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  • 1.
    Andersson, H.
    et al.
    Univ Gavle, Sweden.
    Cehlin, M.
    Univ Gavle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Univ Gavle, Sweden.
    Experimental and numerical investigations of a new ventilation supply device based on confluent jets2018In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 137, p. 18-33Article in journal (Refereed)
    Abstract [en]

    In developed countries, heating, ventilation, air conditioning (HVAC) systems account for more than 10% of national energy use. The primary function of a HVAC system is to create proper indoor environment. A number of ventilation strategies have been developed to minimize HVAC systems energy use whilst still maintaining a good indoor environment. Among these strategies are confluent jet ventilation and variable air volume. In this study, an air supply device with a novel nozzle design that uses both of the above-mentioned strategies was investigated both experimentally and numerically at three different airflow rates. The results from the numerical investigation using the SST k - omega turbulence model regarding velocities and flow patterns are validated by experimental data carried out by Laser Doppler Anemometry. The results from both studies show that the flow pattern and velocity in each nozzle is directly dependent on the total airflow rate. However, the flow pattern does not vary between the three different airflow rates. The numerical investigation shows that velocity profiles for each nozzle have the same pattern regardless of the airflow rate, but the magnitude of the velocity profile increases as the airflow increases. Thus, a supply device of this kind could be used for variable air volume and produce confluent jets for the airflow rates investigated.

  • 2.
    Andersson, Harald
    et al.
    Univ Gavle, Sweden.
    Cehlin, Mathias
    Univ Gavle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Univ Gavle, Sweden.
    A Numerical and Experimental Investigation of a Confluent Jets Ventilation Supply Device in a Conference Room2022In: Energies, E-ISSN 1996-1073, Vol. 15, no 5, article id 1630Article in journal (Refereed)
    Abstract [en]

    In this study, confluent jets ventilation (CJV) supply devices with three different nozzle arrays (1 x 19, 2 x 19, 3 x 19) were investigated both numerically and experimentally at two different airflow and supply air temperature set-ups. The performance of the CJV supply devices was investigated concerning thermal comfort, indoor air quality (IAQ), and heat removal effectiveness in a conference room environment. A comparison between the experimental and numerical results showed that the & thetasym;(2) over bar -f model had the best agreement out of the investigated turbulence models. The numerical results showed that the size of the array had a great impact both on near-field development and on the conditions in the occupied zone. A larger array with multiple rows and a lower momentum conserved the inlet temperature and the mean age of the air better than a single-row array with a higher momentum. A larger array with multiple rows had a higher IAQ and a greater heat removal effectiveness in the occupied zone because the larger array conserved the mean age of air better and the buoyancy driven flow was slightly better at removing the heat. Because of the lower inlet velocities, they also had lower velocities at ankle level, which decreased the risk of draft and thermal discomfort.

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  • 3.
    Andersson, Harald
    et al.
    Univ Gavle, Sweden.
    Kabanshi, Alan
    Univ Gavle, Sweden.
    Cehlin, Mathias
    Univ Gavle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Univ Gavle, Sweden.
    On the Ventilation Performance of Low Momentum Confluent Jets Supply Device in a Classroom2020In: Energies, E-ISSN 1996-1073, Vol. 13, no 20, article id 5415Article in journal (Refereed)
    Abstract [en]

    The performance of three different confluent jets ventilation (CJV) supply devices was evaluated in a classroom environment concerning thermal comfort, indoor air quality (IAQ) and energy efficiency. The CJV supply devices have the acronyms: high-momentum confluent jets (HMCJ), low-momentum confluent jets (LMCJ) and low-momentum confluent jets modified by varying airflow direction (LMCJ-M). A mixing ventilation (MV) slot jet (SJ) supply device was used as a benchmark. Comparisons were made with identical set-up conditions in five cases with different supply temperatures (T-S) (16-18 degrees C), airflow rates (2.2-6.3 ACH) and heat loads (17-47 W/m(2)). Performances were evaluated based on DR (draft rating), PMV (predicted mean vote), ACE (air change effectiveness) and heat removal effectiveness (HRE). The results show that CJV had higher HRE and IAQ than MV and LMCJ/LMCJ-M had higher ACE than HMCJ. The main effects of lower T-s were higher velocities, DR (HMCJ particularly) and HRE in the occupied zone as well as lower temperatures and PMV-values. HMCJ and LMCJ produce MV conditions at lower airflow rates (<4.2 ACH) and non-uniform conditions at higher airflow rates. LMCJ-M had 7% higher HRE than the other CJV supply devices and produced non-uniform conditions at lower airflow rates (<3.3 ACH). The non-uniform conditions resulted in LMCJ-M having the highest energy efficiency of all devices.

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  • 4.
    Andersson, Sonja
    Linköping University, Department of Science and Technology.
    Bostadsanpassningsbidrag i Norrköpings kommun2003Independent thesis Basic level (professional degree)Student thesis
    Abstract [sv]

    Funktionshindrade personer har möjlighet att få sin bostad anpassad så ett de kan leva ett självständigt liv i ett eget boende. Anpassningen betalas av kommunen genom ett bostadsanpassningsbidrag. De senaste åren har, inom Norrköpings kommun, kostnaderna för bostadsanpassningsbidrag ökat kraftigt och överstigit den budget som tilldelats. Syftet med den här rapporten är att undersöka hur andra kommuner arbetar med handläggning och upphandling av bostadsanpassningsärenden. En del frågor rör även åldersfördelningen.

    För att få en uppfattning om hur arbetet med bostadsanpassningsbidrag bedrivs ute i kommunerna har jag valt att göra en enkätundersökning. Kommunerna i undersökningen är valda efter invånarantal, jämförbara med Norrköping. Jämförelsen med andra kommuner visar att i stort sett alla jobbar på samma sätt när det gäller upphandlingar och ersättningsformer. Det går inte att säga att en ersättningsform är mer kostnadseffektiv än en annan när det gäller bostadsanpassningar. Kostnaden per ärende varierar stort hos de olika kommunerna. Jag kan konstatera att Norrköping ligger bland de som har den högsta kostnaden.

    Löpande räkning är den absolut vanligaste ersättningsformen. I ända upp till 90 % av alla ärenden i vissa kommuner används denna ersättningsform. Annars svarar de flesta att de också tillämpar löpande räkning med takpris och fast pris på anbud. Åldersfördelningen ser likadan ut i kommunerna i undersökningen. Genomsnittet av andelen personer över 75 år är 58 % och den överensstämmer med den siffra jag kom fram till i åldersfördelningen för bostadsanpassningsbidrag i Norrköpings kommun. Däremot ligger kostnaden för dessa ärenden något högre i Norrköping. Gemensamt för samtliga tillfrågade är att de anser att det byggs alltför lite anpassade bostäder för äldre. Detta återspeglar sig i ökade kostnader för bostadsanpassningsbidrag. I stora drag arbetar de tillfrågade kommunerna på samma sätt med handläggning av ärenden.

    För att komma tillrätta med de höga kostnaderna för bostadsanpassningsbidrag i Norrköpings kommun krävs att en mer omfattande undersökning görs. Enskilda ärenden skulle behöva jämföras för att se hur andra kommuner har beslutat, handlagt och upphandlat liknande fall.

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  • 5.
    Apostolopoulou-Kalkavoura, Varvara
    et al.
    Stockholm Univ, Sweden.
    Hu, Shiqian
    Univ Tokyo, Japan.
    Lavoine, Nathalie
    NC State Univ, NC 27695 USA.
    Garg, Mohit
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Linares, Mathieu
    Linköping University, Department of Physics, Chemistry and Biology, Bioinformatics. Linköping University, Faculty of Science & Engineering.
    Munier, Pierre
    Stockholm Univ, Sweden.
    Zozoulenko, Igor
    Linköping University, Department of Science and Technology, Laboratory of Organic Electronics. Linköping University, Faculty of Science & Engineering.
    Shiomi, Junichiro
    Univ Tokyo, Japan.
    Bergstrom, Lennart
    Stockholm Univ, Sweden.
    Humidity-Dependent Thermal Boundary Conductance Controls Heat Transport of Super-Insulating Nanofibrillar Foams2021In: Matter, ISSN 2590-2393, E-ISSN 2590-2385, Vol. 4, no 1Article in journal (Refereed)
    Abstract [en]

    Cellulose nanomaterial (CNM)-based foams and aerogels with thermal conductivities substantially below the value for air attract significant interest as super-insulating materials in energy-efficient green buildings. However, the moisture dependence of the thermal conductivity of hygroscopic CNM-based materials is poorly understood, and the importance of phonon scattering in nanofibrillar foams remains unexplored. Here, we show that the thermal conductivity perpendicular to the aligned nanofibrils in super-insulating icetemplated nanocellulose foams is lower for thinner fibrils and depends strongly on relative humidity (RH), with the lowest thermal conductivity (14 mW m(-1) K-1) attained at 35% RH. Molecular simulations show that the thermal boundary conductance is reduced by the moisture-uptake-controlled increase of the fibril-fibril separation distance and increased by the replacement of air with water in the foam walls. Controlling the heat transport of hygroscopic super-insulating nanofibrillar foams by moisture uptake and release is of potential interest in packaging and building applications.

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  • 6.
    Arghand, Taha
    et al.
    Högskolan i Gävle, Energisystem.
    Karimipanah, Taghi
    Högskolan i Gävle, Energisystem.
    Awbi, Hazim
    School of Construction Management and Engineering, University of Reading, United Kingdom.
    Cehlin, Mathias
    Högskolan i Gävle, Energisystem.
    Larsson, Ulf
    Högskolan i Gävle, Energisystem.
    Linden, Elisabet
    Högskolan i Gävle, BMG-labbet.
    An experimental investigation of the flow and comfort parameters for under-floor, confluent jets and mixing ventilation systems in an open-plan office2015In: Building and Environment, ISSN 0360-1323, E-ISSN 1873-684X, Vol. 92, p. 48-60Article in journal (Refereed)
    Abstract [en]

    There is a new trend to convert the workplaces from individual office rooms to open offices for motivating money saving and better communication. With such a shift the ability of existing ventilation systems in meeting the new requirements is a challenging question for researchers. The available options could have an impact on workers' health in terms of providing acceptable levels of thermalcomfort and indoor air quality. Thus, this experimental investigation focuses on the performances of three different air distribution systems in an open-plan office space. The investigated systems were: mixing ventilation with ceiling-mounted inlets, confluent jets ventilation and underfloor air distribution with straight and curved vanes. Although this represents a small part of our more extensiveexperimental investigation, the results show that all the purposed stratified ventilation systems (CJV and UFAD) were more or less behaving as mixing systems with some tendency for displacement effects. Nevertheless, it is known that the mixing systems have a stable flow pattern but has the disadvantage of mixing contaminated air with the fresh supplied air which may produce lower performance and in worst cases occupants' illness. For the open-plan office we studied here, it will be shown that the new systems are capable of performing better than the conventional mixing systems. As expected, the higher air exchange efficiency in combination with lower local mean age of air for corner-mounted CJV and floor-mounted UFAD grills systems indicates that these systems are suitable for open-plan offices and are to be favored over conventional mixing systems.

  • 7.
    Aronsson, Mattias
    et al.
    Linköping University, Department of Science and Technology.
    Karlsson, Jimmy
    Linköping University, Department of Science and Technology.
    Jämförelse av produktionsmetoder vid byggande av gång- och cykeltunnel.2003Independent thesis Basic level (professional degree)Student thesis
    Abstract [sv]

    Vi har i denna rapport jämfört produktionsmetoder vid byggande av gång- och cykeltunnel under järnväg. de metoder vi har jämfört är lansering och platsgjutning. Projektet som vi har studerat är byggandet av en gong- och cykeltunnel under järnväg vid Mjölby station. Vid detta projekt lanseras halva tunneln in och halva platsgjuts.

    Det vi har jämfört är dels de geotekniska aspekterna, där vi främst har tittat på vikten av förundersökningar, jordegenskapens inverkan, spontning och grundvattnets inverkan. Vi har också tittat på produktionstekniska aspekter, då främst storleken av arbetsområdet och arbetsmiljön. Vi har även betraktat ekonomi och produktionstid i de båda metoderna.

    Vi har i denna rapport främst använt oss av muntliga källor som gett sina synpunkter på hur tunneln ska eller bör utformas. Vi har sedan sammanställt alla synpunkter och åsikter och skaffat oss en egen uppfattning om de båda metoderna och när de bör användas.

    Det vi kommit fram till när vi har jämfört dessa båda metoder är att lansering har många fördelar vad gäller arbetsmiljö, tid och ekonomi. vid enklare tunnelprojekt är denna metod att föredra om förutsättningar finns. platsgjutning har dock de fördelar att den kan användas vid de flesta tunnelbyggnationer och att tågtrafiken kan flyta på utan längre störningar.

    Vid stora projekt som det i Mjölby anser vi att en kombination av metoderna är den allra bästa lösningen.

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  • 8.
    Aslan, Jiyan
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Asp, Marcus
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Jointed timber column with glue or nails.2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    På en byggarbetsplats kan man ibland behöva sammansätta två eller flera träkomponenter till en träkomponent med rätt dimension. Det sker oftast genom spikning men det finns också möjlighet att limma ihop träkomponenter ute på en byggarbetsplats. Limning är inte alls lika förekommande på grund av de krav som ställs på limning av bärande konstruktioner och kringliggande miljö varför limning i princip endast sker i fabriksmiljö. I denna studie utförs en jämförelse mellan sammansättning av träreglar till en träpelare med avseende på hållfasthet och ekonomi. Detta jämförs dessutom med att köpa in pelare av trä med rätt dimension. I studien behandlas dessutom möjligheten att limma ute på en byggarbetsplats och hur limningen ska utföras på ett korrekt sätt. Studien har genomförts med hjälp av de standarder som finns för beräkningsregler för dimensionering av bärverk, eurokoder. Kostnadsberäkningar har genomförts för material och utförandearbete med hjälp av marknadspriser för material och enkla beräkningar för utförandearbete. En intervju har genomförts för att besvara möjligheten att limma ute på en byggarbetsplats med lim för bärande konstruktioner. I studien har beräkningar utförts för två samt tre sammansatta träreglar och jämförts med enkla pelare i liknande dimensioner. Spikad pelare har en avsevärt lägre bärförmåga än limmad pelare som är utförd korrekt. Spikad pelare har beräknats med olika avstånd mellan spikar och limmad pelare är beräknad med två olika lim. Kostnaderna för material och utförandearbete är ganska generella men är bara en liten del av de totala kostnaderna. Vart byggarbetsplatsen är placerad, vilka verktyg och material som finns på plats och vilka förutsättningar för att utföra limningen korrekt är faktorer som är avgörande för den totala kostnaden. Ett limförband är känslig och viktigast är att applicera rätt mängd och jämnt utbrett över träytorna. Vad som dessutom ska tas till hänsyn är kringliggande miljö såsom smuts, damm, temperatur och fuktighet. För att uppfylla dessa krav ute på en byggarbetsplats måste en fabriksmiljö skapas i form av väderskydd, tält, arbetsbod eller liknande.

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  • 9.
    Atto, Andreas
    Linköping University, Department of Science and Technology.
    Byggprocessen i förändring - Visionen om BIM2011Independent thesis Basic level (professional degree), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The primary purpose of this thesis can be said to be to create a perception at Skanska Civil Southeast, which is the initiator of this thesis, on what BIM (Building Information Model) is and how it can most easily be implemented in their work processes. It would be impossible to cover all aspects of BIM in the short amount of time that has been available and in the context of this thesis, therefore, the aspects that were deemed important to the company and to the author has been picked up for investigation.

    To achieve this, the task of the thesis is to identify and highlight the differences between today's construction process, and BIM (Building Information Model) and from that suggest possible ways to implement this way of working to Skanska Civil Southeast.

    The thesis first chapter provides a brief introduction and background to the construction process and how it has changed over time. A purpose and questions on which the thesis is being based on are formulated and a boundary for the thesis is done.

    The thesis second chapter provides the theoretical background to today's construction process. Key aspects of today's construction process are highlighted and explained. This is followed by a presentation of the concept of BIM and what it means. After that, a brief review of how the work with BIM looks at Skanska Sweden AB and in the construction industry generally.

    The thesis third chapter presents how BIM is currently used on a road project just outside of Katrineholm in a project called Förbifart Katrineholm where BIM is being applied to some extent. The differences that exist between today’s construction process and the BIM and the pros and con that can be observed in BIM relative to today's construction process is presented.

    In the thesis fourth chapter answers the questions and the results are analyzed and discussed on important aspects of construction, to, in the fifth chapter make concrete proposals on how an implementation of BIM in Skanska Civil Southeast work processes may look like.

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  • 10.
    Bengtsson, Agnes
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Hagberg Fyrberg, Julia
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Miljöanpassade och kostnadseffektiva flerbostadshus2019Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Syftet med detta examensarbete är att undersöka om man kan bygga miljömässigt hållbart utan att det behöver kosta mer. På grund av kostnadsökningar för byggandet av miljövänliga hus byggs inte dessa i samma utsträckning som önskat, vilket är nödvändigt då byggsektorn bidrar till stora utsläpp av miljöfarliga ämnen. Vi har undersökt om man kan effektivisera användningen av miljömässigt hållbara material utifrån Sweden Green Building Council’s miljöklassificering från ett kostnadsperspektiv. Av de 15 punkter som presenteras som bedömningskriterier för certifiering Miljöbyggnad av nyproduktioner tittar vi närmare på 3 av punkterna: Energianvändning, ljud och ventilation.

    Studien har genomförts på uppdrag av Riksbyggen och rapporten riktar sig främst till beställare och entreprenörer men resultatet är något som rör alla som befinner sig i byggbranschen.

    Informationen som legat till grund för denna rapport är insamlat från tidigare forskning via LiU’slitteratursökningssida samt intervjuer med projektörer, leverantörer och installationssakkunnigför närmare information angående uppdaterade priser och installationsalternativ.

    I slutsatsen av rapporten kan man se vilka olika byggdelar som har använts vid energiåtgång, ljud och ventilation och vad de olika byggdelarna har kostat, resultatet presenteras som en procentsats i ökning som utgår från BBR’s byggkrav. Även en procentsatssökning har tagits fram på de olika byggdelarna som uppnår nivå silver där mer kostnadseffektiva alternativ presenteras.

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    Miljöanpassade och kostnadseffektiva flerbostadshus
  • 11.
    Bertilson, Anton
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    The quality of quality controls. A study of the controlls for certifying building according to Miljöbyggnad.2014Independent thesis Basic level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Miljöbyggnadscertifieringarna har ökat markant sen systemet lanserades och allt fler byggnader uppförs i Sverige idag med stort miljöfokus. Men hur bra är kvalitetskontrollerna som ska säkerställa att byggnaden uppfyller certifieringskraven? Denna rapport syftar att svara på hur noggrant kvalitetskontrollerna för certifiering av Miljöbyggnad utförs samt hur bra dessa kontroller är på att säkerställa certifieringen ur ett kvalitetsperspektiv. För att svara på syftet så undersöks och kartläggs det vilka kvalitetskontroller som gjorts på referensobjektet framtidens US i Linköping. Efter att kvalitetskontrollerna kartlagts så har de utvärderas och fått ett betyg efter utvärderingsparametrar som tagits fram i samarbete med energiexpert, kvalitetssamordnare och miljösamordnare. Alla olika typer av kontrollers betyg har lett till ett samlat indikatorbetyg som återspeglar hur bra kontrollerna kring varje indikatorn är på att säkerställa kvalitén på certifieringen. Resultatet ger en spridd bild över hur bra kontrollerna är på att säkerställa kvalitén på certifieringen. Det förekommer höga felmarginaler i kontrollerna och detta leder till ett sämre betyg. Generellt så har indikatorbetygen varit väldigt bra när det gäller att säkerställa kvalitén på certifieringen.

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  • 12.
    Björklöf, Sune
    Linköping University, Department of Management and Economics. Linköping University, Faculty of Arts and Sciences.
    Byggbranschens innovationsbenägenhet: En studie om den svenska byggbranschens inställning till innovationer och branschens beredskapatt hantera innovationsfrågor1986Doctoral thesis, monograph (Other academic)
    Abstract [en]

    The attitude of the building sector towards innovation and its intellectual and organizational preparedness for dealing with the issues of innovation is the aim of this study. The core question can be formulated as follows: Why does a building company accept certain innovations but not others? The fundamental ideas of the study are rooted in the central European tradition of the historico-qualitiative school of thought. Another basic idea for the thesis is Dewcy’s and Bcntley's theory of transactional cognition introduced in Sweden by Hanssen under the term ""field concept" according to which the content and object of knowledge are seen as an entirety. The reason for approaching the problem qualitatively. that is through not highly structured interviews based on the author's long personal experience in the sector, is its compound and many face ted nature a long with the fact that verbal discussion is firmly grounded in building sector tradition.

    Innovations has to pass trough three different filters. These filters are at the point where the innovation enters the company, during the bid preparation process and upon the absorption of the innovation into the project. Important factors influencing the passage through these filters arc papyrophobia, the old boy network (OBN) and the structure of the production system. Papyrophobia is expressed in a general reluctance to deal with theoretical issues and documentation. OBN denotes an informal communication network. Production is run by and within project organizations. i.e. repetitive ad hoc aggregates independent of the parent organization. These factors in combination with time and financial pressure obstruct the possibility of creating a research tradition.

    Characteristic features of the socio-cultural tradition of the sector are that it is male dominated, that the educational system classifies those working in the field according to trade and profession, and that the strong position of production aspects have brought to the forefront the energetic practitioner. His values are strictly professional. Information is to a great extent transmitted orally. There is strength in the ability of Swedish construction firms to plan and improvise within an established frame. However, a certain streak of marginalism with the potential of inhibiting innovation does exist in their pattern of action. Also typical of the tradition is the ideal of the free entrepreneur and the organization of large companies as confederations of a number of small and medium size firms. Finally, a fundamental cultural feature of the construction industry is openness. News spreads rapidly to a competitor.

    Innovations are disseminated in several ways, but one dominant pattern persists that cannot be seen in other industries. While the projects are important for testing and diffusion of innovations, the companies arc more intrumental in propagating information of innovations. The building materials industry's R&D work follows a pattern similar to that of production companies in other sectors.

    The building sector's readiness to follow and work with innovation issues can generally be rated as low. The confinement of interest to production aspects combined with the marked open· ness provides ample room for the materials manufacturers and companies outside the sector to introduce new products and materials. In the long run, it is the gradual change in this assortment that will transform building techniques and technology. Change is generated by other sectors.

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  • 13.
    Bodin, Gustav
    et al.
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    Jaber, Momamed
    Linköping University, Department of Science and Technology, Media and Information Technology. Linköping University, The Institute of Technology.
    Energiberäkning för påbyggnader2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Saving energy is important both economically and environmentally.

    The way we in Sweden build our houses and the rules that govern our energy usage has varied over the years.

    Åtvidabergstakvåningar is a company that perform superstructures in the shape of new penthouses for villas. Åtvidabergstakvåningar came with the initiative for the study, too get a picture of how the energy usage transformed for villas equipped with their penthouses. They also came with the initiative for the method to create time distinct villas and equip these with their penthouses.

    The study gives a picture of how the building envelop is composed and how the energy loss is through it. The study will also compare how the rules that govern energy loss and usage have transformed over the years.

    The result of the Study is an energy calculation that declares the energy usage for the time distinct villas with and without penthouses.

    The Result of the study shows that the older houses get a better energy performance after adding on the penthouses, while the new house got a value that was similar.

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  • 14.
    Boiadjiev, Borislav
    Linköping University, Department of Science and Technology.
    Undersökning av skalväggs egenskaper utan igjutning med betong2006Student paper second term, 10 points / 15 hpStudent thesis
    Abstract [en]

    Double walls normally consist of two concrete shells 45-75 mm thick with an air column them between. The shells in the wall are held together with reinforcement’s bars. The air column even breadth depends on the wall's total thickness and is (cast in place) founded in on-the-spot. The objective with this work is to examine double walls direct properties then the air column is without concreting. If the double walls are found to have good resistance it can begin to be used instead of massive walls.

    The calculations for the resistance are carried out partially with FEM programme (Finite Element method programme) and partially with complementary hand calculations. The calculations for fire dimension ring and acoustic properties are implemented according to simplified calculation methods.

    The results show that double walls directly can to take up a load corresponding to the weight of ten floors. In the reality double walls will not be used as carrying walls and the study is only a survey about how heavy loads the wall principally can carry.

    Weak points in the compound system are the reinforcement bars in the estimated load bearing structure. Their resistance creates the base for dimensioning and the design resistance increases with bigger bar diameter.

    The double walls meet the requirements for fire on minimal thickness and minimal concrete cover layer. According to the calculations the double walls has fire resistance corresponding to 1,5 MN pressures.

    The wall has, in the basis execution, a reduction number on R=45 dB according to the calculations. This can be enough to use them in building parts with lower requirements for air sound isolation.

    The double walls are a” half precast component” that is on the way to become a ”completely precast component”.

    The double walls have according to the calculations good possibilities to replace massive walls and with possible completions for fire - and sound isolation can the usage be increased.

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  • 15.
    Bondarevs, Andrejs
    et al.
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Huss, Patrik
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Gong, Shaofang
    Linköping University, Department of Science and Technology, Physics and Electronics. Linköping University, Faculty of Science & Engineering.
    Weister, Ola
    Vertical Plants System Sweden AB.
    Liljedahl, Roger
    Vertical Plants System Sweden AB.
    Green walls utilizing Internet of Thing2015In: Sensors & Transducers Journal, ISSN 2306-8515, E-ISSN 1726-5479, Vol. 192, no 9, p. 16-21Article in journal (Refereed)
    Abstract [en]

    A wireless sensor network was used to automatically control the life-support equipment of a green wall and to measure its influence on the air quality. Temperature, relative humidity, particulate matter, volatile organic compound and carbon dioxide were monitored during different tests. Green wall performance on improving the air quality and the influence of the air flow through the green wall on its performance were studied. The experimental results show that the green wall is effective to absorb particulate matter and volatile organic compound. The air flow through the green wall significantly increases the performance. The built-in fan increases the absorption rate of particulate matter by 8 times and that of formaldehyde by 3 times.

  • 16.
    Bonnevier, Björn
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Karlsson, Robin
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Effektivisering av vindlastberäkningar2019Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Det här examensarbetet har utförts på uppdrag av WSP Sverige i Norrköping och i samarbete med deras kund OBOS. Enligt Jörgen Vahlström (2019) har OBOS ett behov av att effektivisera arbetet med vindlastberäkningar. Metoden som OBOS använder idag är tidskrävande och ger en viss överdimensionering.

    För att effektivisera beräkningarna har en beräkningsmall baserat på Eurokod utvecklats i Excel. Alla nödvändiga parametrar enligt Eurokod matas in för att utföra beräkningarna och ett resultat sammanställt på ett strukturerat sätt presenteras. För att mäta effektiviseringen jämförs tider för beräkning samt total horisontell vindlast.

    Slutsatsen från studien är att det går att effektivisera beräkningsgången och samtidigt höja kvalitén genom att använda en beräkningsmall. Det går i snitt att spara 78% i beräkningstid och reducera kraften med 15% genom att beräkna med en mer exakt metod.

    I rapporten diskuteras även hur väl de förenklingar som finns i Eurokod som behandlar invändig vindlast täcker in de mer exakta beräkningsmetoderna.

    Vår slutsats är att Eurokods förenklingar för beräkning av invändig vindlast är väl fungerande för till exempel småhus där det inte finns några extrema öppningar och där öppningarna är jämnt fördelade över byggnadens alla sidor.

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    Effektivisering av vindlastberäkningar
  • 17.
    Borg, Andreas
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Karlsson, Christopher
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    A study of air leakage around window constructions2015Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Det finns flera kritiska punkter i en byggnad där luft kan ta sig in, exempelvis genomföringar i klimatskalet för elrör och vattenrör, anslutningar i klimatskalet i form av dörrar och fönster samt skarvar i byggandens tätskikt. Tätningen kring just fönster är en av de detaljer som det tilldelas mest resurser till. Två grundläggande moment är avgörande för hur stort luftläckage det kan bli; hur tätskiktet avslutas kring fönsteröppningen och vilken tätningsprincip som används. Med detta som en grund har syftet med den här studien varit att ta fram vilka fler parametrar kring en fönsterkonstruktion som är avgörande för dess lufttäthet samt vilka olika typer av tätningsmetoder det finns. Rapporten har tagits fram genom en litteratur- och fältstudie tillsammans med möten med personer i branschen.

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  • 18.
    Brege, Staffan
    et al.
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    Nord, Tomas
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    Brege, Harald
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    Holtström, Johan
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    Sjöström, Roland
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    The Swedish wood manufacturing sector: findings from a contextually adapted structure-conduct-performance model2021In: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 17, no 6, p. 878-886Article in journal (Refereed)
    Abstract [en]

    The scope of this article is an inter-industry study of the Swedish Wood Manufacturing Sector (WMS), examined from the perspective of the Structure-Conduct-Performance (SCP) paradigm in the theoretical field of Industrial Organization. The four research questions are: (1) identify the industries within the sector, (2) construct a contextually adapted SCP model and form the basis for hypotheses of relationships between the different variables in the model, (3) establish quantitative correlations between the variables, and finally (4) present a basically qualitative, explanatory interpretive analysis. The empirical investigation is a total population study of 311 firms. Nine industries are identified, and an SCP model is presented including four explanatory variables - exposure to international competition, value-added scope, domestic demand growth potential and (domestic industry) seller concentration - and two performance variables - industry profitability (ROA) and industry growth. The combined qualitative and quantitative explanatory analysis identifies some important relationships in the SCP model. The most prominent findings are the strong negative relationships between exposure to international competition and industry profitability and industry growth. Another finding is that strong positive relationships are found between the degree of value-added scope and industry profitability and industry growth.

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  • 19.
    Dahlqvist, Erik
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Farman, Daniel
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Är Rockpanel framtidens fasadskiva?2020Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Olika fasadskivor har under många år klätt svenska byggnader. Eternit och fibercement är exempel på produkter som länge varit populära. 2018 lanserades en ny fasadskiva i Sverige, rockpanel. Rockpanel används av PEAB i Vikingstad på 27 nyproducerade radhus där man under projekteringen till en början tänkt använda fibercement. Studien har undersökt hur PEAB påverkas av materialbytet från fibercement till rockpanel i tid och resurser. Utöver detta har rockpanelen även jämförts med liknande fasadmaterial utifrån hållbarhet, arbetsmiljö och tekniska egenskaper. Detta har gjort för att utvärdera rockpanelen som fortfarande är relativt okänd för aktörerna i byggbranschen och för att komplettera tidigare studier där rockpanelen inte undersökts djupgående. Studien visar att rockpanelen är tidseffektiv, hållbar, lätthanterad och kan användas för många olika fasadlösningar.

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  • 20.
    Dahlqvist, Thomas
    et al.
    Linköping University, Department of Science and Technology.
    Parbrand, Mårten
    Linköping University, Department of Science and Technology.
    Dataprogram för beräkning av pålfundament och felslagning av pålar2002Independent thesis Basic level (professional degree)Student thesis
    Abstract [sv]

    Syftet med detta examensarbete är att producera ett dataprogram som dimensionerar pålfundament samt beräknar felslagning av pålar. Ett pålfundaments funktion är att via pålar överföra laster till berg eller fasta jordlager. Felslagning inträffar då pålar inte hamnat på rätt koordinater eller glidit snett ned i marken och ej kan användas. Med hjälp av felslagningsprogrammet erhålles nya påkoordinater för nästkommande påle, vilken måste placeras ut så att tyngdpunkten för hela pålsystemet skall hamna rätt. Programmeringsspråket vi använt oss av är Visual Basic, där vi har omvandlat teoretiska beräkningar till databeräkningar. Detta har resulterat i ett dataprogram som beräknar 2-, 3- och 4-pålsfundament samt tar fram en ny påles koordinater vid felslagning. Vid beräkning av pålfundament tas hänsyn till armeringsmängd, förankring, sprickbildning samt spjälkning.

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  • 21.
    Davidsson, Sara
    et al.
    Linköping University, Department of Science and Technology.
    Bagger, Conny
    Linköping University, Department of Science and Technology.
    Lufttäta byggnader2010Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The viscosity of air buildings is a hot topic within the construction performers, which the industry feel they have too little knowledge about. This study is mainly aimed against air density in apartment buildings and airflow measurement. The study consists of a theoretical reference, educational visit, interviews and a survey conducted among construction workers at Magistratshagen in Linkoping.

    Earlier requirement in terms of air leakage through the climate screen was removed and today there are only energy requirement for a dwelling in Boverkets Building Regulations. The difference between a passive and a typical air tight construction is that the passive house have a maximum requirement of 0.3 l /s m2 of air leakage through the building climate screen. The requirement imposed on passive houses is to minimize the supply of power and energy for heating the building.

    Air tight constructions have heavy demands on the performance and accuracy of everyone involved with the project. The client must specify their requirements and also be prepared to pay for any additional costs. The architect and building planners have to design the building with regard to air tightness. Finally, the construction workers are required to do a careful work in order to get all the connections in the building air tight.

    The study suggests that an air tight building is a closed system where no forced ventilation exists. There are no reasons not to build too tight as long as there is a functioning ventilation. In this study the authors ask themselves how an air tight building changes over time. No theoretical information has been found on these changes, but the respondents assume that air density decreases with time. The deterioration is mainly assumed to be caused by construction materials changes over time. The study shows that construction workers knowledge of air tight construction is mixed, which they themselves admit in the survey.

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  • 22.
    Dermentzis, Georgios
    et al.
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria.
    Ochs, Fabian
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria.
    Gustafsson, Marcus
    Linköping University, Department of Management and Engineering, Environmental Technology and Management. Linköping University, Faculty of Science & Engineering.
    Calabrese, Toni
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria.
    Siegele, Dietmar
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria.
    Feist, Wolfgang
    Unit for Energy Efficient Building, University of Innsbruck, Innsbruck, Austria; Passive House Institute, Darmstadt, Germany.
    Dipasquale, Chiara
    EURAC Research, Bolzano, Italy.
    Fedrizzi, Roberto
    EURAC Research, Bolzano, Italy.
    Bales, Chris
    Energy Technology, Dalarna University, Falun, Sweden.
    A comprehensive evaluation of a monthly-based energy auditing tool through dynamic simulations, and monitoring in a renovation case study2019In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 183, p. 713-726Article in journal (Refereed)
    Abstract [en]

    An energy auditing tool (PHPP) was evaluated against a dynamic simulation tool (TRNSYS) and used for the assessment of energy conservation measures in a demo case study. The comprehensive comparison of heating and cooling useful demands and loads included three building types (single-, multi-family house, and office), three building energy levels (before renovation and after renovation with a heating demand of 45 and 25 kWh/(m²·a)) and seven European climates.

    Dynamic simulation results proved PHPP (monthly energy balance) to be able to calculate heating demand and energy savings with good precision and cooling demand with acceptable precision compared to detailed numerical models (TRNSYS). The average deviation between the tools was 8% for heating and 15% for cooling (considering climates with a relevant cooling load only). The higher the thermal envelope quality was, i.e. in case of good energy standards and in cold climates, the better was the agreement. Furthermore, it was confirmed that PHPP slightly overestimates the heating and cooling loads by intention for system design.

    The renovation design of a real multi-family house was executed using PHPP as energy auditing tool. Several calculation stages were performed for (a) baseline, (b) design phase, and (c) verification with monitoring in order to calculate the corresponding heating demand. The PHPP model was calibrated twice, before and after the renovation. The necessity for tool calibration, especially for the baseline, was highlighted increasing the confidence with respect to a number of boundary conditions.

    In this study, PHPP was tested as an energy auditing tool aiming to be a versatile and less error-prone alternative to more complex simulation tools, which require much more expert knowledge and training.

  • 23.
    Destino, Maló
    Linköping University, Department of Science and Technology.
    Kartläggning av behovet av bärighetshöjande åtgärder på mindre vägar2002Independent thesis Basic level (professional degree)Student thesis
    Abstract [sv]

    Detta examensarbete är utfört på uppdrag av Vägverket Region Syd. Sveriges vägnät håller på att anpassas till den europeiska standarden, men det finns fortfarande en hel del begränsningar kvar på mindre vägar. Vi har inte tillräcklig kunskap om vilka problem dessa begränsningar medför för tunga transporter och Vägverket är angeläget om att klarlägga, vilken nytta det skulle vara att göra förstärkningsåtgärder.

    Jag har undersökt ett landsbygdsområde i södra Östergötland och de begränsningar som finns här på flera vägar är dålig bärighet i första hand för broarna och hög tjälfarlighet. Syftet med undersökningen är att göra en kartläggning av de tunga godstransporterna och de problem begränsningarna på vägarna medför för näringslivet. Jag har använt både teoretiska och empiriska studier. De teoretiska studierna kan delas in i:

    - Allmänna tekniska beskrivningar för vägkonstruktioner

    - Lagar och bestämmelser för tunga fordon

    - Information och rapporter från Vägverket

    - Tidigare utförda undersökningar

    De empiriska studierna har utgjorts av intervjuer med olika transportörer i området. Intervjuerna har utförts för att få en bild av hur transportörerna uppfattar vägnätets begränsningar och hur detta påverkar deras verksamhet både praktiskt och ekonomiskt. Jag har intervjuat både stora företag som Södra Skog, Arla och Odal och mindre åkeriägare med ett fåtal lastbilar.

    Mina slutsatser är följande:

    1. Det är fyra vägar i det undersökta området som bör prioriteras när det gäller förstärkningsåtgärder och tjälsäkring.

    2. Vägverket bör undersöka möjligheterna att säkerställa en lätt och smidig kontakt mellan transportörer och de som ansvarar för underhållet av vägarna.

    3. Det verkar vara bättre hålla kvar de mindre grusvägar som finns kvar och underhålla dem bättre med hyvling, grus och eventuellt dikning i stället för att lägga en tunn asfaltbeläggning, som är mycket känslig för tung trafik och tjällossning.

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  • 24.
    Egerud, Rebecca
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Södergren, Erik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Cost differences between Miljöbyggnad Guld and BBR2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Denna rapport är en jämförelse mellan BBR och Miljöbyggnad nivå Guld. Tre frågeställningar besvaras, Vad är skillanden mellan BBR och Miljöbyggnad nivå guld, vad är mervärdet och merkostnaden av Miljöbyggnad nivå Guld. Studien är utförd på en fallstudie av Studenthuset som byggs på Linköpings Universitet. Resultaten av studien visar att skillanderna mellan de två är stora, mervärdet för Miljöbyggnad nivå Guld är stort samt att merkostnaden är 2.5 - 3.0 % för Miljöbyggnad nivå GUld

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    Cost differences between Miljöbyggnad Guld and BBR
  • 25.
    Ekeskär, Andreas
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Rudberg, Martin
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Third-party logistics in construction: the case of a large hospital project2016In: Construction Management and Economics, ISSN 0144-6193, E-ISSN 1466-433X, Vol. 34, no 3, p. 174-191Article in journal (Refereed)
    Abstract [en]

    The construction supply chain is of temporary nature and complex, with many interactions between multiple actors in different construction projects. This challenging context typically leads to relatively higher costs and lower productivity, compared to other industries. Supply chain management (SCM) has been put forward as a mean to better handle this challenging context. As a part of SCM initiatives some construction industry stakeholders have turned to third-party logistics (TPL) providers, especially in large construction projects. The use of TPL providers is a new, and under-investigated, phenomenon in the construction industry. The main purpose of this study is thus to explore the use of a TPL provider in a large construction project and to analyse its resulting effects. Driving forces and possible concerns for implementing TPL are identified and the possibility for TPL to be a facilitator for implementing SCM in construction is investigated. The research is based on a literature review and an explorative case study of a large hospital project in Sweden, where the client and the main contractor have initiated the use of a TPL provider to coordinate sourcing and materials handling activities on site. The results show positive effects on establishing an effective interface between the construction site and the supply chain. The results also show that a TPL solution facilitates an increase in productive work at the construction site itself, a reduction of costs and an increased utilisation of site assets. On the downside, the study also shows a lack of SCM knowledge amongst the involved actors in the project, hindering them to reap the full potential of TPL.

  • 26.
    El Halabi, Philip
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Holm, Joel
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Experimentdesign för jämförelse av isoleringsmaterials teoretiska och verkliga isoleringsförmåga2019Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    In recent decades, the increasing requirements of energy use in buildings have resulted in a demand for more well-insulated and airtight structures.The theoretical insulation capacity of an insulating material is determined during tests performed in a laboratory environment. The problem is that these conditions differ significantly from real conditions.The purpose of this thesis is to investigate the U-value of insulating materials in real conditions. The thesis does not include execution ofexperiments. Furthermore, the study is limited to Swedish conditions and two insulation materials: polyurethane and mineral wool. For this purpose,two problem statements have been formulated:

    • What is the need for testing insulating material’s true insulating abilities?

    • Which method is more suitable for examining insulating material's true insulating ability, studying the heating needs of existing buildings or experiment modules? The study was based on literature studies where the following information and data were studied:

    • Previous studies on the insulating ability of insulating materials

    • Existing methods for comparing the actual heating needs of existing buildings

    • Calculation methods for theoretical heating needs, structural strength and building-related physics

    • Swedish climate conditions and Swedish requirements for buildings

    The study has shown that previous research on true insulating ability is lacking and that previous comparisons of insulating ability do not take actual conditions into account. Furthermore, the study has found an absence of existing methods for comparing the actual insulation capacity of existing buildings. Verified methods for assessing the actual energy use of buildings, in combination with the energy calculation method, have been used to create a method for comparing the actual heating needs of existing buildings. Finally, an experimental proposal with a test module has been designed. The design includes drawings, design requirements and expected energy requirements for two different insulation materials.The conclusion is that there is a theoretical need to study the actual insulating ability of insulating materials, and that studying the heating requirements of experimental modules is the most appropriate method for investigating real insulating ability.

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  • 27.
    El Halabi, Philip
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Holm, Joel
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Experimentdesign för jämförelse av isoleringsmaterials teoretiska och verkliga isoleringsförmåga2019Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    In recent decades, the increasing requirements of energy use in buildings have resulted in a demand for more well-insulated and airtight structures. The theoretical insulation capacity of an insulating material is determined during tests performed in a laboratory environment. The problem is that these conditions differ significantly from real conditions.

    The purpose of this thesis is to investigate the U-value of insulating materials in real conditions. The thesis does not include execution of experiments. Furthermore, the study is limited to Swedish conditions and two insulation materials: polyurethane and mineral wool. For this purpose, two problem statements have been formulated:

    •What is the need for testing insulating material’s true insulating abilities?

    •Which method is more suitable for examining insulating material's true insulating ability, studying the heating needs of existing buildings or experiment modules?

    The study was based on literature studies where the following information and data were studied:

    •Previous studies on the insulating ability of insulating materials

    •Existing methods for comparing the actual heating needs of existing buildings

    •Calculation methods for theoretical heating needs, structural strength and building-related physics

    •Swedish climate conditions and Swedish requirements for buildings

    The study has shown that previous research on true insulating ability is lacking and that previous comparisons of insulating ability do not take actual conditions into account. Furthermore, the study has found an absence of existing methods for comparing the actual insulation capacity of existing buildings. Verified methods for assessing the actual energy use of buildings, in combination with the energy calculation method, have been used to create a method for comparing the actual heating needs of existing buildings. Finally, an experimental proposal with a test module has been designed. The design includes drawings, design requirements and expected energy requirements for two different insulation materials.

    The conclusion is that there is a theoretical need to study the actual insulating ability of insulating materials, and that studying the heating requirements of experimental modules is the most appropriate method for investigating real insulating ability.   

  • 28.
    Englund, Jessika Steen
    et al.
    Univ Gavle, Sweden.
    Cehlin, Mathias
    Univ Gavle, Sweden.
    Akander, Jan
    Univ Gavle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Univ Gavle, Sweden.
    Measured and Simulated Energy Use in a Secondary School Building in Sweden: A Case Study of Validation, Airing, and Occupancy Behaviour2020In: Energies, E-ISSN 1996-1073, ENERGIES, Vol. 13, no 9, article id 2325Article in journal (Refereed)
    Abstract [en]

    In this case study, the energy performance of a secondary school building from the 1960s in Gavle, Sweden, was modelled in the building energy simulation (BES) tool IDA ICE version 4.8 prior to major renovation planning. The objectives of the study were to validate the BES model during both occupied and unoccupied periods, investigate how to model airing and varying occupancy behaviour, and finally investigate energy use to identify potential energy-efficiency measures. The BES model was validated by using field measurements and evidence-based input. Thermal bridges, infiltration, mechanical ventilation, domestic hot water circulation losses, and space heating power were calculated and measured. A backcasting method was developed to model heat losses due to airing, opening windows and doors, and other occupancy behaviour through regression analysis between daily heat power and outdoor temperature. Validation results show good agreement: 3.4% discrepancy between space heating measurements and simulations during an unoccupied week. Corresponding monthly discrepancy varied between 5.5% and 10.6% during three months with occupants. Annual simulation indicates that the best potential renovation measures are changing to efficient windows, improved envelope airtightness, new controls of the HVAC system, and increased external wall thermal insulation.

  • 29.
    Eriksson, Martin
    et al.
    Univ Gavle, Sweden.
    Akander, Jan
    Univ Gavle, Sweden.
    Moshfegh, Bahram
    Linköping University, Department of Management and Engineering, Energy Systems. Linköping University, Faculty of Science & Engineering. Univ Gavle, Sweden.
    Investigating Energy Use in a City District in Nordic Climate Using Energy Signature2022In: Energies, E-ISSN 1996-1073, Vol. 15, no 5, article id 1907Article in journal (Refereed)
    Abstract [en]

    This paper focuses on multi-family buildings in a Swedish city district, erected between 1965 and 1973, which are now in need of renovation. For the two types of multi-family buildings in the district, tower buildings and low-rise buildings, dynamic energy use is predicted by using an energy signature method. The energy signature is then used to calculate the primary energy use number of the building stock, according to calculations methods dictated by Swedish building regulations. These regulations are also used to assess which multi-family buildings are in need of renovation, based on the buildings primary energy use. For buildings that need energy renovations, it is simulated so that the energy use of each multi-family building complies with these same building regulations. The proposed methodology for simulating energy renovation also determines new energy signature parameters, related to building heat loss coefficient, balance temperature and domestic hot water usage. The effects of simulated renovation are displayed in a duration diagram, revealing how a large-scale renovation affects the districts heat load in different annual periods, which affects the local district heating system. Sensitivity analysis is also performed before and after simulated energy renovation.

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  • 30.
    Eriksson, Per-Erik
    et al.
    Sveriges Tekniska Forskningsinstitut, Hållbar samhällsbyggnad.
    Nord, Tomas
    Linköping University, Department of Management and Engineering, Industrial Economics. Linköping University, Faculty of Science & Engineering.
    Östman, Birgit
    Sveriges Tekniska Forskningsinstitut, Hållbar samhällsbyggnad.
    Kartläggning av brandincidener i flervåningshus med trästomme: Erfarenhet av 20 års brukande2016Report (Other academic)
    Abstract [en]

    The analysis in this project shows that modern multi-story wooden buildings for housing exhibit a lower fire incident rate than the rest of the multi-family housing stock. This is not surprising since the studied buildings are relatively new. Only one of the incidents in the total of more than 10,000 homes have any connection to the structural material.

    In recent years, the question of fire safety of modern wood construction has been raised from new perspectives. The applied technology for 20 years has been based on the fire safety requirements in the national building code (based on EU:s Construction Products Directive), largely validated through laboratory tests. When the construction technology is now recognized and is expected to increase significantly, the requirement for an evaluation of its function in the real world comes from many actors. This report presents the experiences from built projects in use.

    Modern wood construction is defined in this project as apartment buildings higher than two storeys, where the load-bearing structural material is wood, according to the revised Swedish building regulations in 1994 or later versions. All apartment buildings, including student housing and assisted living, have been included. The project has completed and analysed a total inventory of these homes.

    Data has been collected directly from the component manufacturing companies, developers and contractors who manufactured and erected apartment buildings with more than two stories since 1994. The Swedish Civil Contingencies Agency (MSB) has delivered extracts from its incident database of fire incidents for all of these buildings.

    Data is thus available on more than 10,000 apartments from 188 construction project, which is estimated to represent more than 95 % of completed projects. Respondents in the industry is reporting a total of 3 cases of fire incidents for the years from 1998 to 2014 and the MSB data expands the number with minor incidents to a total of 22 cases for these years, three of which were in separate garbage buildings.

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  • 31.
    Eriksson, Sara
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Reslan, Sara
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Practical study to prevent collapse against earthquakes2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Indonesien ligger i Indiska Oceanen och består av ett flertal öar. Landet ligger nära stora tektoniska plattor som tenderar att röra på sig. Det är därför en väldigt stor risk att jordbävningar inträffar i Indonesien. I dagsläget vet man inte varför plattorna rör på sig eller när det kommer att ske.Jordbävningar av hög kaliber är sällsynta och det är praktiskt omöjligt att dimensionera byggnader mot sådana skalv. När konstruktioner tas fram för att bygga jordbävningsresistent är grundidén att byggnader ska tåla måttliga skalv. För att undersöka hur byggnationen ser ut i Indonesien utfördes fältundersökningar samt ett volontärarbete på plats genom organisationen Green Lion. Studien syftar till att hitta enkla lösningar för att få en mer jordbävningsresistent byggnad. För att en byggnad ska ha en stor chans att klara sig måste material med bra töjningsegenskaper användas, armering av stål har sådana egenskaper. En annan viktig åtgärd är att bygga konstruktionen sammanhängande så att de olika elementen stöttar upp varandra när byggnaden utsätts för krafter.

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  • 32.
    Frick, Jesper
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Osman, Aweys Mohamed
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Homebuyers choices and valuations2015Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Det finns en generellt god kunskap inom byggnadsbranschen om vilka lägen och byggnadsformer som värderas högst hos bostadsköpare i Sverige. Byggnadsbranschen har dock inte lika bra kunskaper om vad som är att föredra inom bostaden i fråga eftersom dessa värderingar ändrar sig snabbt med tiden. Vilka värderingar har egentligen bostadsköpare när det kommer till bostadens konstruktion, funktionalitet och utformning? Svaret på denna fråga skulle gynna både företagen och bostadsköpare. Syftet med denna studie är just att besvara denna fråga med begränsning till flerbostadshus. Syftet är också att ta reda på hur konstruktionslösningar på en högre nivå än standard påverkar bostadsköparens vilja att betala mer för bostaden. Examensarbetet bygger på en förfrågan av Botrygg AB som vill veta mer om vad bostadsköpare har för värderingar och vilka val de gör om de kan påverka bostaden. För att uppfylla syftet har en kvantitativ studie genomförts där resultatet baseras på en enkätundersökning. Enkäten bestod av tydligt formulerade fleralternativs frågor där den svarande fick värdera olika påståenden och konstruktionslösningar. För att skapa enkäten har en djupare litteraturstudie genomförts. Enkäten visar en mängd intressanta resultat bland annat att bostadsköpare gärna har möjlighet att påverka sin framtida bostad, vare sig det handlar om innan de flyttat in eller efter. Bostadens utformning och planlösning är viktigare än bostadsytan och priset, där det även är tydligt att en öppen eller halvöppen planlösning är att föredra. Det viktigaste med bostadens kök är att det är utformat med fokus på arbetsyta och förvaring. Konstruktionslösningar med högre nivå än standard ökar generellt viljan att betala mer för bostaden, men eftersom svaren skiljer sig mycket handlar det mer om att hitta rätt köpare än en lösning som passar alla. De svarande uttrycker också att det som de är mest nöjda med i sin nuvarande bostad är att den är genomförd med hög konstruktionskvalitet.

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  • 33.
    Fällman, Alexander
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Yngve, Max
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Passive house year round2015Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Passivhus är idag populära bostäder med tyngdpunkt på låg energianvändning. En kravspecifikation, FEBY 12, ställer ett flertal krav på passivhus, däribland energianvändning för uppvärmning. Ett välisolerat och tätt klimatskal är därför en förutsättning för passivhuset att kunna uppfylla kraven. Denna rapport behandlar fönster, som är en del av klimatskalet, och dess påverkan på det termiska inomhusklimatet. Studien genomfördes genom simuleringar i datorprogrammet ParaSol. I det första steget jämfördes fönsterarea, g-värde, u-värde, orientering samt geografisk plats för att undersöka hur energianvändningen förändrades. Resultateten presenteras med diagram och i ett senare avsnitt även slutsatser. Detta tillämpas med ett exempelhus som placeras i Lund, Stockholm och Luleå. Med hjälp av fönsterareor och fönsteregenskaper optimeras energianvändningen för uppvärmningen så att husen uppfyller kraven i FEBY 12. Fönsterareornas storlek behöver anpassas till den geografiska positionen för att uppnå en optimal energianvändning för uppvärmning. I studien fick vi fram att fönsterareorna, utan solavskärmning, i Lund kunde utgöra 16 % av fasaden, i Stockholm 13 % av fasaden och i Luleå 11 % av fasaden. Med solavskärmning blev fönsterareorna något större, detta medförde också en något större energiförbrukning.

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  • 34.
    Glad, Wiktoria
    Linköping University, Department of Thematic Studies, Technology and Social Change. Linköping University, Faculty of Arts and Sciences.
    Everyday governance of energy systems2017In: International High-Performance Built Environment Conference – A Sustainable Built Environment Conference 2016 Series (SBE16), iHBE 2016 / [ed] Lan Ding; Francesco Fiorito; Paul Osmond, Elsevier, 2017, Vol. 180, p. 1612-1621Conference paper (Refereed)
    Abstract [en]

    The proposed transition to a low-carbon society faces challenges, as it is occurring too slowly to achieve the goals set by international and national governmental bodies, and gaps are found between available energy-efficiency technologies and their appropriate use. The governance of domestic energy systems has attracted European research attention, and the findings illustrate how materials, competence, and meaning influence energy productivity in domestic settings and how accountability is enacted by connecting people and technologies. The present research cites Swedish examples of how energy efficiency has been improved by involving multiple local actors, such as consumers, energy utilities, property companies, and local governments. Examples are analysed through the lens of social change and mundane governance theory, illustrating how spaces and places often overlooked as too mundane to be considered in policy prove, when analysed in more detail, to be important for energy efficiency. The results indicate that “governance pairs” (e.g., “households/lighting” and “caretakers/heating systems”) are more or less successfully held together and influence accountability and governance possibilities. The present analyses demonstrate that, while governance is often portrayed in terms of causality, everyday practices involving governance pairs are messier and less predictable than anticipated. These results call for the upgrading of research into everyday life and for bottom–up approaches to energy studies. Accountability – crucial to closing the energy-efficiency gap and understood in the context of mundane governance – can advance our energy-efficiency thinking and action.

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  • 35.
    Grenzfurtner, Wolfgang
    et al.
    Universität Bayreuth.
    Mayhofer, Richard
    Universität für Bodenkultur Wien (BOKU).
    Rudberg, Martin
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Gronalt, Manfred
    Universität für Bodenkultur Wien (BOKU).
    Performance management systems and practices in an industrialised housebuilding on-site context : identifying improvement potential through a qualitative study2019In: 26th International EurOMA Conference 2019: Operations adding value to society , 17.-19.06.2019 , Helsinki, Finland., 2019Conference paper (Other academic)
    Abstract [en]

    High wastage rates and unsatisfactory performance gains affect on-site working for industrialised housebuilding (IHB) production. Rarely used performance management systems (PMS) are often quoted as one obstacle to support systematic productivity and efficiency improvements. To prepare the field for the development of an informative PMS a multiple case study is carried out, in order to show the potential on applied performance management systems. The three cases show diversified application of performance management (PM), ranging from various performance indicators used for management decisions to almost ignoring generated measures. Different approaches in developing PMS for the identified corporate strategies are analysed.

  • 36.
    Grenzfurtner, Wolfgang
    et al.
    Universität Bayreuth.
    Rudberg, Martin
    Linköping University, Department of Science and Technology, Communications and Transport Systems.
    Gronalt, Manfred
    Universität für Bodenkultur Wien (BOKU).
    Collaboration in performance management across industrialised housebuilding supply chains2021In: Logistics Research Network (LRN) Conference 2021: Sustainable and resilient supply chains in disruptive times , 08.-10. Sept. 2021 , Cardiff, UK., 2021Conference paper (Other academic)
    Abstract [en]

    PurposeProduction on the construction site usually takes place through the cooperation of several companies working together in assembling building components and fulfilling craft works. The goal of involved companies is the successful completion of their own contribution to generate a positive contribution margin. Good coordination and collaboration within the supply chain (SC) is necessary to minimise inefficiencies and to systematically improve on-site processes. Measuring and evaluating performance within the construction SC and sharing data and information will thus be an important basis for improvement activities. The purpose of this research is to investigate how performance measurement and management (PMM) collaboration is organised between industrialised housebuilding (IHB) companies and their subcontractors.Research approachA multiple case study was conducted within the IHB sector. Data collection was conducted through qualitative interviews and the data was analysed with thematic coding and content analysis.Findings and OriginalityIn the area of quality, data on defects and non-conformities is exchanged between companies in all SCs via construction site reports. However, none of the IHB companies use these data to systematically measure performance indicators. The data on defects and non-conformities are applied to assess the quality of execution of the trades on site. This data is used from those IHB companies which produce highly customised buildings, with the aim of evaluating the performance of its subcontractors. Qualitative feedback has been identified as the predominant information used for improving quality attributes. In the area of productivity, the predominant indicator shared within the SC is the fulfilment of a given schedule. The identification of inefficiencies at interfaces between SC partners is currently not considered. Especially in this area, there is a need to improve PMM in order to increase the productivity and profitability of the companies involved within the IHB SC.Research ImpactThe main contribution of this paper is that it analyses the current state of collaboration within IHB SCs in the area of PMM of on-site production. In addition, best practice approaches are described.Practical ImpactManagers can use the findings to identify weaknesses within areas of their responsibility of IHB SC’s.

  • 37.
    Gustafsson, Lena
    Linköping University, Department of Science and Technology.
    Rostskyddssystem för stålprofiler: Tekniska egenskaper, ekonomi och miljöfrågor2004Independent thesis Basic level (professional degree)Student thesis
    Abstract [sv]

    Nästan alla stålkonstruktioner måste rostskyddas. Undantaget är de som står inomhus i torr luft. Ett rostskydd kan utföras på flera olika sätt, men de vanligaste är att stålet målas med rostskyddsfärg eller att det varmförzinkas. Innan detta kan utföras måste stålet förbehandlas. Det är viktigt att den utförs noggrant för annars kan kvarvarande föroreningar börja rosta under färg- eller zinkskiktet. Rapporten behandlar de ovan nämnda metoderna, dess egenskaper och miljöpåverkan samt kostnader för systemen.

    De rostskyddsmetoder som används har alla en negativ påverkan på naturen och hälsan. Hur stor den är beror på vilken sorts beläggning som används. Men man måste också tänka på att de faktiskt skyddar stålet och ökar livslängden och därigenom ger ett bättre resursutnyttjande.

    Att säga hur mycket ett system kostar är inte helt lätt. Dessa kostnader beror på flera saker. Den största skillnaden gör mängden stål, men det beror även på till exempel tjocklek och typ av skikt.

    Resultatet av studien är ett antal tabeller där konstruktörerna själva kan gå in och välja det system som, med tanke på ekonomi och miljöfrågor samt skiktets egenskaper, passar bäst till konstruktionen. Även ett snabbvalssystem har utvecklats där man väljer enbart efter en kategori, till exempel den billigaste eller den starkaste.

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  • 38.
    Gustavsson, Adam
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Öberg, Olof
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Cellulosaisolering eller konventionell isolering: En jämförelse utifrån miljö- och kostnadsperspektiv mellan cellulosaisolering, mineralull och cellplast2021Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    This paper is written as a thesis project at Linköping University. The environment is one of the main issues in society today, and the construction industry must contribute as well, in order to achieve sustainability. Insulation is an essential part when building a house, and the production process often demands a high amount of raw material and energy. Therefore it is important to choose the kind of insulation which makes as little impact on the environment as possible. In addition to the environment, there are other important aspects to consider as well. How the materials can withstand moisture in different ways, how they react in case of a fire and what the cost is to purchase and install. The purpose of this paper is to compare the two most common insulation materials today, mineral wool and expanded polystyrene, with cellulose insulation, which is often marketed as a more environmentally friendly alternative, and find out which type of insulation is the best, based on these aspects. The paper is written as a review study of previous papers, literature on the subject and information from manufacturers and trade organizations. The main parts of the paper consist of the third chapter Teori which describes the different insulation materials, and the fourth chapter Empiri which describes the fire and moisture properties, environmental impact and cost of the materials. The result of the paper is that mineral wool is the best insulation material for walls in most cases. Mineral wool is the cheapest, has good fire properties and has the lowest carbon dioxide emissions of the compared board materials. Cellulose insulation can be a good alternative from an environmental standpoint as it is possible to recycle instead of depositing, but in that case you should choose loose fill insulation which is made from circulated newspapers. Expanded polystyrene is not recommended as insulation for walls as it has the highest carbon dioxide emissions and has poor fire properties.

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  • 39.
    Hagman, Oliver
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Johansson, Erik
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, The Institute of Technology.
    Dimensioning aids for nail and screw joints2015Independent thesis Basic level (university diploma), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    I Sverige idag används trä som byggnadsmaterial i stor utsträckning, 90 % av alla enfamiljshus som byggs idag är byggda med trämaterial. Vid sammanfogning av olika träelement används olika förbandstyper. Förbanden som används idag är: Spikförband, Skruvförband, Träskruvförband, Tandbrickor, Spikplåt Syftet med arbetet är att undersöka möjligheten, samt att skapa ett dimensioneringshjälpmedel för träförband som kan underlätta dimensioneringsgången. En genomgång hur beräkningsgången ser ut enligt Eurokod 5 som är den rådande standarden för dimensionering av träförband. Arbetet kommer undersöka hur det olika parametrarna som ingår i dimensioneringsberäkningarna påverkar förbandets tvärkraftsbärförmåga. Tester har utförts på förband med förbindare av räfflad trådspik och laskar av trä. Enligt testerna visade det sig att det enskäriga förbandet hade en högre tvärkraftsbärförmåga än vad det tvåskäriga förbandet, i det fallet då man utformar det enskäriga förbandet med laskar på båda sidorna och har en förskjutning av förbindarna sinsemellan. Den parameter som påverkar tvärkraftsbärförmågan i beräkningsformlerna enligt Eurokod 5 har efter undersökning kommit fram till att det är spikens diameter som ger störst utslag på den dimensionerande tvärkraftsbärförmågan för förbandet.

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  • 40.
    Hassan, Osama
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A Simplified Procedure to Determine the Deflection of Statically Indeterminate Structures2014In: International Journal of Aerospace and Lightweight Structures, ISSN 2010-4286, Vol. 4, no 4, p. 241-253Article in journal (Refereed)
    Abstract [en]

    In the study presented here, the problem of calculating deflection of stati-cally indeterminate continuous beams and structural frames is addressed. Theelastic line equation, taught in many standard courses in structural mechan-ics is used to determine the structure deflections.In the investigated method,the structure is divided into a simply supported members in which the elas-tic line equation is applied to calculate the deflection shape of the structure.The results are compared with the finite element method (FEM) and goodagreement is obtained. Moreover, the advantage of this method is that it issimplified, general, not time-consuming, and it can be standardised to thistype of structures.

  • 41.
    Hassan, Osama
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    A simplified structural analysis of statically indeterminate continuous thick beams2016In: International Journal of Mechanical Engineering Education, ISSN 0306-4190, E-ISSN 2050-4586, ISSN 0306-4190, Vol. 44, no 4, p. 257-271Article in journal (Refereed)
    Abstract [en]

    In the study presented here, a simplified exact analytical solution of the problem of indeterminate continuous beams is derived and compared with the numerical solution, finite element. For the analytical method, the structure is divided into a simply supported element with internal support moments. The moments are first calculated with the help of boundary rotation conditions by taking into account both the shear andbending deformations. Second, the deflection functions of the beam members are derived. The results of a two-span continuous beam show that both methods yield an excellent agreement. The advantage of the presented method is that it is simplified, general, not time-consuming, and it can be standardized to this type of structures. Solution methods discussed in this paper can be of interest within the framework of mechanical and civil engineering education in which bending and shear of thick beamsare taught.

  • 42.
    Hassan, Osama
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Effect of wooden floorboards on the vibration of timber floor2024In: Scientific Reports, E-ISSN 2045-2322, Vol. 14, no 1, article id 779Article in journal (Other academic)
    Abstract [en]

    This study is aimed at investigating those parameters related to timber fooring that can afect the acceptability of vibration behaviour of a timber foor in a residential building in view of the criteria stated in Eurocode EC5. The timber foor investigated is made of OSB/3 foorboards and timber joists. The parameters that are investigated in this study are thickness of fooring, foor joist span, joist spacing and connection of foorboards to the joists. In this context, two cases are considered. First: the fooring is nailed or screwed to the joists and no composite action or interaction is obtained between joists and foorboards. Second: the fooring is glued sufciently to the joists and full interaction is obtained. The result suggests that glued foorboards perform much better with respect to natural frequency, static defection and peak foor velocity than nailed or screwed foorboards. In almost all cases of glued foorboards, the result complies fully with the Eurocode 5 design vibration requirements. However, as foor lengths increase, the static defection will increase beyond the allowable limit, especially for relatively thin foor panels and relatively widely spread joists. For both cases, increasing foorboards thickness and decreasing the joist span by adding more beams can yield even better results to satisfy the requirement of vibration comfort.

  • 43.
    Hassan, Osama
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    On the structural stability of timber members to EurocodeIn: Mechanics based design of structures and machines, ISSN 1539-7734, E-ISSN 1539-7742Article in journal (Refereed)
    Abstract [en]

    This study investigates the load-bearing behaviour of timber members subjected to combined compression and bending based on the guidelines of the standard Eurocode 5. In this context, two design approaches are stated to account for flexural buckling: the effective length method and the second-order analysis. Although Eurocode 5 states that second-order analysis can be carried out to check the stability of beam-columns, it does not mention how to formulate this analysis. This study investigates this case in order to develop alternative interaction formulae to check the stability of timber members subjected to simultaneously acting axial compression and bending moments with risk of buckling failure. Firstly, expressions are derived to formulate the interaction formulae based on second-order analysis. Secondly, the derivedinteraction formulae are compared with Eurocode 5 formulation. A parametric study is carried out to compare the two methods and the differences between results are discussed. The second-order analysis advanced in this paper can be an alternative tool to be used by the structural engineer to assess the stability of axially loaded members subjected to the risk of flexural buckling failure.

  • 44.
    Hassan, Osama
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    On the structural stability of timber members to Eurocode2019In: Mechanics based design of structures and machines, ISSN 1539-7734, E-ISSN 1539-7742, Vol. 47, no 5, p. 647-657Article in journal (Refereed)
    Abstract [en]

    This study investigates the load-bearing behavior of timber members subjected to combined compression and bending based on the guidelines of the standard Eurocode 5. In this context, two design approaches are stated to account for flexural buckling: the effective length method and the second-order analysis. Although Eurocode 5 states that second-order analysis can be carried out to check the stability of beam-columns, it does not mention how to formulate this analysis. This study investigates this case in order to develop alternative interaction formulae to check the stability of timber members subjected to simultaneously acting axial compression and bending moments with risk of buckling failure. The second-order analysis advanced in this article can be an alternative tool to be used by the structural engineer to assess the stability of axially loaded members subjected to the risk of flexural buckling failure. Communicated by Francisco Javier Gonzalez Varela.

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  • 45.
    Hassan, Osama
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Practical expressions to calculate the main vertical actions on load-bearing columns/walls to Eurocode2017In: Journal of Engineering, Design and Technology, ISSN 1726-0531, E-ISSN 1758-8901, Vol. 15, no 7, p. 418-435Article in journal (Refereed)
    Abstract [en]

    Purpose – The aim of this review study is to present useful and practical expressions to compute the design vertical actions on load-bearing columns/walls of typical building structures on the basis of EN 1991: Eurocode 1.

    Design/methodology/approach – It is derived by a typical case in which wind actions, snow actions and permanents actions are loading a roof construction. The results are finally used to calculate the loading on columns/walls. Both ultimate limit state and serviceability limit state are considered.

    Findings – From an instructive point of view, the advantage of this method is that it is simplified, general, not time-consuming, and it can be standardised to typical building structures.

    Research limitations/implications – A number of example applications are introduced to illustrate the calculation procedure.

    Practical implications – From an educational point of view, this problem is of interest to civil engineering students because the reviewed method is not cumbersome or time-consuming.

    Social implications – From an engineering educational point of view, this problem is of interest to civil engineering students because the reviewed method is not cumbersome or time-consuming.

    Originality/value – New formulated expressions to calculate the loadings on structural membranes based on Eurocode are presented.

  • 46.
    Hassan, Osama
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    The effect of flexural–torsional buckling on the stability of timber members: a case study2021In: SN Applied Sciences, ISSN 2523-3963, E-ISSN 2523-3971, Vol. 3, no 6, article id 619Article in journal (Refereed)
    Abstract [en]

    This study investigates the stability of timber members subjected to simultaneously acting axial compression and bending moment, with possible risk for torsional and flexural–torsional buckling. This situation can occur in laterally supported members where one side of the member is braced but the other side is unbraced. In this case, the free side will buckle out of plane while the braced side will be prevented from torsional and flexural–torsional buckling. This problem can be evident for long members in timber-frame structures, which are subjected to high axial compression combined with bending moments in which the member is not sufficiently braced at both sides. This study is based on the design requirement stated in Eurocode 5. Solution methods discussed in this paper can be of interest within the framework of structural and building Engineering practices and education in which the stability of structural elements is investigated.

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  • 47.
    Hassan, Osama A.B.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Effect of foundation designs of passive house on the thermal bridges at the ground2016In: Journal of Engineering, Design and Technology, ISSN 1726-0531, E-ISSN 1758-8901, Vol. 14, no 4, p. 602-613Article in journal (Refereed)
    Abstract [en]

    In this paper it is attempted to study the effect of different foundation designs of passive house on the resultant thermal bridges, at the junction between a wall and a slab on grade. The linear thermal transmittances of some newly developed foundations of passive house are determined. The compared foundation designs are L-element, U-element and foundation with foam glass technique. It is found that the special design of passive house foundation can considerably influence the heat flow through thermal bridges. The calculated linear thermaltransmittances of L-element, U- element and foundation with foam glass are 0.085 W/mK, 0.074 W/mK and 0.031 W/mK, respectively. In this context, it is proposed a new foundation design of passive house, which has relatively low heat loss through thermal bridges, calculated as 0.031 W/mK. The results are compared with the “default” ISO values used to evaluate the effect of thermal bridges in typical buildings. It is found that there is large difference between the calculated linear thermal transmittances at the investigated foundationsof passive house as compared to typical buildings.

  • 48.
    Hassan, Osama
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Christopher, Johansson
    Byggprojektering, WSP Sverige AB, Linköping, Sweden.
    Glued laminated timber and steel beams: A comparative study of structural design, economic and environmental consequences2018In: Journal of Engineering, Design and Technology, ISSN 1726-0531, E-ISSN 1758-8901, Vol. 16, no 3, p. 398-417Article in journal (Refereed)
    Abstract [en]

    Purpose – This paper compares glued laminated timber and steel beams with respect to structural design, manufacturing and assembly costs, and the amount of greenhouse gas emissions.

    Design/methodology/approach – This paper presents structural design requirements in conformance with EN 1993: Eurocode 5 and Eurocode 3. With the help of these standards, expressions are derived to evaluate the design criteria of the beams. Based on the results of life-cycle analysis, the economic properties and environmental impact of the two types of beam are investigated. In this paper, the effect of beam span on the design values, costs and carbon dioxide emissions is analyzed when investigating aspects of the structural design, economy and environmental impact. Different cross-sections are chosen for this purpose.

    Findings – The study shows that the glued laminated (abbreviated as glulam”) beams have a smaller tendency to lateral torsional buckling than the steel beams, and that they can be cheaper. From an environmental point of view, glulam beams are the more environmentally friendly option of the two beam materials. Furthermore, glulam beams may have a direct positive effect on the environment, considering the carbon-storage capacity of the wood. The disadvantage of glued wood is that larger dimensions are sometimes required.

    Research limitations/implications – Wind load and the effect of second-order effects have not been considered when analysing the static design. Only straight beams have been studied. Furthermore, the dynamic design of the beams has not been investigated, and the bearing pressure capacity of the supports has not been analyzed. We have investigated timber beams with a rectangular cross-section, and steel beams of rolled I-sections, known as “HEA profiles”. The cost analysis is based mainly on the manufacturing and assembly costs prevalent on the Swedish market. The only environmental impact investigated has been the emission of greenhouse gases. The design calculations are based on the European standards Eurocode 5 and Eurocode 3.

    Practical implications – To achieve sustainability in construction engineering, it is important to study the environmental and economic consequences of the building elements. By combining these two effects with the technical design of buildings made of steel and/or timber, the concept of sustainable development can be achieved in the long run.

     Social implications – The study concerns sustainability of building structures, which is an important of the sustainable development of the society.

     Originality/value – The paper contains new information, and will be useful to researchers and civil engineers.

  • 49.
    Hassan, Osama
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Emad, Nour
    WSP Sverige AB, Norrkoping, Sweden.
    Gabriel, Abdulahad
    AFRY AB, Norrkoping, Sweden.
    A comparative study between glulam and concrete columns in view of design, economy and environment2022In: Case Studies in Construction Materials, E-ISSN 2214-5095, Vol. 16, article id e00966Article in journal (Refereed)
    Abstract [en]

    In this paper, it is attempted to study possible sustainability solutions for building structures. In this context, comparisons are made between two load-bearing columns with different building materials – glued laminated timber and concrete – with regard to structural design, economic consequences and the emission of greenhouse gases. In terms of structural design, the results show that with small axial forces, glulam columns will result in smaller cross-sectional areas compared to concrete columns. However, at larger axial forces, concrete columns will result in smaller cross-sectional areas than glulam columns. An increased column length also means larger dimensions for glulam columns, but this does not always apply to concrete columns. With respect to environmental impact, it is shown that using glulam columns is the more environmentally friendly option. From an economic point of view, the cost estimates for glulam and concrete columns may vary depending on the country and the abundance of the construction material. In Sweden, a forest-rich country, it is shown that the costs for both column types are quite similar considering small axial loads. At higher axial loading, concrete is generally the cheaper alternative.

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  • 50.
    Hassan, Osama
    et al.
    Linköping University, Department of Science and Technology, Communications and Transport Systems. Linköping University, Faculty of Science & Engineering.
    Rezaie, Hamid
    Val av bärande system ur hållbara byggnaders perspektiv, en fallstudie2022In: Bygg och Teknik, ISSN 0281-658X, E-ISSN 2002-8350, Vol. 114, no 6, p. 55-57Article in journal (Other academic)
    Abstract [sv]

    Syftet med artikeln är att studera hur valet av bärande system kan påverka mängden av betong och armering som används i grundläggning och dess inverkan på ekonomin och miljöfaktorer. 

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