital Image Correlation (DIC) were taken simultaneously to enable a detailed analysis of the underlying composite action. The structural behavior of the developed elements was found to be highly dependent on the stiffness and strength of the connectors to ensure composite action between the two TRRPC panels.

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  • 665.
    Williams Portal, Natalie
    et al.
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Flansbjer, Mathias
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Mueller, Urs
    RISE - Research Institutes of Sweden, Samhällsbyggnad, CBI Betonginstitutet.
    Experimental Study on Anchorage in Textile Reinforced Reactive Powder Concrete2017Inngår i: Nordic Concrete Research, ISSN 0800-6377, Vol. 57, nr 2, s. 73-88, artikkel-id 6Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The EC funded project SESBE (Smart Elements for Sustainable Building Envelopes) focused on utilizing new types of cementitious materials for reducing the mass and thickness of façade elements while increasing their thermal performance. A method enabling the quantification and verification of the required anchorage length for a given textile reinforced reactive powder concrete (TRRPC) is presented. At the material level, tensile tests were conducted to determine the tensile properties of the reinforcement. Pull-out tests were applied to quantify the required anchorage length, while uniaxial tensile tests were performed to quantify the ultimate strength and verify the suitability of the anchorage length at the composite level. The combination of these methods was deemed useful to determine the overlapping length required for larger scale façade applications.

  • 666.
    Williams Portal, Natalie
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, CBI Betonginstitutet.
    Flansbjer, Mathias
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Zandi, Kamyab
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, CBI Betonginstitutet.
    Wlasak, Lech
    Mostostal Warszawa SA, Poland.
    Malaga, Katarina
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, CBI Betonginstitutet.
    Bending behaviour of novel Textile Reinforced Concrete-foamed concrete (TRC-FC) sandwich elements2017Inngår i: Composite structures, ISSN 0263-8223, E-ISSN 1879-1085, Vol. 177, s. 104-118Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A novel sandwich element design consisting of two facings made of carbon reinforced Textile Reinforced Concrete (TRC), a low density foamed concrete (FC) core and glass fibre reinforced polymer (GFRP) connecting devices was experimentally investigated according to quasi-static and cyclic quasi-static fourpoint bending. Optical measurements based on Digital Image Correlation (DIC) were taken during testing to enable a detailed analysis of the bending behaviour and level of composite action. A model, verified by the experiments, was developed based on non-linear finite element analysis (NLFEA) to gain further insight on the failure mechanisms. Under both loading conditions, the bending behaviour of the TRCFC composite elements was characterized by favourable load bearing capacity, partial composite action, superior ductility and multiple fine cracking. The connecting devices were found to be the critical elements causing the initial failure mechanism in the form of localized pull-out within an element.

  • 667.
    Williams Portal, Natalie
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Korrosion.
    Prieto Rábade, Miguel
    RISE Research Institutes of Sweden, Material och produktion, Korrosion.
    Franciscangelis, Carolina
    RISE Research Institutes of Sweden.
    Sensor characteristics and implementation for tidal turbine foundation2022Rapport (Annet vitenskapelig)
    Abstract [en]

    The purpose of CF2T project is to develop a competitive foundation, immerse it as part of a precommercial project and validate the concept in a real sea environment. The innovative foundation will be designed to decrease construction costs, with modular interfaces to allow an installation in several packages (foundation parts, ballasts, turbine) in order to limit the installation vessel’s crane capacity requirement, which will also reduce installation costs. The different alternatives to reduce the structure construction costs and modularity will be evaluated including the design of a hybrid foundation combining concrete and steel. The new foundation should also have an adaptive interface with the seabed in order to avoid any seabed preparation. In addition, the project will develop a monitoring system to have a better understanding of loads applied to the structure for future foundations developments. This monitoring will allow to carry out a survey of the structural health for preventive maintenance which will contribute to improve reliability of the foundation. This report is the first deliverable in WP6 (Foundation Monitoring), namely D6.1 Sensor characteristics and implementation report. RISE led the work in collaboration with SAITEC and ALKIT. This report proposes sensor characteristics and implementation for the foundation of tidal turbine designed within the project. A literature review is firstly included on Structural Health Monitoring (SHM), relevant SHM techniques and SHM’s applicability to both concrete and offshore structures. Fibre optics, specifically Fibre Bragg Grating (FBG), were identified to be the most suitable solution for SHM of the concrete foundation. Critical measurement areas and performance indicators for the concrete foundation were identified and a detailed measurement scheme was proposed. Implementation on the laboratory scale was studied for both material and component levels, i.e., steel reinforcement and concrete surface. It was observed that the fibre optics were able to measure the distribution of strains coherently and accurately on steel reinforcement subjected to tensile loading, all while proving to be durable against high levels of corrosion. Detection of strain in the concrete surface which could indicate tilting and/or onset of cracking was also possible with the proposed fibre optic system.

    Fulltekst (pdf)
    fulltext
  • 668.
    Williams Portal, Natalie
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Korrosion.
    Prieto Rábade, Miguel
    RISE Research Institutes of Sweden, Material och produktion, Korrosion.
    Franciscangelis, Carolina
    RISE Research Institutes of Sweden.
    Sensors implemented and calibrated in proof-of-concept2022Rapport (Annet vitenskapelig)
    Abstract [en]

    The purpose of CF2T project is to develop a competitive foundation, immerse it as part of a precommercial project and validate the concept in a real sea environment. The innovative foundation will be designed to decrease construction costs, with modular interfaces to allow an installation in several packages (foundation parts, ballasts, turbine) in order to limit the installation vessel’s crane capacity requirement, which will also reduce installation costs. The different alternatives to reduce the structure construction costs and modularity will be evaluated including the design of a hybrid foundation combining concrete and steel. The new foundation should also have an adaptive interface with the seabed in order to avoid any seabed preparation. In addition, the project will develop a monitoring system to have a better understanding of loads applied to the structure for future foundations developments. This monitoring will allow to carry out a survey of the structural health for preventive maintenance which will contribute to improve reliability of the foundation. This report is the second deliverable in WP6 (Foundation Monitoring), namely D6.2 Sensor implemented and calibrated in proof-of-concept. RISE led the work with collaborative efforts from ALKIT. The proof-of-concept was proposed by RISE to enable the implementation of the proposed and developed monitoring system based on fibre optics in a representative reinforced concrete test object. This report covers the implementation in the proof-of-concept, the execution of experiment with mechanical loading on the test object, as well as the calibration of the given sensors and verification using secondary measuring techniques. The results show a complete characterization of the structure strain response along several loading cycles and the compatibility between the fibre optics-based sensors and the strain gauges validating the optical solution for structural monitoring. The system showed its capability for crack detection and also showed a good consistency of the measurements under repeated cycles. Lastly, a description of requirements and details for taking this proof-of-concept to the next phase of offshore monitoring of the concrete foundation is provided.

    Fulltekst (pdf)
    fulltext
  • 669.
    Williams Portal, Natalie
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Silva, Nelson
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Malaga, Katarina
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Mueller, Urs
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Billberg, Peter
    Consolis Strängbetong, Sweden.
    Durability study of textile fibre reinforcement2015Inngår i: Concrete 2015: Proceedings of the 27th Biennial National Conference of the Concrete Institute of Australia in conjunction with the 69th RILEM Week "Construction Innovations, Research into Practice", Institute of Australia , 2015, s. 408-413Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Conventional steel reinforced concrete is one of the most commonly used building materials,yet it has shortcomings in terms of weight, thick concrete covers, and durability namely corrosion of thereinforcement. Textile Reinforced Concrete (TRC), a combination of fine-grained concrete and noncorrosivefibre grids, has emerged as a promising alternative; corrosion is no longer an issue and muchthinner and light-weight elements can be designed. Although TRC has been expansively researched,unknowns pertaining to the long-term durability arise when attempting to implement such innovativebuilding materials. The aim of this article is to study the effect of accelerated aging on the tensile strengthof various textile fibre grids according to ISO 10406-1 [1]. Carbon, basalt and alkali-resistant (AR) glassfibre grids were immersed into high alkali environment and elevated temperature for 30 days. Directtensile tests were conducted before and after aging to observe the degree of stiffness and tensile strengthloss. After aging, the carbon fibre grids were marked by an increase in both tensile strength and stiffness,while AR-glass and basalt were degraded to the extent that tensile tests could not be conducted.Specimens were therefore exposed to alternative conditions to identify the governing degradation factor.

  • 670.
    Williams Portal, Natalie
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Zandi, Kamyab
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB, Betong & Berg.
    Malaga, Katarina
    RISE., SP – Sveriges Tekniska Forskningsinstitut, CBI Betonginstitutet AB.
    Wlasak, Lech
    Mostostal Warszawa SA, Poland.
    GFRP connectors in textile reinforced concrete sandwich elements2016Inngår i: IABSE Congress Stockholm 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment, IABSE c/o ETH Hönggerberg , 2016, s. 1336-1343Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper, both experimental and numerical methods are presented to gain an understanding of the structural behaviour related to a TRC sandwich panel with a glass fibre reinforced polymer (GFRP) plate connection system. Double shear tests were conducted on component-scale sandwich panels to characterize the available shear capacity provided by the connectors and panel configuration. Three-dimension (3D) non-linear Finite Element Analysis (NLFEA) was applied to develop a model for the design of TRC sandwich panels while focusing on the connectors. The experimental outcome of the shear tests was applied to validate the corresponding numerical model developed in this work. The need for further modifications to the design of the shear connectors or other parameters such as panel thickness can be established accordingly. This developed FE model can essentially be applied as a design tool to further predict the structural behaviour of the full-scale sandwich elements.

  • 671.
    Willstrand, Ola
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Karlsson, Peter
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Rosengren, Max
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    Brandt, Jonas
    RISE - Research Institutes of Sweden (2017-2019), Säkerhet och transport, Safety.
    New certification system for enhanced fire safety of vehicles2018Inngår i: Proceedings of 7th Transport Research Arena TRA 2018, 2018Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    RISE has initiated and developed a certification scheme for the vehicle industry that will enable manufacturers, operators and service centres (workshops) to certify their fire risk mitigation process. The fire risk management required in the certification is a key safety element, used to identify and evaluate fire hazards. For best results, it is important that manufacturers, operators and service centres are equally dedicated to solve the fire problem. Vehicle fire investigations reveal that design, production, operation and maintenance can all be responsible, however, most important is to ensure that information and experiences from fire incidents and identified fire hazards are linked to relevant personnel, practices, manuals, and quality procedures. The certification cannot guarantee the elimination of vehicle fires, but can ensure that manufacturers, operators and service centres will operate at the front line of vehicle fire safety engineering.

    Fulltekst (pdf)
    fulltext
  • 672.
    Wittgren, Hans Bertil
    et al.
    Sweden Water Research, Sweden.
    Arnell, Magnus
    RISE - Research Institutes of Sweden. Lunds universitet, Sweden.
    Berbeyer Cuevas, M.
    Gemit Solutions AB, Sweden.
    Bäckman, Jonas
    Gemit Solutions AB, Sweden.
    A tool to support upstream work2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Theupstream work at utilities can be facilitated by a tool for calculatingpollution loads. A web application for mapping sources and performing substanceflow analysis is being developed. It aims to support location of sources,planning of measurement campaigns and evaluation of specific measures.

  • 673.
    Wu, Pei-Yu
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Lund University, Sweden.
    Johansson, Tim
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Mangold, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Sandels, Claes
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden, Samhällsbyggnad. Lund University, Sweden.
    Estimating the probability distributions of radioactive concrete in the building stock using Bayesian networks2023Inngår i: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 222, artikkel-id 119812Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The undesirable legacy of radioactive concrete (blue concrete) in post-war dwellings contributes to increased indoor radon levels and health threats to occupants. Despite continuous decontamination efforts, blue concrete still remains in the Swedish building stock due to low traceability as the consequence of lacking systematic documentation in technical descriptions and drawings and resource-demanding large-scaled radiation screening. The paper aims to explore the predictive inference potential of learning Bayesian networks for evaluating the presence probability of blue concrete. By integrating blue concrete records from indoor radon measurements, pre-demolition audit inventories, and building registers, it is possible to estimate buildings with high probabilities of containing blue concrete and encode the dependent relationships between variables. The findings show that blue concrete is estimated to be present in more than 30% of existing buildings, more than the current expert assumptions of 18–20%. The probability of detecting blue concrete depends on the distance to historical blue concrete manufacturing plants, building class, and construction year, but it is independent of floor area and basements. Multifamily houses and buildings built between 1960 and 1968 or nearby manufacturing plants are more likely to contain blue concrete. Despite heuristic, the data-driven approach offers an overview of the extent and the probability distribution of blue concrete-prone buildings in the regional building stock. The paper contributes to method development for pattern identification for hazardous building materials, i.e., blue concrete, and the trained models can be used for risk-based inspection planning before renovation and selective demolition. © 2023 The Author(s)

  • 674.
    Wu, Pei-Yu
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Lund University, Sweden.
    Johansson, Tim
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Sandels, Claes
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Mangold, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden. Lund University, Sweden.
    Indoor radon interval prediction in the Swedish building stock using machine learning2023Inngår i: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 245, artikkel-id 110879Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Indoor radon represents a health hazard for occupants. However, the indoor radon measurement rate is low in Sweden because of no mandatory requirements. Measuring indoor radon on an urban scale is complicated, machine learning exploiting existing data for pattern identification provides a cost-efficient approach to estimate indoor radon exposure in the building stock. Extreme gradient boosting (XGBoost) models and deep neural network (DNN) models were developed based on indoor radon measurement records, property registers, and geogenic information. The XGBoost models showed promising results in predicting indoor radon intervals for different types of buildings with macro-F1 between 0.93 and 0.96, whereas the DNN models attained macro-F1 between 0.64 and 0.74. After that, the XGBoost models trained on the national indoor radon dataset were transferred to fit building registers in metropolitan regions to estimate the indoor radon intervals in non-measured and measured buildings by regions and building classes. By comparing the prediction results and the statistical summary of indoor radon intervals in measured buildings, the model uncertainty and validity were determined. The study ascertains the prediction performance of machine learning models in classifying indoor radon intervals and discusses the benefits and limitations of the data-driven approach. The research outcomes can assist preliminary large-scale indoor radon distribution estimation for relevant authorities and guide onsite measurements for prioritized building stock prone to indoor radon exposure. 

  • 675.
    Wu, Pei-Yu
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Lund University, Sweden.
    Mangold, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Sandels, Claes
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Johansson, Tim
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden. Lund University, Sweden.
    Modeling Artificial Neural Networks to Predict Asbestos-containing Materials in Residential Buildings2022Inngår i: IOP Conference Series: Earth and Environmental Science, Vol. 1122, artikkel-id 012050Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The presence of hazardous materials inhibits material circularity. The existing residential buildings are exposed to the risk of the unforeseen presence of asbestos-containing materials during the demolition or renovation process. Estimating the potential occurrence of contaminated building components can therefore facilitate semi-selective demolition and decontamination planning. The study aims to investigate the prediction possibility of seven frequently detected asbestos-containing materials by using artificial neural networks based on a hazardous material dataset from pre-demolition audit inventories and national building registers. Through iterative model evaluation and careful hyperparameter tuning, the prediction performance for each asbestos-containing material was benchmarked. A high level of accuracy was obtained for asbestos pipe insulation and ventilation channel, yet barely any patterns were found for asbestos floor mats. Artificial neural networks show potential for classifying specific asbestos components and can enhance the knowledge of their detection patterns. However, more quality data are needed to bring the models into practice for risk assessment for not yet inventoried residential buildings. The proposed screening approach for in situ asbestos-containing materials has high applicability for the quality assurance of recycled materials in circular value chains.

  • 676.
    Wu, Pei-Yu
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Lund University, Sweden.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden, Samhällsbyggnad. Lund University, Sweden.
    Mangold, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Bygg och fastighet.
    Sandels, Claes
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Johansson, T.
    KTH Royal Institute of tTechnology, Sweden.
    Tracing hazardous materials in registered records: A case study of demolished and renovated buildings in Gothenburg2021Inngår i: Journal of Physics, IOP Publishing Ltd , 2021, nr 1Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Hazardous materials encountered during building renovation or demolition processes not only result in uncertainty in cost estimation and the lead time but also hampers material recyclability and reuse. Therefore, the paper discusses the possibility of predicting the extent of the hazardous materials, including asbestos, PCB, mercury, and CFC, through data mining techniques based on registered records. Pre-demolition audits contain observation data that can be used as a sample for statistical prediction through careful processing. By developing an innovative approach of merging data from environmental inventories with building registers, the positive ratio of remaining hazardous materials in the Gothenburg building stock can be estimated. The study highlights the challenges of creating a training dataset by completing information from the existing environmental inventory, providing new insight into digital protocol development for enhancing material circularity. 

  • 677.
    Wu, Pei-Yu
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Lund University, Sweden.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden. Lund University, Sweden.
    Mangold, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Sandels, Claes
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Johansson, Tim
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation. KTH Royal Institute of Technology, Sweden.
    A Data-Driven Approach to Assess the Risk of Encountering Hazardous Materials in the Building Stock Based on Environmental Inventories2021Inngår i: Sustainability, E-ISSN 2071-1050, Vol. 13, nr 14, artikkel-id 7836Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The presence of hazardous materials hinders the circular economy in construction and demolition waste management. However, traditional environmental investigations are costly and time-consuming, and thus lead to limited adoption. To deal with these challenges, the study investigated the possibility of employing registered records as input data to achieve in situ hazardous building materials management at a large scale. Through characterizing the eligible building groups in question, the risk of unexpected cost and delay due to acute abatement could be mitigated. Merging the national building registers and the environmental inventory from renovated and demolished buildings in the City of Gothenburg, a training dataset was created for data validation and statistical operations. Four types of inventories were evaluated to identify the building groups with adequate data size and data quality. The observations’ representativeness was described by plotting the distribution of building features between the Gothenburg dataset and the training dataset. Evaluating the missing data and the positive detection rates affirmed that reports and protocols could locate hazardous materials in the building stock. The asbestos and polychlorinated biphenyl (PCB)-containing materials with high positive detection rates were highlighted and discussed. Moreover, the potential inventory types and building groups for future machine learning prediction were delineated through the cross-validation matrix. The novel study contributes to the method development for assessing the risk of residual hazardous materials in buildings.

  • 678.
    Wu, Pei-Yu
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Lund University, Sweden.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden. Lund University, Sweden.
    Sandels, Claes
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Mangold, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Machine Learning in Hazardous Building Material Management : Research Status and Applications2021Inngår i: Recent Progress in Materials, E-ISSN 2689-5846, Vol. 3, nr 2Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Assessment of the presence of hazardous materials in buildings is essential for improving material recyclability, increasing working safety, and lowering the risk of unforeseen cost and delay in demolition. In light of these aspects, machine learning has been viewed as a promising approach to complement environmental investigations and quantify the risk of finding hazardous materials in buildings. In view of the increasing number of related studies, this article aims to review the research status of hazardous material management and identify the potential applications of machine learning. Our exploratory study consists of a two-fold approach: science mapping and critical literature review. By evaluating the references acquired from a literature search and complementary materials, we have been able to pinpoint and discuss the research gaps and opportunities. While pilot research has been conducted in the identification of hazardous materials, source separation and collection, extensive adoption of the available machine learning methods was not found in this field. Our findings show that (1) quantification of asbestos-cement roofing is possible from the combination of remote sensing and machine learning algorithms, (2) characterization of buildings with asbestos-containing materials is progressive by using statistical methods, and (3) separation and collection of asbestos-containing wastes can be addressed with a hybrid of image processing and machine learning algorithms. Analysis from this study demonstrates the method applicability and provides an orientation to the future implementation of the European Union Construction and Demolition Waste Management Protocol. Furthermore, establishing a comprehensive environmental inventory database is a key to facilitating a transition toward hazard-free circular construction

    Fulltekst (pdf)
    fulltext
  • 679.
    Wu, Pei-Yu
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Lund University, Sweden.
    Sandels, Claes
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Johansson, Tim
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Mangold, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden. Lund University, Sweden.
    Machine learning models for the prediction of polychlorinated biphenyls and asbestos materials in buildings2023Inngår i: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 199, artikkel-id 107253Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hazardous materials in buildings cause project uncertainty concerning schedule and cost estimation, and hinder material recovery in renovation and demolition. The study aims to identify patterns and extent of polychlorinated biphenyls (PCBs) and asbestos materials in the Swedish building stock to assess their potential presence in pre-demolition audits. Statistics and machine learning pipelines were generated for four PCB and twelve asbestos components based on environmental inventories. The models succeeded in predicting most hazardous materials in residential buildings with a minimum average performance of 0.79, and 0.78 for some hazardous components in non-residential buildings. By employing the leader models to regional building registers, the probability of hazardous materials was estimated for non-inspected building stocks. The geospatial distribution of buildings prone to contamination was further predicted for Stockholm public housing to demonstrate the models’ application. The research outcomes contribute to a cost-efficient data-driven approach to evaluating comprehensive hazardous materials in existing buildings.

  • 680.
    Wu, Pei-Yu
    et al.
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik. Lund University, Sweden.
    Sandels, Claes
    RISE Research Institutes of Sweden, Säkerhet och transport, Mätteknik.
    Mjörnell, Kristina
    RISE Research Institutes of Sweden, Samhällsbyggnad. Lund University, Sweden.
    Mangold, Mikael
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Johansson, Tim
    RISE Research Institutes of Sweden, Samhällsbyggnad, Systemomställning och tjänsteinnovation.
    Predicting the presence of hazardous materials in buildings using machine learning2022Inngår i: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 213, artikkel-id 108894Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Identifying in situ hazardous materials can improve demolition waste recyclability and reduce project uncertainties concerning cost overrun and delay. With the attempt to characterize their detection patterns in buildings, the study investigates the prediction potential of machine learning techniques with hazardous waste inventories and building registers as input data. By matching, validating, and assuring the quality of empirical data, a hazardous material dataset for training, testing, and validation was created. The objectives of the explorative study are to highlight the challenges in machine learning pipeline development and verify two prediction hypotheses. Our findings show an average of 74% and 83% accuracy rates in predicting asbestos pipe insulation in multifamily houses and PCB joints or sealants in school buildings in two major Swedish cities Gothenburg and Stockholm. Similarly, 78% and 83% of recall rates were obtained for imbalanced classification. By correlating the training sample size and cross-validation accuracy, the bias and variance issues were assessed in learning curves. In general, the models perform well on the limited dataset, yet collecting more training data can improve the model's generalizability to other building stocks, meanwhile decreasing the chance of overfitting. Furthermore, the average impact on the model output magnitude of each feature was illustrated. The proposed applied machine learning approach is promising for in situ hazardous material management and could support decision-making regarding risk evaluation in selective demolition work. © 2022 The Author(s)

  • 681.
    Wu, Yaoxing
    et al.
    Virginia Tech, US.
    Cox, Steven S.
    Virginia Tech, US.
    Xu, Ying
    University of Texas at Austin, US.
    Liang, Yirui
    University of Texas at Austin, US.
    Won, Doyun
    National Research Council Canada, Canada.
    Liu, Xiaoyu
    United States Environmental Protection Agency, US.
    Clausen, Per A.
    National Research Centre for the Working Environment, Denmark.
    Rosell, Lars
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Benning, Jennifer L.
    South Dakota School of Mines and Technology, US.
    Zhang, Yinping
    Tsinghua University, China.
    Little, John C.
    Virginia Tech, US.
    A reference method for measuring emissions of SVOCs in small chambers2016Inngår i: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 95, s. 126-132Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Semi-volatile organic compounds (SVOCs) are indoor air pollutants that may have significant adverse effects on human health. Although emissions of volatile chemicals from building materials and consumer products are usually characterized in small chambers, few chamber studies have been conducted for SVOCs due to the challenges associated with analysis and the lack of validation procedures. There is an urgent need for a reliable and accurate chamber test method to verify these measurements. A reference method employing a specially-designed chamber has been developed and is undergoing extensive evaluation. A pilot inter-laboratory study (ILS) has been conducted with six laboratories performing chamber tests under identical conditions for di-2-ethylhexyl phthalate (DEHP). Results from this study showed inter-laboratory variations of 24% for DEHP emission rates, with closer agreement observed among intra-laboratory measurements for most of the participating laboratories. A mechanistic emission model fits well to the measured concentration profiles, demonstrating the feasibility of the proposed reference method to independently assess laboratory performance and validate SVOC emission tests.

  • 682.
    Xu, Dai
    et al.
    University of Edinburgh, UK.
    Welch, Stephen
    University of Edinburgh, UK.
    Rush, David
    University of Edinburgh, UK.
    Charlier, Marion
    ArcelorMittal, Sweden.
    Anderson, Johan
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    CHARACTERISING NATURAL FIRES IN LARGE COMPARTMENTS – REVISITING AN EARLY TRAVELLING FIRE TEST (BST/FRS 1993) WITH CFD2019Inngår i: Interflam 2019, proceedings / [ed] Stephen Grayson, Interscience Communications, 2019, Vol. 15, s. 2111-Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a careful assessment of fire conditions in a long enclosure, open only at one end, which contained a regularly spaced timber crib fire load and is dominated by under-ventilated combustion. Though the geometrical arrangement, with fully enclosed side walls, differs from many more recent “travelling fire” tests, the essential fire behaviour shows a very clear progression of the main burning zone, driven by a combination of fire spread, ventilation and fuel burn out. By contrast many other travelling fire tests have been designed to be fuel-controlled, in much more open structures. Moreover, due to the enclosed nature of the test, it was observed to result in very high temperatures in the protected and unprotected steel beam members, especially during the phase when the fire travelled back from the opening to the ignition location at the rear of the compartment. The investigated test in this paper is Test number 2, which is one of nine tests carried out at the BRE Cardington laboratory in the UK, led by British Steel Technical (BST) and hosted by the Fire Research Station (FRS).CFD modelling, with NIST’s Fire Dynamics Simulator (FDS), is invoked to assist in exploration and interpretation of the test results, and to evaluate model capabilities for this complex fire scenario. For simplicity, instead of modelling the complex pyrolysis and combustion of timber on a stick-by-stick basis, the entire wood cribs are represented in the FDS model as single objects. Thus ignition and burning are represented in a simplified manner at the scale of the individual crib faces, with idealised mass loss curves derived from measurements in selected rows. Though tied to empirical mass loss, the model is stretched in representing heavily under-ventilated conditions occurring in certain domains. Despite these simplifications and challenges the model does prove capable of representing the qualitative behaviours to a satisfactory level. In particular, with appropriate parameter choice for reaction-to-fire properties, the FDS models are able to represent the fire spread rates for the two distinct stages of the fire: the fire travelling from rear to the front of the compartment in search of oxygen; and the fire travelling back from the opening to the rear as fuel is consumed. The results suggest the potential value of such simplified representations of cribs in FDS for travelling fire scenarios.In the calibrated model, the magnitude of the thermocouple (TC) temperatures at three locations (ignition location, centre location, and opening location) shows generally good agreement between the FDS model and the test at the stage when the fire travels to the opening. However, significantly higher discrepancy appears at the stage when the fire travels back. In addition to the highly simplified representation of crib burning, another likely reason for the latter may be the malfunction of the mass loss measurement in several wood cribs at this stage, which led to significant uncertainties in prescribed burning rates. Another large source of uncertainty relates to residual heat in compartment boundaries and fuel embers, the latter not being easy to represent in CFD models. These results suggest avenues to explore in future model development.

  • 683.
    Yang, A.
    et al.
    SINTEF, Norway.
    Aamodt, A.
    SINTEF, Norway.
    Samuelsen, P. H.
    Oslobygg KF, Norway.
    Olsø, B. G.
    SINTEF, Norway.
    Haukø, A. -M
    SINTEF, Norway.
    Meraner, Christoph
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Fire safety of ventilation systems and fire incidence reports in Norwegian schools2022Inngår i: ROOMVENT 2022, EDP Sciences , 2022Konferansepaper (Fagfellevurdert)
    Abstract [en]

    School fires are causes of concern in many countries. Although most of these fires are minor in terms of heat release rate, the amount of smoke produced can be substantial and cause significant damage beyond the room of origin. Currently, Norwegian schools have a wide spread of different ventilation strategies and systems, and building owners struggle with how to test, maintain and keep them fire safe. A systematic survey of fire incidences and ventilation strategies in schools for three municipalities in Norway was done to gain better insights into fire safety in schools. The results indicated that the place of origin is often in locker rooms/toilets, kitchen, or outdoors, and the fires were usually deliberately set. For non-arson fires, electrical failure was the most common cause. The majority of the fire incidences were small but would often result in smoke damage and spread of soot in the building, leading to high restoration costs for the local municipality. A lack of documentation of the fire safety and the function of the ventilation system was also identified, indicating a need for improved routines and systems for registering fire incidences and documentation of the technical systems. © The Authors, published by EDP Sciences. This is an open access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/)

  • 684.
    Yang, Xiaoxue
    et al.
    Tongji University, China.
    Zou, Yajie
    Tongji University, China.
    Zhang, Hao
    Tongji University, China.
    Qu, Xiaobo
    Tsinghua University, China.
    Chen, Lei
    RISE Research Institutes of Sweden, Digitala system, Mobilitet och system.
    Improved deep reinforcement learning for car-following decision-making2023Inngår i: Physica A: Statistical Mechanics and its Applications, ISSN 0378-4371, E-ISSN 1873-2119, Vol. 624, artikkel-id 128912Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Accuracy improvement of Car-following (CF) model has attracted much attention in recent years. Although a few studies incorporate deep reinforcement learning (DRL) to describe CF behaviors, proper design of reward function is still an intractable problem. This study improves the deep deterministic policy gradient (DDPG) car-following model with stacked denoising autoencoders (SDAE), and proposes a data-driven reward representation function, which quantifies the implicit interaction between ego vehicle and preceding vehicle in car-following process. The experimental results demonstrate that DDPG-SDAE model has superior ability of imitating driving behavior: (1) validating effectiveness of the reward representation method with low deviation of trajectory; (2) demonstrating generalization ability on two different trajectory datasets (HighD and SPMD); (3) adapting to three traffic scenarios clustered by a dynamic time warping distance based k-medoids method. Compared with Recurrent Neural Networks (RNN) and intelligent driver model (IDM), DDPG-SDAE model shows better performance on the deviation of speed and relative distance. This study demonstrates superiority of a novel reward extraction method fusing SDAE into DDPG algorithm and provides inspiration for developing driving decision-making model. © 2023 Elsevier B.V.

  • 685.
    Yao, Y.
    et al.
    China University of Mining and Technology, China.
    Wang, J.
    China University of Mining and Technology, China.
    Jiang, Lei
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Wu, B.
    China University of Mining and Technology, China.
    Qu, B.
    China University of Mining and Technology, China.
    Numerical study on fire behavior and temperature distribution in a blind roadway with different sealing situations2023Inngår i: Environmental Science and Pollution Research, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 30, s. 36967-36978Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Blind roadways have only one portal which connects with other types of mine roadways. Sealing the fire area in a blind roadway is an effective method of disaster relief in a mine. To understand the effect of sealing ratio and sealing distance on fire behavior, Fire Dynamics Simulator (FDS 6.6) was used to study blind roadway fires with different fire scenarios. Results indicate that the smoke flow velocity increases significantly with the increase of sealing distance. The fire in the blind roadway is ventilation-controlled. When the sealing ratio reaches 80%, the fire self-extinguishes completely. Otherwise, the fire experiences an extinguishing-reburning cycle periodically. Besides, an empirical model is proposed to predict the downstream temperature distribution beneath the ceiling in the region from fire source to sealing position. The predictions by the proposed model comply well with the simulation and experimental results from our and others’ studies. This study provides new insights into the sealing strategies in blind roadway fires, and the outcomes of the current study are of guiding significance for the fire rescue in the blind roadways or similar structures. © 2022, The Author(s)

  • 686.
    Yao, Yongzheng
    RISE - Research Institutes of Sweden, Säkerhet och transport, Safety.
    Fire Behaviors and smoke transportation law of tunnel fires under confined portal boundaries2019Rapport (Annet vitenskapelig)
    Abstract [en]

    An increasing number of tunnels have been built around the world. They play an important role to relieve traffic congestions and facilitate goods transportation. However, in the event of a fire in tunnels, the consequences can be serious due to its narrow-long structure. The previous studies about tunnel fire dynamics and mitigation measures are mostly based on good ventilation conditions in tunnels, such as longitudinal ventilation and natural ventilation with the premise that a tunnel has two open portals. However, the studies about the characteristics of tunnel fires under confined portal boundaries with complete or incomplete sealing at both portals are rare. Typical fire scenarios can appear in a subway train, a building corridor, an underground utility tunnel, a mining tunnel, a tunnel during construction and the application of sealing tunnel portals for fighting large tunnel fires and so on. The knowledge of tunnel fire dynamics for tunnels under good ventilation conditions is probably not applicable to the scenarios of tunnel fires under confined portal boundaries. Conducting the studies of tunnel fires under confined portal boundaries is of great significance for better understanding the characteristics of this type of tunnel fires and developing tunnel fire mitigation measures. Therefore, by combining model-scale tunnel experiments and theoretical analyses, this thesis studies the fire behaviors and smoke transportation law of tunnel fires under confined portal boundaries. The main research contents include:

    1.Scaling effects of mass loss rate per unit area (MLRPUA) for well-ventilated pool fires are studied by summarizing large amounts of experimental data from the literature together with theoretical analyses. As a further extension of tunnel fire similarity theory, it provides the basis and reference for later model/medium-scale tunnel experiments. Results show that when a small-scale pool fire (D<1 m) occurs in the open, increasing wind velocity tends to increase the MLRPUA, especially for pools with D<0.2 m. This is because the ventilation significantly increases the conductive and convective heat feedbacks (leading role). But when small-scale pool fires occurs in tunnels with a short distance between the pool surface and ceiling (Hef/D<3), the radiative heat feedback from the tunnel ceiling is probably dominating, leading to a much higher MLRPUA than that in the free burn. When subjected to longitudinal flows, the MLRPUA decreases due to the reduced radiation effect from the ceiling. With the increase of pool diameter, the influence of wind on the MLRPUA decreases gradually, no matter whether the pool occurs in the open or in a tunnel. Finally, when the pool diameter exceeds 1 m, the radiation from flame itself is probably predominant. The MLRPUA is not significantly affected by increasing wind velocity and most likely fluctuates within 30% for a wide range of wind velocities based on the test data collected.

    2.The flame behaviors and the maximum gas temperature rise beneath the ceiling in an enclosed tunnel are studied using a model-scale tunnel. Results show that when a fire (small fire) is not located at the tunnel center, the flame inclines towards the closer tunnel end due to the asymmetric flow field on both sides of the flame. The flame inclination angle keeps increasing when the fire is moving away from the tunnel center. Furthermore, when a fire is in Region I (0< ≤0.64), the maximum gas temperature rise decreases with the increasing dimensionless fire distance due to the increasing flame inclination angle. When a fire is in Region II (0.64< <1), the maximum gas temperature rise increases with the increasing dimensionless fire distance due to the heat feedback of returned hot smoke bounced from the end wall. By introducing a concept of equivalent ventilation velocity based on the flame inclination mechanism, a prediction model of maximum gas temperature rise beneath the ceiling in Region I is developed. Beyond that, an extra correction factor is proposed to the improved model in Region II with a consideration of heat feedback of returned hot smoke bounced from the end wall. Besides, further dimensional analysis indicates that the normalized maximum gas temperature rise follows an exponential attenuation law with the dimensionless fire distance.

    3.The coupling control effects of sealing ratio and initial sealing time on the fire development (large fire) are studied using a model-scale tunnel. Results show that sealing tunnel portals can decrease the mass loss rate of fuel and gas temperature inside the tunnel, no matter whether the sealing is complete or incomplete. The earlier the initial sealing time is, the better the fire can be controlled. For the incomplete sealing, when the sealing is implemented during the violent burning stage, the sealing not only does not limit the fire growth but also exacerbates the tunnel fire, producing an extremely high CO concentration at tunnel portals and a longer ceiling flame jet. This will result in a huge threat to the rescue service at tunnel portals. Besides, if the tunnel portals are sealed incompletely, it will leave a small area for the exchange of smoke and air. The smoke will not continue to spread horizontally after leaving the tunnel portals under the action of inertial forces. In order to maintain the combustion of fuel, the fresh air from external environment flows into the tunnel vigorously and quickly from the gap and then uplifts the smoke out of the tunnel portals, which is also an important phenomenon for firefighters and needs to draw their attentions.

    4.The critical conditions for the occurrence of under-ventilated tunnel fires and the combustion mechanisms under confined portal boundaries are studied by using both model-scale and medium-scale tunnels. Results show that the critical equivalence ratio for the occurrence of under-ventilated tunnel fires is within 0.53 - 0.6, which is less than the theoretical value of 1. This is related to the occurrence of vitiation, consequently reducing the level of oxygen around the flame by diluting the O2 concentration. The low ventilation rate and vitiation result in a low O2 volume fraction around the flame, and then the MLRPUA starts to decrease and at the same time the air mass flow into the tunnel becomes almost constant. Also, an oscillating MLRPUA and lifted flame are observed in the model-scale tests. Consequently, the ventilation rate approaches and even reaches the amount required for complete combustion of vaporized fuel. This means that the insufficient combustion in early under-ventilated tunnel fires has converted to sufficient combustion (from the perspective of the change of equivalence ratio, the fire has converted from under-ventilated to well-ventilated). As a result, no significant increase in CO production in under-ventilated fires is observed in both test series.

    5.The critical conditions for the occurrence of self-extinguishment and influencing factors in under-ventilated tunnel fires are studied in a model-scale tunnel during construction. The tunnel consists of an inclined access tunnel and a horizontal main tunnel. Results show that when a fire is in the horizontal main tunnel, the critical equivalence ratio for self-extinguishment is within 0.28 - 1.38 for the propane gas burner and 1.11 - 3.6 for the fibre board soaked with heptane. The difference is related to the burning behavior of the different fuels used. Moreover, the critical O2 volume fraction is about within 12 - 15% when the fires self-extinguish. When a fire is at the closed end of the horizontal main tunnel, the stratification of smoke is destroyed after hitting the closed end, and then the smoke seems to spread over the entire cross section of the tunnel. The smoke spread velocity is proportional to the ventilation rate. However, when a fire occurs at the closed end of the inclined access tunnel, the fire does not self-extinguish, even when the ventilation rate is 0 m3/s. The corresponding smoke spread velocity is higher than that in the horizontal main tunnel. This is probably related to the increasing component of buoyancy in the longitudinal direction in the inclined access tunnel. Besides, no insignificant vitiation behind the fire is found. These two characteristics in the inclined access tunnel increase the temperature of smoke flowing out of the tunnel portal and in turn promote the natural ventilation and increase the O2 volume fraction.

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  • 687.
    Yarahmadi, Nazdaneh
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Sällström, Jan H
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    IMPROVED MAINTENANCE STRATEGIES FOR DISTRICT HEATING PIPE-LINES2014Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The main objective of this work was to establish factsand tools, which could help us to obtain and predictpresent and future technical status of pre-insulatedbonded district heating pipes in operation. In order tosimulate ageing of polyurethane (PUR) insulation anaccelerated thermal ageing method was used.Accelerated ageing was performed by applying threedifferent elevated temperatures to the service pipes.The effect of the diffusion of oxygen through the casingwas examined by ageing district heating pipes with twodifferent thicknesses of the casing pipes.The evaluation of the technical status of the pipes afterartificial or natural ageing was done by measuring theshear strength (adhesion) between the PUR foam andthe steel service pipe. The tangential shear strengthtest method was mainly used for evaluation of thestatus of the pipes. The SP plug test method, which isa cheaper and more practical method in the field, wasalso used, and the results were compared with thosefrom the tangential shear strength test method.In the framework for improved maintenance strategies,the failure mechanism was considered as loss ofadhesion between polyurethane and the service pipe.The deterioration of the adhesion was assumed to be athermo-oxidative process governed by an Arrheniusrelationship. A model of how the development of faultsrelated to adhesion and costs of heat losses in a districtheating distribution network was sketched.

  • 688.
    Yarahmadi, Nazdaneh
    et al.
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Sällström, JH
    RISE., SP – Sveriges Tekniska Forskningsinstitut.
    Improved maintenance strategies for district heating pipe lines2014Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    The main objective of this work was to establish factsand tools, which could help us to obtain and predictpresent and future technical status of pre-insulatedbonded district heating pipes in operation. In order tosimulate ageing of polyurethane (PUR) insulation anaccelerated thermal ageing method was used.Accelerated ageing was performed by applying threedifferent elevated temperatures to the service pipes.The effect of the diffusion of oxygen through the casingwas examined by ageing district heating pipes with twodifferent thicknesses of the casing pipes.The evaluation of the technical status of the pipes afterartificial or natural ageing was done by measuring theshear strength (adhesion) between the PUR foam andthe steel service pipe. The tangential shear strengthtest method was mainly used for evaluation of thestatus of the pipes. The SP plug test method, which isa cheaper and more practical method in the field, wasalso used, and the results were compared with thosefrom the tangential shear strength test method.In the framework for improved maintenance strategies,the failure mechanism was considered as loss ofadhesion between polyurethane and the service pipe.The deterioration of the adhesion was assumed to be athermo-oxidative process governed by an Arrheniusrelationship. A model of how the development of faultsrelated to adhesion and costs of heat losses in a districtheating distribution network was sketched.

  • 689.
    Yarahmadi, Nazdaneh
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, Energi och cirkulär ekonomi.
    Vega, Alberto
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, Energi och cirkulär ekonomi.
    Jakubowicz, Ignacy
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, Energi och cirkulär ekonomi.
    Determination of essential parameters influencing service life time of polyurethane insulation in district heating pipes2017Inngår i: Energy Procedia, Elsevier Ltd , 2017, s. 320-323Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Pre-insulated district heating pipes (DHP) have been in use during the last forty years. Many improvements and development have been done in the system. However, life-time prediction is still an uncertain issue. This paper is a part of a bigger project with the objective to determine mechanisms related to the deterioration of the mechanical and insulation properties of pre-insulated heating pipes as a result of ageing. The focus in this project is on degradation mechanisms of the PUR material at high temperatures. In this paper some results of the two types of exposure are presented. The first type comprises a condition where the new pipes are subjected to accelerated ageing at three different temperatures. The second type comprises condition, when the PUR material itself is aged in different atmospheres in order to identify different degradation mechanisms. The chosen ageing temperatures in the first condition were 130°C, (close to the supply temperature), 150°C and 170°C, (accelerated ageing temperature in EN 253 [1]). Changes in thermal insulation and the adhesion force between the PUR and the steel pipe were evaluated using the transient plane source (TPS) technique and the SP plug method respectively. The results of ageing show that the degradation of PUR is a multi-stage process composed of a rapid change in properties followed by a plateau phase which changes later to a gradual deterioration of the properties. The results of the PUR material exposure at 150°C in air and in nitrogen showed significant differences in the degradation characteristics between the two environments as were revealed by DSC and FTIR methods. © 2017 The Authors. Published by Elsevier Ltd.

  • 690.
    Yarahmadi, Nazdaneh
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, Energi och cirkulär ekonomi.
    Vega, Alberto
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, Energi och cirkulär ekonomi.
    Jakubowicz, Ignacy
    RISE - Research Institutes of Sweden (2017-2019), Biovetenskap och material, Kemi och material.
    Livslängd för fjärrvärmerör: Fas 1 - Nedbrytningsmekanismer2017Rapport (Annet vitenskapelig)
    Abstract [sv]

    Dagens standard för prefabricerade fjärrvärmerör SS-EN253 innehåller olika testmetoder och krav där ett av de viktigaste är kravet på livslängd på minst 30 år vid en kontinuerlig driftstemperatur på 120 °C. Bestämningen av tekniska livslängden är baserad på mätningar av förändringar i skjuvhållfastheten efter accelererad termisk åldring. Den beräknade livslängden för ett fjärrvärmerör är baserad på extrapolering med hjälp av Arrhenius ekvation. Det finns en stor enighet kring uppfattningen att Arrhenius modellen inte ger en god överensstämmelse med de observerade åldringsdata och att det följaktligen saknas tillförlitliga metoder för livslängdsbestämning av fjärrvärmerör. Trots många forskningsrapporter finns det fortfarande skilda teorier om hur snabbt PUR-isoleringar bryts ner och vilka nedbrytningsmekanismer som dominerar. Syftet med det här projektet är att kartlägga de komplicerade sambanden och förstå vilka nedbrytningsprocesser som dominerar under olika betingelser och utifrån denna kunskap utveckla tillförlitliga metoder för livslängdsprediktering.

    Allt testmaterial utgjordes i denna studie av polyuretan (PUR) cellplastisolering som togs ut från nytillverkade fjärrvärmerör. Accelererad åldring genomfördes i luft och i kväveatmosfär vid 150 °C för upp till 8 veckor. Det visade sig att exponering i kväveatmosfär inte orsakar någon mätbar förändring av egenskaper. En motsvarande åldring i luft orsakar däremot stora förändringar i både dimensioner, viktförlust och färg. IR (infraröd) analys kunde också bekräfta att materialet bryts ner genom termo-oxidativa processer. Termo-oxidativ nedbrytning syns också i analyser av cellgassammansättningen. Materialet efter åldring i luft innehåller betydligt mindre halt cyklopentan samtidigt som fyra nya flyktiga ämnen kunde detekteras. Trots alla indikationer på materialets termo-oxidativa nedbrytning har böjhållfastheten inte förändrats hos materialet. Detta måste utredas vidare för att kunna förklara mekanismer bakom resultatet.

    Förutom beständighetsstudier av PUR materialet genomfördes långtidsåldring av fjärrvärmerör vid olika temperaturer. Resultaten av skjuvhållfasthet mätningar indikerar att det åtminstone finns tre olika faser i nedbrytningsprocessen. Initialt sjunker hållfastheten troligen på grund av fysikaliska effekter orsakade av de höga temperaturerna. Därefter ökar skjuvhållfastheten troligen beroende på sidoreaktioner och fortsatt tvärbindning. Det tredje steget är en termo-oxidativ nedbrytning som såsmåningom leder till förlust av vidhäftningen. Även värmeledningsförmågan ökar betydligt som ett resultat av nedbrytningsprocesser. Det finns behov av ytterligare forskning för att kunna föreslå en ny modell för livslängdsberäkningar baserade på experimentella resultat.

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  • 691.
    Ylmen, Peter
    RISE Research Institutes of Sweden, Samhällsbyggnad. Lund University, Sweden: Built Environment RISE, Sweden.
    Managing Uncertainty in Environmental and Cost Life Cycle Studies of Building Design2020Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    In order to mitigate global warming and address other pertinent environmental issues, it is important to reduce the environmental impact from the building stock. Emissions can be large for both operational energy consumption and production of materials. It is therefore important to find building design solutions that consider production, operation and maintenance in order to minimise the climate impact of a building during its entire lifetime. At the same time, the production of buildings has to be cost-efficient. In the design of buildings, both environmental impact and cost must be evaluated in order to make well-supported decisions.

     

    There are many uncertainties in the design phase of buildings. This study explored the uncertainties that occur when a life cycle perspective is adopted in building design decisions and developed an approach to manage them. Addressed issues were secondary effects of design changes, material data gaps and how subjective choices and parameter uncertainties can be managed in conjunction. This was done by developing the Effect and Consequences Evaluation (ECE) method and the Decision Choices Procedure (DCP), which were combined into a general approach. The presented approach will provide a structured means to set up system boundaries and manage uncertainties when life cycle studies are used as decision support for optimising building design. Several case studies were carried out to penetrate specific issues, and the final approach was demonstrated with a case study of selecting optimal insulation thickness when designing the building envelope.

     

    The results can be used to support decisions on where and how to effectively make improvements when subjective choices and parameter uncertainties are considered in the study. This will facilitate decisions on different building design solutions so that the option with the lowest total environmental impact and a reasonable cost can be chosen.

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  • 692.
    Ylmen, Peter
    et al.
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Byggteknik. Lund University, Sweden.
    Mjörnell, Kristina
    RISE - Research Institutes of Sweden.
    Berlin, Johanna
    RISE - Research Institutes of Sweden, Samhällsbyggnad, Energi och cirkulär ekonomi.
    Arfvidsson, J.
    Lund University, Sweden.
    The influence of secondary effects on global warming and cost optimization of insulation in the building envelope2017Inngår i: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 118, s. 174-183Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The relative environmental impact from the building construction phase is increasing compared to the operation phase for new buildings. Therefore, it is important to consider the complete environmental life cycle of energy improvement measures. Many advanced optimization methods have been developed in recent years to assess building life cycle impact. However, these previous studies have not fully addressed the secondary effects, in other words, indirect effects outside the actual design option. This may lead to conclusions of optimization studies based on misleading calculation results. The main purpose this study was to highlight the relevance of including secondary effects in optimization of building design with respect to global warming potential and cost. This was done by conducting a parameter study of the building envelope insulation thickness with regard to global warming potential and life cycle costs, while considering secondary effects induced by the different design options. Findings from this study show that secondary effects influence the system boundary, algorithm architecture, results and the final conclusions of optimal building design. Omitting secondary effects can thus lead to incorrect decision on optimal solutions with regard to global warming potential and life cycle cost. Therefore, it is therefore important to take them into consideration when performing optimization studies of building design options.

  • 693.
    Ylmen, Peter
    et al.
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, Byggteknik.
    Peñaloza, Diego
    IVL Swedish Environmental Research Institute, Sweden.
    Mjörnell, Kristina
    RISE - Research Institutes of Sweden (2017-2019), Samhällsbyggnad, Byggteknik.
    Life Cycle Assessment of an Office Building Based on Site-Specific Data2019Inngår i: Energies, E-ISSN 1996-1073, Vol. 12, nr 13, artikkel-id 2588Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Life cycle assessment (LCA) is an established method to assess the various environmental impacts associated with all the stages of a building. The goal of this project was to calculate the environmental releases for a whole office building and investigate the contribution in terms of environmental impact for different parts of the building, as well as the impact from different stages of the life cycle. The construction process was followed up during production and the contractors provided real-time data on the input required in terms of building products, transport, machinery, energy use, etc. The results are presented for five environmental impact categories and, as expected, materials that constitute the main mass of the building and the energy used during operation contribute the largest share of environmental impact. It is usually difficult to evaluate the environmental impact of the materials in technical installations due to the lack of data. However, in this study, the data were provided by the contractors directly involved in the construction and can, therefore, be considered highly reliable. The results show that materials for installations have a significant environmental impact for four of the environmental impact categories studied, which is a noteworthy finding.

  • 694.
    Ylmen, Peter
    et al.
    RISE Research Institutes of Sweden, Samhällsbyggnad, Bygg och fastighet.
    Schade, Jutta
    RISE Research Institutes of Sweden, Samhällsbyggnad, Bygg och fastighet.
    Termisk inomhuskomfort vid värmeböljor2021Rapport (Annet vitenskapelig)
    Abstract [en]

    Climate change with more frequent and longer heat waves in the future will be a challenge for the cities in Sweden. With more frequent heat waves the demand for mechanical cooling will increase. This will lead to higher energy consumption with the consequence that the emissions of greenhouse gases increase and affect climate change even further. To avoid thermal discomfort during the summers the design and constructions in the building have central roles. Sun protecting measures like awnings and shadings as well as window airing can have a large impact on the indoor temperature. This study investigates how different climates affect the indoor temperature in buildings and the results illustrate the problems with thermal comfort that can arise. Additionally, long lasting technical solutions to mitigate high indoor temperatures during heat waves were evaluated. The results show how different prerequisites, as well as common solutions, for buildings affect the thermal comfort. They also identify the importance of a holistic system view of the building during the design so that the thermal comfort aspects are considered together with energy improvement measures.

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  • 695.
    Yu Faxér, Anne
    RISE - Research Institutes of Sweden (2017-2019), ICT, Viktoria.
    Cykelstaden – El-assisterade lastcyklars framtida roll2018Rapport (Annet vitenskapelig)
    Abstract [sv]

    Projektet visar att ellastcyklar med framgång kan användas i kommunala förvaltningar, där de kan minska klimatpåverkan och energianvändning genom att ersätta bil men även innebära fördelar för arbetsmiljön. Det har visats att ellastcyklar passar bättre för vissa typer av verksamheter än för andra, och att införandet inte är helt bekymmersfritt. För förvaltningar som jobbar med logistik kan ellastcyklar passa mycket bra, men där behöver införandet få ta tid, så att användarna kan anpassa scheman och rutter efter det nya fordonet. För verksamheter som mest har behov av persontransport är det viktigt att identifiera vilka resor där ellastcykeln kan göra nytta.

    Projektet har studerat en ny typ av ellastcykel med väderskydd, som använts i fyra förvaltningar inom Göteborgs stad. Målet var att identifiera vilken potential detta fordon har att ersätta tjänsteresor med bil. Genom intervjuer med användare, planerare och tillverkare har projektet kunnat belysa många aspekter av att införa och använda ellastcykel i dagens transportsystem. I slutet av projektet genomfördes en workshop, där användare, planerare, tillverkare och forskare tillsammans diskuterade lösningar för att främja ellastcyklar.

    Det skulle vara värdefullt att följa upp projektet med ytterligare forskning kring hur ellastcyklar passar för olika verksamheter och situationer. Därigenom skulle en guide för hur och var kommuner och andra organisationer kan införa ellastcyklar kunna utvecklas. Detta skulle vara viktigt för att främja ökad användning av ellastcyklar och för att se till att införandet sker så effektivt och smärtfritt som möjligt.

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  • 696.
    Zackrisson, Mats
    et al.
    RISE Research Institutes of Sweden, Material och produktion, Metodik för produktframtagning.
    Tidbeck, Björn
    RISE Research Institutes of Sweden, Material och produktion, Korrosion.
    Stam, Björn
    ST Control, Sweden.
    Refurbishment of hot dip galvanized products – environmental impacts in a life cycle perspective2021Rapport (Annet vitenskapelig)
    Abstract [en]

    This report contains a life cycle assessment of hot dip galvanized steel and refurbishment methods for hot dip galvanized steel. The purpose of the report is to investigate the environmental impact of different refurbishment methods and to compare the environmental impact of replacing hot-dip galvanized steel structures with maintenance of the corrosion protection of hot-dip galvanized steel structures. The analysis was carried out within the framework of an assignment performed for RISE KIMAB by Mats Zackrisson at RISE IVF, in the project Optimal maintenance of hot-dip galvanized products. Paint manufacturers, painting contractors, painting inspectors and researchers at RISE KIMAB have all contributed data and knowledge to the study. The results show that the pre-treatment and the zinc can give significant impacts for the refurbishment options. From a climate perspective, the results indicate that the refurbishment options need only prolong the life with 1-6 years, which, compared to the expected life extension 30 years indicates a large climate impact reduction potential with any of the refurbishment options. From an ozone formation perspective, the results indicate that the refurbishment options need to prolong the life with 3-33 years, which, compared to the expected life extension 30 years indicates that the right choice of refurbishment option is crucial in order to achieve potential ozone impact reductions with refurbishment. The practical corrosion tests carried out in the project will give more definite answers. The difference in potential impact between the refurbishment options should not be taken as absolute, since the information was mostly gathered from open sources, like safety data sheets and product information sheets. Nevertheless, the low (inherent) ozone formation impacts associated with the waterborne zinc silicate is worth mentioning, as well as Induraguard 9200´s environmentally benign pre-treatment (wire brushing). The study focuses on 8 mm thick steel structures. The thicker and heavier object, the more is, in general, to gain by refurbishing instead of replacing with new infrastructure object.

    Fulltekst (pdf)
    fulltext
  • 697.
    Zawadowska, Aleksandra
    et al.
    RISE Research Institutes of Sweden.
    Giuliani, Luisa
    DTU Technical University of Denmark, Denmark.
    Dahl Hertz, Kristian
    DTU Technical University of Denmark, Denmark.
    Experimental study on the mechanical properties of fire exposed concrete2021Inngår i: Safety Science, ISSN 0925-7535, E-ISSN 1879-1042, Vol. 142, artikkel-id 105357Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A number of fire-induced collapses of concrete buildings has been reported over the last decades, indicating the need of a better understanding of behaviour of concrete during fire events and of reassessing models recommended by currently used standards for structural fire safety design.This study investigates the mechanical properties of concrete exposed to elevated temperatures. After carrying out preliminary compression and temperature tests, ductility and strength of cylindrical concrete specimens at high temperature were measured in transient and non-transient tests. In transient tests, the specimens were preloaded to a certain stress level and heated up to failure. In non-transient tests, specimens were first heated up to a set temperature and then compressed until failure.The results are presented in terms of stress-strain relationships and critical temperatures. Such results are compared with different concrete models found in literature, as well as with the values recommended by the Eurocode (EN, 2004). The analysis of the strength degradation in non-transient tests indicated that strength values recommended by the Eurocode may not be conservative. Similar conclusions were drawn regarding the strain at peak stress, where the values suggested by Eurocode were found to be unrealistic from the design point of view. Based on the comparison of results obtained in transient and non-transient test, more conservative values of the strength were observed in transient tests. More tests are needed, in order to confirm these conclusions on larger data set. 

  • 698.
    Zhao, Shengzhong
    et al.
    Shandong Jianzhu University, China.
    Yang, Haoran
    Shandong Jianzhu University, China.
    Li, Ying Zhen
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Ingason, Haukur
    RISE Research Institutes of Sweden, Säkerhet och transport, Brand och Säkerhet.
    Liu, Fang
    Chongqing University, China.
    Theoretical and numerical study on smoke descent during tunnel fires under natural ventilation condition2023Inngår i: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 142, artikkel-id 105414Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The smoke stratification and the smoke descent along a tunnel are of the utmost importance for personnel evacuation. The paper investigates the smoke descent along a tunnel during a naturally ventilated tunnel fire. A theoretical model is developed to predict the smoke depth below the ceiling along the tunnel. A series of numerical simulations of full-scale tunnel fires are conducted to compare with the developed model, and some coefficients such as the entrainment coefficient are determined from the simulation results. The concepts of critical moment and critical distance are proposed to characterize the smoke descent along the tunnel. The results show that as the smoke spreads longitudinally, the smoke depth below the tunnel ceiling continuously increases. The temperature decay along the tunnel due to heat losses and air entrainment at the smoke layer interface is considered as the main parameter for the smoke descent. After the vitiated air returns back to the fire source, the smoke stratification in the entire tunnel will be significantly reduced. The smoke layer depth along the tunnel based on the temperature distribution is relatively stable in the process of smoke development, which is not sensitive to the HRR, but influenced by the tunnel width, and this method could only be used before the critical moment. The outcomes of this study could provide references for a better understanding of smoke movement in naturally ventilated tunnels and provide technical guidelines for fire safety designers.

  • 699.
    Zhou, R.
    et al.
    Institute of High Performance Computing Agency for Science & Technology and Research, Singapore.
    Xu, H.
    Institute of High Performance Computing Agency for Science & Technology and Research, Singapore.
    Fu, X.
    Institute of High Performance Computing Agency for Science & Technology and Research, Singapore.
    Yin, X. F.
    Institute of High Performance Computing Agency for Science & Technology and Research, Singapore.
    Qin, Z.
    Institute of High Performance Computing Agency for Science & Technology and Research, Singapore.
    Zhao, L.
    Institute of High Performance Computing Agency for Science & Technology and Research, Singapore.
    Verma, P.
    PSA International, Singapore.
    Lind, Mikael
    RISE Research Institutes of Sweden, Säkerhet och transport, Maritima avdelningen.
    Maritime Disruption Impact Evaluation Using Simulation and Big Data Analytics2022Inngår i: Proceedings - Winter Simulation Conference, Institute of Electrical and Electronics Engineers Inc. , 2022, s. 784-795Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Disruptions in maritime networks may cause significant financial burden and damage to business. Recently, some international ports have been experiencing unprecedented congestions due to the COVID19 pandemic and other disruptions. It is paramount for the maritime industry to further enhance the capability to assess and predict impacts of disruptions. With more data available from industrial digitization and more advanced technologies developed for big data analytics and simulation, it is possible to build up such capability. In this study, we developed a discrete event simulation model backed with big data analytics for realistic and valid inputs to assess impacts of the Suez Canal blockage to the Port of Singapore. The simulation results reveal an interesting finding that, the blockage occurred in the Suez Canal can hardly cause significant congestion in the Port of Singapore. The work can be extended to evaluate impacts of other types of disruptions, even occurring concurrently. 

  • 700.
    Zirgulis, Giedrius
    et al.
    RISE Research Institutes of Sweden, Samhällsbyggnad, Infrastruktur och betongbyggande.
    Nejad Ghafar, Ali
    Implenia Sverige AB, Sweden.
    Arun Chaudhari, Ojas
    RISE Research Institutes of Sweden, Samhällsbyggnad, Infrastruktur och betongbyggande.
    Development of dynamic grouting under laboratory and field conditions2022Inngår i: Geomechanics and Tunneling, ISSN 1865-7362, E-ISSN 1865-7389, Vol. 15, nr 5, s. 535-539Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    When it comes to underground structures, water ingress from the surrounding formations leads to several environmental, economic and sustainability issues. To obtain the sealing, the grouting of rock fractures is done. Today, in the grouting operations, which are commonly conducted in almost all the tunnel and subsurface infrastructure projects, the pressure applied is static. This type of applied pressure might be suitable for the large fracture apertures > 100 μm, but it has been acknowledged that it is difficult to obtain sufficient penetration through smaller apertures, where filtration of cement particles starts to occur. Research is already done to overcome this issue by applying dynamic grouting pressure instead of static. It was proved that this approach erodes the formed filter cakes and improves grout penetrability in fractures below 100 μm. This research focuses on low-frequency rectangular pressure impulse as an alternative to other methods. The goal is to improve grout spread in micro-fractures (especially in apertures < 70 μm). During the investigation, a prototype dynamic injection equipment was built and tested under laboratory conditions. The 4 m variable aperture long slot (VALS) was used in the experiments to simulate rock fractures. The test showed better grout penetrability using dynamic pressure approach. At the current time of writing this article, preparation works are done for field test of prototype equipment at SKB Hard Rock Laboratory (HRL) at Äspö, Sweden. 

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