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  • 301.
    Mohr, Dirk
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Gary, Gerard
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Lundberg, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Evaluation of stress-strain curve estimates in dynamic experiments2010In: International Journal of Impact Engineering, ISSN 0734-743X, E-ISSN 1879-3509, Vol. 37, no 2, p. 161-169Article in journal (Refereed)
    Abstract [en]

    Accurate measurements of the forces and velocities at the boundaries of a dynamically loaded specimen may be obtained using split Hopkinson pressure bars (SHPB) or other experimental devices. However, the determination of a representative stress-strain curve based on these measurements can be challenging. Due to transient effects, the stress and strain fields are not uniform within the specimen. Several formulas have been proposed in the past to estimate the stress-strain curve from dynamic experiments. Here, we make use of the theoretical solution for the waves in an elastic specimen to evaluate the accuracy of these estimates. it is found that it is important to avoid an artificial time shift in the processing of the experimental data. Moreover, it is concluded that the combination of the output force based stress estimate and the average strain provides the best of the commonly used stress-strain curve estimates in standard SHPB experiments.

  • 302.
    Molin Mårtensson, Marcus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Informationsöverföring mellan konstruktionsprogram: Användbarheten av ISM vid synkronisering av data mellan AECOsim Building Designer och Tekla Structures2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Information transfer between structural design programs

    This report examines whether the synchronization tool ISM is useful for structural engineers when transferring structural data between structural design programs AECOsim Building Designer and Tekla Structures.

    The report is written in collaboration with Byggnadstekniska Byrån, who see the need to streamline the modeling process. In their present workflow, a constructional object is modeled separately in AECOsim Building Designer and Tekla Structures. The time required for modeling can be reduced if ISM can be used to transfer a model from one program to another.

    The utility of ISM is decided from certain evaluation criteria. Each criterion represents data of a constructional component that is controlled for correct synchronization. The information consists of the component profile name, geometry, coordinates, material quality and fire class.

    The implementation of the evaluation follows a specific workflow, where various steel and concrete components are synchronized between the structural design programs. The component data is controlled and documented in four steps. Further, it is determined whether the data is judged to be correct or not.

    The result show synchronized building components that do not meet the mandatory evaluation criteria. For synchronization of structures containing building components of steel, the unfulfilled criteria leads to certain limitations in the technology. However, with a few adjustments to the designer modeling techniques, ISM can be useful in the synchronization of structures in concrete.

  • 303.
    Monie, Svante
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Nilsson, Annica
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Åberg, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Electricity balancing capacity, emissions, and cost comparison of three storage-based local energy systems for variable power generation2019In: 9th International Workshop on Integration of Solar Power and Storage into Power Systems, 2019Conference paper (Other academic)
    Abstract [en]

    This study compares three energy system setups for supplying the electricity and heat demand in a residential area. Two of the setups contain district heating and a combined heat and power unit. The first setup contains a thermal storage and the second contains an electric battery. The third setup is all electric (incl. the heat production). The second setup reduced the electricity balancing demand the most, but had the highest CO2,eq-emissions. The third setup had no emissions, but the highest cost. This setup also increased the balancing demand. The first system, with the thermal storage, performed most satisfying when electricity balancing capacity, CO2,eq-emissions, and costs were weighed together.

  • 304.
    Mousavi, Saed
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid Mechanics.
    Hillström, Lars
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Lundberg, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Solid Mechanics.
    Identification of complex shear modulus from measured shear strains on a circular disc subjected to transient torsion at its centre2008In: Journal of Sound and Vibration, ISSN 0022-460X, E-ISSN 1095-8568, Vol. 313, no 3-5, p. 567-580Article in journal (Refereed)
    Abstract [en]

    A method for identification of complex shear modulus from measured shear strains on a circular disc subjected to a transient torque at its centre has been established. It is based on the evolution of an outgoing shear wave between two radial positions at which the associated shear strains are measured. The two-dimensional shear wave solutions used are exact in the sense of three-dimensional theory. Therefore, in principle, there is no frequency beyond which they are not valid. The method requires a minimum disc size, which is related to the duration of the load. The non-parametric results become inaccurate at frequencies near zero and at certain problematic frequencies where the excitation of the disc is weak or non-existent. These frequencies may be moved outside the frequency range of interest by sufficiently decreasing the duration of the load. If there are problematic frequencies within this range, the results of parametric identification become more accurate than those of non-parametric identification. Parametric results from experimental tests with loads having different amplitudes and durations agree well with each other in accord with the assumed linearity of the tested polypropylene material.

  • 305.
    Muzamal, Muhammad
    et al.
    Chalmers, Dept Chem & Chem Engn, Gothenburg, Sweden..
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Rasmuson, Anders
    Chalmers, Dept Chem & Chem Engn, Gothenburg, Sweden..
    Mechanistic study of microstructural deformation and stress in steam-exploded softwood2017In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 51, no 3, p. 447-462Article in journal (Refereed)
    Abstract [en]

    Steam explosion pretreatment results in the formation of microcracks in the cell walls of wood. In the present study, steam explosion experiments were performed and structural changes in Norway spruce were identified using scanning electron microscopy. The cellular structure of the softwood spruce was simulated using the finite element method, and the effects of pressure generated during the steam explosion pretreatment on the deformation of the cells were investigated. The simulated model included earlywood, latewood, and ray cells. The effects of bordered and cross-field pits on the stresses in the cell wall were studied as well. Many similarities were observed between the microcracks in the steam-exploded wood and the high-stress regions predicted by the model. The experimental and simulation results showed that the radial cell walls in the earlywood cells experienced major deformation. The presence of the pits created stress localization and facilitated the formation of microcracks in the cell walls.

  • 306. Muzamal, Muhammad
    et al.
    Gamstedt, E Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Rasmuson, Anders
    Modeling wood fiber deformation caused by vapor expansion during steam explosion of wood2014In: Wood Science and Technology, ISSN 0043-7719, E-ISSN 1432-5225, Vol. 48, no 2, p. 353-372Article in journal (Refereed)
    Abstract [en]

    Steam explosion is a process used to enhance enzyme penetration and digestibility of wood. Wood chips are processed with high-pressure steam for a limited time, and the bonding between polysaccharides and lignin is weakened. After this processing, the pressure is rapidly reduced to induce steam explosion where the vapor inside a fiber expands and exerts pressure on the fiber walls. This pressure causes fiber deformation and breakage. In this study, fiber deformation caused by vapor expansion was simulated by single wood fibers using finite element modeling. When pressure is applied inside a fiber, it is likely to break from the corner and midway between two adjacent corners. The fiber is modeled with four layers (P, S1, S2, and S3). Although the P, S1, and S3 layers are very thin, they significantly prevent fiber deformation. The fibers with a thin wall and a low micro-fibril angle (MFA) deform more than the fibers with a thick wall and a higher MFA. It was found that the shape of the fiber plays an important role in its deformation. The areas of localized strain are the most likely places for fiber splitting. Essentially, fiber wall damage is more likely to occur in (1) thin-walled fibers, i.e., earlywood, (2) fibers with damaged P and S1 layers, (3) fibers with low MFAs, and (4) fibers with irregular cross-sections. Different chemical pretreatments, fractionation procedures, and selections of raw materials can accordingly be considered to produce easily steam-exploded materials.

  • 307.
    Möllerberg, Erik
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Tingelöf, Gustav
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Intern kommunikation inom uppdragsprocessen2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Projects in the construction sector, whether it is of newconstructions or renovations, is a process that includes severaldisciplines that must interact. To facilitate collaborationthere are many different methods and tools for communication. Thisreport aims to create an understanding of the problems thatBjerking, a consulting company in the construction design sector,today has with the internal communication, or if there even isa problem, and to examine solutions to improve communication. Inorder to obtain data, Bjerking employees from Uppsala and Stockholmwere interviewed and a customer who has a far-reaching frameworkagreement with Bjerking. A survey was also sent out to all450 employees at Bjerking. Other secondary data on groupdevelopment, interviewing techniques and more were obtained inliterature through the network library Legimus and the databaseDiva. The results of interviews and the survey show that there isa problem with how communication takes place and that there is adissatisfaction with the handling of documents. The presentedproposals for improvements are based on the shortcomings that existin the communication that emerged in the interview study and thesurvey. These proposals include third-party file management andchatbased communication systems. They will influence how dailycommunication and internal communication within projects take place.This in turn can affect the project’s quality and timeconsumtion.Although Bjerking already has a communication tool, it isprimarily the project that decides on how the work should be done.However, one should be consistent in the choice of communicationtools internally. Proposals for a minor restructuring of thetemplates and control documents presented on Bjerking’s intranetare presented. Proposals concerning project numbering and access todocuments aswell.Finally, recommendations and further studies are presented whereconcrete proposals about which communication system is best suitedto Bjerking and what the next step to increase the efficiency is.

  • 308. Neagu, R Cristian
    et al.
    Bertolla, LucaBoissard, Carole I RBerthold, FredrikBourban, Pierre-EtienneGamstedt, E KristoferUppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.Månson, Jan-Anders E
    Novel biodegradable wood fibre/polylactic acid foam sandwich composites2011Conference proceedings (editor) (Refereed)
  • 309.
    Neagu, R. Cristian
    et al.
    Laboratoire de Technologie des Composites et Polymères (LTC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Schweiz.
    Cuenoud, Matthieu
    Laboratoire de Technologie des Composites et Polymères (LTC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Schweiz.
    Berthold, Fredrik
    New Materials and Composites, INNVENTIA AB, Stockholm.
    Bourban, Pierre-Etienne
    Laboratoire de Technologie des Composites et Polymères (LTC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Schweiz.
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Lindstrom, Mikael
    New materials and Composites, INNVENTIA AB, Stockholm.
    Månson, Jan-Anders E.
    Laboratoire de Technologie des Composites et Polymères (LTC), Ecole Polytechnique Fédérale de Lausanne (EPFL), Schweiz.
    The potential of wood fibers as reinforcement in cellular biopolymers2012In: Journal of cellular plastics (Print), ISSN 0021-955X, E-ISSN 1530-7999, Vol. 48, no 1, p. 71-103Article in journal (Refereed)
    Abstract [en]

    Wood fiber-reinforced polylactic acid composite foams have been successfully produced using supercritical carbon dioxide. The addition of fibers had a strong effect on microstructure of the foams. An increase in wood fiber content implied smaller average cell size and higher average cell wall thickness as estimated from image analysis of scanning electron microscopy micrographs. Addition of 10 wt% wood fibers seemed to be a limit to obtain foams, with the used processing conditions. The stiffness properties of the foams in compression improved upon addition of wood fibers. A significant increase of specific stiffness was achieved by adding 5-10 wt% wood fibers. It was shown that the stiffness was about 50% higher in the transverse direction for reinforced foams. The strength in the transverse direction increased for foams with unmodified wood fibers but decreased for foams with two types of treated wood fibers as compared with the strength of the pure polylactic acid foam of similar density. A butyl tetracarboxylic acid treatment followed by an additional surfactant treatment results in reduced wood fiber network-forming ability and reduced fiber-matrix adhesion. This contributes to the inferior observed strength properties in this study. The experimental stiffness was comparable with a superposed micromechanical model for a three-phase fiber-reinforced foam. The model shows that increasing the relative density, that is, the ratio of the density of the foam to the density of the composite material, by adding wood fibers results in a noteworthy increase in the transverse compression stiffness of the foams but only at relative density values above 0.2 for the used processing conditions in this study. The key factor for reinforcement is the relation between foam relative density and fiber volume fraction in the preform. The foaming conditions have to be adapted for each wood fiber content to obtain foams with the desired relative density.

  • 310.
    Netterstedt, Carl
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    LÅGTEMPERERAD LUFTBUREN VÄRME OCH BYGGNADSINTEGRERAD FÖRNYBAR ENERGIUTVINNING  I HÅLLBARA ÖSTRA SALA BACKE, UPPSALA2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Uppsala kommun har beslutat att bebygga området Östra Sala backe, beläget mellan Gränby i norr och Boländerna och Fyrislund i söder. Markanvisning har givits byggherrar för första etappen och byggandet beräknas starta 2013. Området är tänkt att ha en hållbarhetsprofil. Detta arbete undersöker delar av den framtida energianvändningen med utgångspunkt från första etappens planerade byggnader. Huvudfrågorna för arbetet har varit följande:

    Går det ur lågtempererad fjärrvärme att utvinna tillräckligt med energi för att täcka värmebehovet med ett luftburet system? Vilka alternativ finns avseende utvinning av förnybar energi integrerat i byggnader och hur utnyttjas dessa mest effektivt? Examensarbetet är utfört i samråd med Arne Roos och Magnus Åberg vid Institutionen för teknikvetenskaper, Fasta tillståndets fysik, Uppsala universitet.

    Examensarbetet innehåller en bakgrundsbeskrivning, beräkning av temperatur hos tilluft vid luftburen uppvärmning och elproduktion hos småskaliga vindkraftverk, och simuleringar av dels luftburen uppvärmning med olika fjärrvärmetemperaturer och dels byggnader med solfångare och solceller.

    Beräkningarna visade att flödet, som blir högre för större byggnader, hade stor inverkan på vilken temperatur tilluften behövdes värmas till. Simuleringarna med olika fjärrvärmetemperaturer indikerade att lågtempererade fjärrvärme ställer väldigt höga krav på ett luftburet uppvärmningssystem. Vidare gav simuleringarna med solfångare resultatet att värmebehovet minskar relativt sett kraftigast för små anläggningar för att sedan succesivt avtar i förhållande till ökad storlek. Solcellsimuleringarna gav utfallet att elproduktion blir liten i förhållande till förbrukningen för framförallt stora byggnader. Beräkningarna med småskaliga vindkraftverk gav en ännu mindre elproduktion.

    Slutsatserna från examensarbetet är att för att använda sig av luftburen värme bör fjärrvärmen vara av normal temperatur. Solenergi bidrar i högre utsträckning än vindkraft till att sänka energiförbrukningen för byggnader. Det är av stor vikt att storleken på solfångar- eller solcellsanläggningen noga väljs för att effektivast utnyttja värme- eller elproduktionen.

  • 311.
    Nilsson, Helena
    et al.
    Wallenberg Wood Science Center KTH, Stockholm.
    Galland, Sylvain
    Wallenberg Wood Science Center KTH, Stockholm.
    Larsson, Per Tomas
    Wallenberg Wood Science Center KTH, Stockholm.
    Gamstedt, E. Kristofer
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Iversen, Tommy
    Wallenberg Wood Science Center KTH, Stockholm.
    Compression molded wood pulp biocomposites: a study of hemicellulose influence on cellulose supramolecular structure and material properties2012In: Cellulose (London), ISSN 0969-0239, E-ISSN 1572-882X, Vol. 19, no 3, p. 751-760Article in journal (Refereed)
    Abstract [en]

    In this study, the importance of hemicellulose content and structure in chemical pulps on the property relationships in compression molded wood pulp biocomposites is examined. Three different softwood pulps are compared; an acid sulfite dissolving grade pulp with high cellulose purity, an acid sulfite paper grade pulp and a paper grade kraft pulp, the latter two both containing higher amounts of hemicelluloses. Biocomposites based the acid sulfite pulps exhibit twice as high Young's modulus as the composite based on paper grade kraft pulp, 11-12 and 6 GPa, respectively, and the explanation is most likely the difference in beating response of the pulps. Also the water retention value (WRV) is similarly low for the two molded sulfite pulps (0.5 g/g) as compared to the molded kraft pulp (0.9 g/g). The carbohydrate composition is determined by neutral sugar analysis and average molar masses by SEC. The cellulose supramolecular structure (cellulose fibril aggregation) is studied by solid state CP/MAS C-13-NMR and two forms of hemicellulose are assigned. During compression molding, cellulose fibril aggregation occurs to higher extent in the acid sulfite pulps as compared to the kraft pulp. In conclusion, the most important observation from this study is that the difference in hemicellulose content and structure seems to affect the aggregation behaviour and WRV of the investigated biocomposites.

  • 312.
    Nilsson, Jonas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Forsberg, Anton
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    UTFACKNINGSVÄGGAR: En studie i ekonomi och tid2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Infill walls is a proven method of constructing a buildings envelope that is the layer separating the outer environment from the inner. Infill walls are generally made of steel, wood or reinforced concrete. Regardless of its material structure, the infill wall is a non-bearing wall with the sole purpose of closing a buildings perimeter and supporting, in addition to its own weight, also that of the cladding.

     

    The company cooperating in this report is currently managing projects in Uppsala where infill walls are the primary choice for outer wall constructions. However, these infill walls can either be built on site or ordered as prefabricated, without clear preference. When choosing a method of infill walling the main concerns are economy, logistics and working environment. This gave birth to the idea of comparing these methods of infill walling to try and determine which method is most suitable for a certain type of project, focusing on the aspects of economy, logistics and time consummation. The approach of the comparison, and the study as a whole, has primarily been conducted as field observations and interviews to various extent. In addition to field-related work, invoices and production schedules of each project has been studied in an attempt to obtain as much information on costs and time consuming activities related to the infill walls as possible. The total costs, including pure material costs and wages, divided by the area of each studied infill wall, results in a cost per square meter infill wall. Similarly, a capacity per hour is calculated by dividing the area of each studied infill wall by the sum of the calculated expenditure of time. The calculated parameters allow for an objective comparison between the two different methods of infill walling. Furthermore, the aspects that are not directly connected to time and economy can be evaluated subjectively to obtain an extensive view of the work related to infill walls.

     

    The results of the comparison indicates that prefabricated infill walls are a faster, but somewhat more expensive, way of constructing outer walls than on-site built. The purchase price related to on-site built infill walls is a great deal lower than that related to prefabricated. However, the capacity of on-site built infill walls is more than 4 times lower than prefabricated, which means that the definitive cost per square meter is merely 4,1 % lower for on-site built infill walls than that of the prefabricated.

  • 313.
    Nilsson Strand, Rasmus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Dimensionering av betongbeläggning för flygfält2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    There is at present a lack of guidelines for the design of concrete pavements for airfields and thus a need to prepare these. The purpose of this study is to describe the Swedish design principles for the design of both unreinforced concrete slabs joined with dowels and continuously reinforced concrete slabs for use in pavements for airfields and to develop design templates for these types of pavements. This report will also serve as a guideline in design and also provide suggestions on the dimensions of unreinforced concrete slabs joined with dowels and continuously reinforced concrete slabs and the underlying soil layers.

     

    This thesis deals with the design of unreinforced concrete slabs joined with dowels and continuously reinforced concrete slabs as pavements for airfields designed for airplanes of the largest class of airplane, code F. The complete pavement is from top to bottom: concrete slabs, bound base of asphalt bound gravel, unbound base and subbase on terraced subgrade.

    In the report, the main focus is the examination of the exhaustion of the concrete, the bound base and subbase. That is to say how many times airplanes can run over these pavements before failure occurs. Exhaustion is dependent on temperature tensions caused by the seasonal varying temperature gradient through the concrete and tension caused by traffic loads.

    For the bound base and subbase strain of the materials because of the tensions are checked.

    Actual design of pavements is done in the form of a case study of the design of concrete pavements for airfields for a reference project. The design is based on the Swedish method for the design of concrete roads with established literature. Stresses and strains due to traffic loads are calculated using FEM program PLAXIS.

    The design assumes that the unreinforced concrete slabs joined with dowels will be completely uncracked. These will therefore have to be significantly thicker than the reinforced plates.

    The reinforced pavements need to meet certain requirements. These pavements will have to be able to handle the moment load, have a required maximum distance between cracks and minimum reinforcement requirements.

    The report is arranged in such a way that the readers themselves easily will be able to establish and develop templates for fatigue calculation with the use of suitable software. No matter in which way the template is designed the intention will be to automate the use of the formulas that are mentioned and numbered in the report.

  • 314. Norbakhsh, Shahin
    et al.
    Bjurhager, Ingela
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Almkvist, Gunnar
    Impact of iron(II) and oxygen on degradation of oak - modeling of the Vasa wood2014In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 68, no 6, p. 649-655Article in journal (Refereed)
    Abstract [en]

    In the wood of the Swedish 17th century warship Vasa, iron (Fe)-catalyzed chemical degradation has taken place after the salvation in 1961, which is manifested in increased acidity accompanied by cellulose degradation and reduced strength in the oak hull. Model studies on fresh oak impregnated with Fe(II) also led to tensile strength (TS) reduction in the same order of magnitude as observed in the wood of the Vasa. In the present study, further experiments have been performed concerning the Fe-catalyzed wood degradation. Namely, the degree of wood degradation was monitored quantitatively by measurement of the O-2 consumption of Fe(II)-impregnated oak, kept in closed vials with different relative humidities (RH), as a function of time. The initial O-2 consumption was high and declined with time. After 200 days, the accumulated O-2 consumption was 0.3-0.4 mmol g(-1) wood. Degradation products with low molecular weight were analyzed. The release of CO2 and oxalic acid (OA) was positively correlated with RH (0.235 and 0.044 mmol g(-1), respectively, at RH98% after 200 days). Samples kept for 1500 days at RH54% had accumulated 0.044 mmol OA g(-1) wood, which is equal to the average OA content in the interior of Vasa oak (corresponding to 4 mg g(-1)). Oak samples, from which extractives had been removed prior to Fe(II) impregnation, did not change their O-2 consumption or TS reduction compared to the nonextracted samples, indicating that extractives are not essential for cellulose degradation in this context.

  • 315. Norbakhsh, Shahin
    et al.
    Bjurhager, Ingela
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Almkvist, Gunnar
    Mimicking of the strength loss in the Vasa: model experiments with iron-impregnated recent oak2013In: Holzforschung, ISSN 0018-3830, E-ISSN 1437-434X, Vol. 67, no 6, p. 707-714Article in journal (Refereed)
    Abstract [en]

    Previous studies of the oak wood of the 17th century warship the Vasa have shown significant changes in the chemical and mechanical properties compared with recent oak. The most important factors contributing to these changes are the incorporation of iron compounds during waterlogging and the uptake of polyethylene glycol (PEG) in the course of the 17 years of preservation treatment. To investigate the effect of iron-dependent oxidative degradation reactions, recent oak wood samples were impregnated with aqueous iron(II) chloride solution (0.1 M) and thereafter exposed to air or pure oxygen at controlled relative humidity in long-term experiments followed by tensile strength (TS) measurements. The iron-impregnated samples exposed to oxygen displayed significant effects already after 1 week and the reduction in TS was similar to 50% after 1 year. The samples treated with additional PEG displayed less TS reduction, whereas the addition of cysteine had no effect. The size exclusion chromatography of treated samples showed that the average molecular weight of holocellulose had decreased. The results confirm that iron compounds have a detrimental effect in wood and indicate that PEG might act as an antioxidant for the degradation processes. Concerning the Vasa, it may be concluded that most degradation related to iron compounds and oxidative processes have taken place during the first period of conservation when the wood was exposed to oxygen in a still very humid state. Thus, the current rate of oxidative degradation under the present relatively dry museum conditions should be relatively low.

  • 316.
    Norberg, Sara
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Sawasa, Hadeel
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Inverkan av alkalisilikareaktion (ASR) på lamelldammars bärförmåga2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Dams are an important structure in Sweden and around the world regarding water supply, regulation of flows and power generation. An expansion due to an alkalisilicareaction (ASR) in a concrete dam can lead to many problems. Among other things it may cause leakage of water, and problems with opening and closing of gates.

    A lot of research has been done to find out how ASR affects the strength and load carrying capacity of concrete. This thesis aims, through a literature review, to show how the load carrying capacity of a buttress dam is influenced by an alkalisilicareaction. The first part describes what a buttress dam is and principles for the design of a monolith. The second part shows how ASR occurs and what the reaction could result in. It also shows ways to inhibit the reaction. The third part displays a way to investigate and estimate the damage of ASR in a buttress dam. The fourth section shows how ASR affects the strength of unreinforced concrete and the load carrying capacity of a reinforced structure.

    The results show that while the unreinforced concrete strength is greatly affected by ASR the resistance of a buttress is not affected to the same extent. However, this is provided that the dam is sufficiently reinforced with longitudinal reinforcement in both directions and that shear reinforcement are present. This also applies only if the expansion in the concrete is low to moderate.

  • 317. Nordgren, N.
    et al.
    Sandell, R.Berthold, F.Pettersson, T.Gamstedt, KristoferUppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Characterization of interfacial stress transferability of particulate cellulose composite materials2012Conference proceedings (editor) (Refereed)
  • 318.
    Nordström, Henrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Malingsbo Herrgård: Energiberäkningar och åtgärdsförslag för en karolinsk 1700-talsgård2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Malingsbo Estate is a 18th century wooden building located in the small village of Malingsbo. Through the years, the estate has had a wide variation of usages. Today, almost 70 years since the last major renovation it is being utilized 6 weeks per year.

     

    The following report, which has been made possible with the cooperation with the National Property Board (Statens Fastighetsverk) seeks to answer the following four questions. 1: What is the current climate inside the building 2: What are the resident’s views on the climate and the status of the building. 3: suggestions on how to, with the current building increase the period in which the inside climate is suitable for living. 4: Suggestions for lowering the energy usage for the building. These four points seeks to be answered with the following method: reports from Statens Fastighetsverk, surveys, field excursions and simulations in VIP-Energy.

     

    The result of this report which should be especially considered is the following: At present time with no heating in the building, residents feel the climate during July to be acceptable to good, while during October most thinks it is to cold. For increasing the duration where the building meets a temperature of 20 degrees Celsius to 24 weeks’ installations of a 12500 W heating system is needed. For lowering the energy consumption without making large changes to the building two options should be specially considered: Insulation in the foundation with 50 mm insulation, and installation of window shutters during week 45 to 10. A larger installation suitable is solar panels for heating.

  • 319.
    Norin, Max
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Uttorkning av högpresterande betonggolv: Råd och rekommendationer vid mätning av RF2017Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A development project was undertaken within the consortia formed by Polygon and AK-konsult. The aim of this project was to map out the impact of humidity leakages on the result of humidity measurements in concrete slabs according to the so-called RBK-method. It is behind the idea of this development project that the main purpose of this thesis can be derived from. For instance, an evaluation of already existing data material from a RBK-measurement has been done. A method has been retrieved in order to compare the trend of the measured values of the relative humidity with the trend of the expected values of the relative humidity during the drying process. The main goal has been to implement this method as an instrument to analyze the actual drying process.

    A survey study was undertaken among the employees of the consortia in order to point out the differences that arise during the installation of the measurement equipment prior to measurement according to the RBK-method. The result of the survey has been summarized and analyzed in purpose to catch a wider glimpse over the different kinds of variables that might have an impact on the result from a RBK-measurement.

    The outcome from the study of the existing measurement data shows that some of the measurement spots tends to dry out faster than the calculated drying process, while other spots indicates a slower drying process. Three of them actually pointed out that they were under humidity, which implies that they still hadn’t reached the stadium of moisture equilibrium with the concrete. The main reason behind the observed discrepancies might have its explanation in the fact that measurement wholes that have been subjected to a big humidity leakage. The consequence of measurement spots subjected to big humidity leakages, is that the measured value of the relative humidity turns out to be much lower than the actual level of the relative humidity in the concrete.

    An observation has been made in the plausibility analysis and in the Vaisalaproject that the normative equilibrium time exceeds the number of three days that’s been ordained by RBK. A further study of the normative equilibrium time can thereby be recommended to clarify if it still can be compatible with the different kinds of concrete classes of today.

  • 320.
    Norlander, Hans
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Automatic control.
    Valdek, Urmas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Lundberg, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Söderström, Torsten
    Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Division of Systems and Control. Uppsala University, Disciplinary Domain of Science and Technology, Mathematics and Computer Science, Department of Information Technology, Automatic control.
    Parameter estimation from wave propagation tests on a tube perforated by helical slots2013In: Mechanical systems and signal processing, ISSN 0888-3270, E-ISSN 1096-1216, Vol. 40, no 1, p. 385-399Article in journal (Refereed)
    Abstract [en]

    For a tube with doubly symmetric cross section and perforations by helical slots there is a coupling between extension and torsion. In this paper a one dimensional (1D) model structure for a tube with such a helical slot segment (HSS) is established, and parameters accounting for the coupling between extension and torsion are estimated from wave propagation experiments. In these experiments incident extensional waves were generated through axial impact by strikers of different lengths, causing reflected and transmitted waves of extensional and torsional type which were measured in terms of surface strains on either side of the HSS part of the tube. A statistical test on the experimental data shows that the output residuals (the difference between modeled and experimental output) cannot be explained by measurement noise alone. This is not surprising since the 1D model structure is based on some simplifying assumptions concerning the geometry of the HSS. Parameters for two different geometries of the HSS are estimated, and the models are assessed in terms of model fa, simulations and wave energy distribution. It turns out that for one case, where the geometrical assumptions are valid, the 1D model is adequate, while for another case, where the validity of the assumptions is questionable, it is not. It is concluded that the 1D model structure provides a simple and efficient description of the HSS if the geometrical assumptions are valid.

  • 321.
    Norrlander, Pontus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    ALTERNATIVA ASFALTSBELÄGGNINGAR: Möjligheten att använda icke petroleumbaserade bindemedel2012Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report investigates the possibility to use non-petroleum based adhesive (biobitumen) in asphalt. The main reasons for replacing bitumen are the fact that oil prices are rising, the threat of peak oil and the fact that the asphalt industry is becoming more environmentally friendly.

    The main purpose of this report is to investigate whether there are any non-petroleum based adhesives on the market. If so, how can they be used? The questions covered are:

    • Are there any other alternative asphalt coatings available?

    • Can bio-oils be used in asphalt?

    • If the bio-oils can be used, what are the details their properties?

    • How does a cold climate affect the bio binders?

    • What is the Swedish asphalt industry’s opinion about bio asphalt?

    The project was concluded through literature studies, consultations with people in the asphalt industry and through several interviews.

    The conclusion of this report is that there are some existing non-petroleum based adhesives on the market. They are mainly used for bike paths, sidewalks and parkareas. The biggest problem for greater use is the fact that it is expensive and performance in cold climate is unknown. The study indicates that Sweden could have a new potential industry in the field of producing bio-adhesives from both wood and waste from paper industry

  • 322.
    Nylander, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Kungsängslerans krypsättning: Analys av dess storleksordning och krypparametrar samt förslag på lämplig beräkningsmetod2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Kungsängen, a central area in Uppsala of Sweden, has a considerable depth of clay which stretches down to 100 m at some sites. In order to build at this type of soil one has to take long-term settlements into consideration, such as consolidation and creep. However, methods for calculating the latter aren’t straight forward since the mathematics behind the process is complicated. The starting time of creep is still unsettled and this is also the case regarding calculation methods. In order to enhance the understanding of creep of Kungsängen clay this study was developed in collaboration with Bjerking AB.

    Altimetry data from studs and fixed points from Kungsängen was compiled and the results showed that buildings in Kungsängen are experiencing creep even though some of them were built 80–170 years ago. The mean value of relative creep was found to be 0,134 per mille/year for the stud data and 0,067 per mille/year for fixed points. Another finding was that time and depth of clay were two factors behind the creep of Kungsängen clay.

    Another aim of the study was to investigate creep calculations methods in Eurocode 7. However, it was found that no method was proposed in the standard and therefore some other methods such as the time resistant theory and the Chalmer’s model with creep were investigated. It was found that the time resistant theory predicted creep realistically but with an overestimation in some cases, depending on the type of clay. Some clay specimen gave a negligible creep for loads under 45 kPa and other specimen indicated otherwise. All in all, this suggests that the time resistant theory might be an appropriate creep calculation method for the clay of Kungsängen. The Chalmer’s model with creep overestimated the total deformation but underestimated the creep when modelling odometer loads. Even so, the study of the model was not detailed enough in order to reject it or not. Therefore, a more detailed study of the model should be considered.

  • 323.
    Nyström Vaara, Tobias
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Effektivare sprickbreddsberäkning för böjda och dragna betongtvärsnitt2015Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis describes how the crack widths of concrete structures is calculated, according to current standards. Special focus has been placed on how the cross-sectional analysis of bent cross- sections, with respect to the concrete's long-term effects, affects crack widths. Although the standard guide to the minimum amount reinforcement for crack control required for concrete structures with tensile stress are reported. The result is a calculation document drawn up in Excel that calculates crack widths for bent and drawn cross- section, which follows the requirements of the current standard. 

  • 324.
    Näslund, Linus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Överklagande och dess roll inom bostadsbyggandet: En granskning av plan- och bygglovsprocessen2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of this diploma work was to obtain a review of the appeal process in Sweden under the Planning and Building Act and the possibilities of appeal in the planning and building permit process. The work was intended to identify potential problems surrounding the appeal process and possible efficiency measures. The goal was to form a report that provides a satisfactory overview of the appeal process in theory and practical application as well as provide relevant concrete proposals on how the appeal process can be streamlined.

    Background and facts surrounding the work were taken from different types of literature and through several interviews with representatives in government, industry and politicians.

    The main problems related to the appeal process are in the long processing times and the high number of appeals. There is a great interest to streamline the appeals process and the government is going to launch studies in which possible future actions will be investigated.

    It is possible to appeal for up to two instances before you need a so called “leave to appeal” in order for your complaint to be passed on to the next instance. Appeals may be made for several reasons and in these instances of appeal there is no risk for either economic or legal sanctions for the complainant. The negligible risk in the appeal results in an exploitation of the appeal system.

    The introduction of an appeal fee may reduce the number of appeals. A fee may reduce the overuse and provide an effective appeals process and thus a more efficient planning and building permit process.

  • 325. Okrouhlik, M.
    et al.
    Ptak, S.
    Lundberg, Bengt
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Valdek, Urmas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    FE assessment of an experiment employed for analysis of the transient stress energy flux through spiral slots in axially impacted cylindrical tube2009In: Strojnicky Casopis, ISSN 0039-2472, Vol. 60, no 4, p. 181-209Article in journal (Refereed)
    Abstract [en]

    The temporal and spatial distribution of the stress wave energy flux in an axially impacted cylindrical tube, whose middle part contains four spiral slots, is studied experimentally and numerically. The high-speed recording of transient surface strains was used in the experiment, while the 3D finite element treatment was employed for the numerical analysis. The aim of the paper is to ascertain how reliable is the energy assessment based on transient recordings of surface strains and on subsequent 1D wave theory reasoning. The presented paper quantitatively determines how much of the impact energy, which is predominantly of axial (longitudinal) nature, is transferred into torsional (or shear) energy mode as well as to other energy modes not seen by the experiment.

  • 326.
    Okrouhlík, Miloslav
    et al.
    Institute of Thermomechanics.
    Pták, Svatopluk
    Institute of Thermomechanics.
    Valdek, Urmas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Self-Assessment of finite element solutions applied to transient phenomena in solid continuum mechanics2009In: Engineering mechanics, ISSN 1802-1484, Vol. 16, no 2, p. 103-121Article in journal (Refereed)
  • 327.
    Olsen, Lisa
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Vägen till GULD: En fallstudie av Rudbeck Lab 4 inför verifiering i Miljöbyggnad2016Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The number of certified buildings in Miljöbyggnad has highly increased during the last decade and today it is the most common environmental certification system in Sweden. A new building gets a preliminary certificate in Miljöbyggnad at first that has to be verified within two years after the building is put in use. Today, only a few buildings have been verified. Therefore the ones who are involved in a project that is going to be verified have to work in a new way in compare to a standard project.

    This thesis examines Rudbeck Lab 4 in order to identify how to ensure that the preliminary certification rating is achieved at verification. Which indicators that are the most critical have been identified and also a risk analysis of Rudbeck Lab 4's rating in Miljöbyggnad has been done.

    The most important aspects to examine to ensure that the preliminary certification rating is accomplished when verified are; everybody who is involved in the project's knowledge of Miljöbyggnad, the residents understanding of Miljöbyggnad, structured environmental meetings and clear requirements. It is particularly important to have Miljöbyggnad in mind during the whole project and to create a plan for how the verification is going to be done.

    The most critical indicator that has been identified is Energy usage. Solar Load,Thermal climate winter, Thermal climate summer and Daylight are indicators that also may need a particularly control before verification.

    Rudbeck Lab 4's chance to reach Miljöbyggnad GOLD is good. If the indicator Energy usage manage to achieve GOLD, the whole project should achieve the rating of GOLD.

  • 328.
    Olsson, Johan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Utvärdering av energiberäkningsprogram: Att användas i tidigt planeringsstadium för byggnader2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The regulations for energy consumption are consistently getting more and morestrict. This leads to a higher customer demand for energy analysis early in the buildingdesign process. Many building planners and architects use powerful modeling softwareto visualize their projects. These digital models contain sufficient information aboutthe building’s physical characteristics for reliable energy analysis. This report evaluatesthree different energy analysis software tools and their compatibility with themodeling software Autodesk Revit Architecture. The results in the report are basedon simulations made with a fictional model in the different tools. Some of the resultsobtained from the different programs are not consistent and because of the difficultiesin evaluating these differences the usefulness is limited. Based on several criteria thesoftware have been evaluated and a recommendation for the company Tema has beenproduced. Due to the complexity of energy analysis, the software requires certainpre-knowledge of the subject by the user to perform an accurate analysis. Inconclusion, the software which is best suited for preliminary energy analysis is,according to the author, VIP-Energy because of its efficiency and credibility.

  • 329. Oria, Carmela
    et al.
    Carrascal, I.
    Fernández, I.
    Ferreño, D.
    Afshar, Reza
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Gamstedt, K.
    Experimental and Numerical Analysis of Cellulosic Insulation Failures of Continuously Transposed Conductors under Short Circuits and Thermal Ageing in Power TransformersIn: IEEE transactions on dielectrics and electrical insulation, ISSN 1070-9878, E-ISSN 1558-4135Article in journal (Refereed)
    Abstract [en]

    The integrity of the cellulosic insulation in power transformers is considered one of the most relevant parameters that affects their performance and reliability. Electric faults, such as short circuits, have thermal and mechanical effects that degrade the paper and can eventually produce the end-of-life of the transformer. The evolution of the properties of the paper insulation of a commercial continuously transposed conductor due to thermal ageing was characterised through the degree of polymerisation and tensile testing. Failure initiation and propagation in the paper was analysed macroscopically and microscopically using scanning electron microscope. A finite element numerical mechanical model of the conductor was implemented to reproduce the experiments and to obtain the load level and strain state that produce failure at each ageing state, aiming at developing a failure model for the insulation. This model may contribute to an improvement in manufacturing processes and management of the electrical system.

  • 330.
    Oscarsson, Andreas
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Eklund, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Påbyggnad av våningsplan medlättkonstruktion: En jämförelse av stommaterialen trä ochtunnplåt2010Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to examinethe possibilities for adding a floor to anexisting building using the two materialswood and sheet metal profiles as the loadbearing structure. An apartment buildingfrom the 60s has been used as referencehouse. Two different suggestions for thedesign are presented in the rapport. Oneof them has been analyzed with wood andsheet metal as the load bearing structure.Using the old constructional calculationsand blueprints of the existing buildings,the load bearing capacity has beencalculated. In the calculation programFEM-Design the building has been testedwith the loads that an extra floor wouldgive. From this, a conclusion has beenmade whether the existing building couldmanage an extra floor. Using the 5-Dprogram Vico, a cost calculation has beenmade of the load bearing structure forboth materials. The costs have then beencompared and analyzed.

  • 331.
    Oskarsson, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Standardiserade produktionsmetoder: Ett lämpligt verktyg för erfarenhetsåterföring och produktionseffektivisering?2019Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis aims to contribute to increase Skanska Sweden's profitability on their construction sites by reducing the occurring waste. The thesis will examine if utilization of an already existing tool on Skanska Sweden’s intranet ”Standardiserade produktionsmetoder” [SPM] would help. SPM is described as a work preparation on a building component documented in a way so that people outside of the project can understand how the component was built and what resources were used during the process. SPM see no use today as there is a great lack of basic information available as well as a lacking knowledge that the tool exists at all. The foundation for a great asset exist, but in its present state it is barley to use.

    The current situation within the company as well as SPM’s present state and its potential has been determined with seven qualitative interviews performed on individuals with various roles. All of the informants shared the opinion that there’s room for improvement within the organization with experience feedback, they all also agreed that SPM have the potential to become a great way to share experiences between different projects. The conclusions in this report determine that SPM in an improved state could be a valuable asset to enable a more efficient production, entailed with other positive contributions to the construction sites and their coworkers. But there is a challenge ahead to get there, SPM relies on the contribution from active projects within Skanska. The company needs to found a commitment to that cause.

  • 332.
    Ousipov, Roni
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    MILJÖCERTIFIERINGSSYSTEMET MILJÖBYGGNAD I PRODUKTIONEN: En fördjupning inom området ”Material”2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The environmental assessment system Miljöbyggnad is a Swedish system initiated by Bygga-Bo-Dialogen to assess buildings with regards to three main areas; “Energy”, “Indoor climate” and “Materials”. A building can obtain three different classifications depending on how well it manages to meet the demands. GOLD is the highest classification and is followed by SILVER and BRONZE. The majority of the measures needed to comply with the demands are done during the design phase. During the production phase a considerable amount of work is required to make sure to document the built in products and make sure they do not contain any dangerous substances.

    The thesis is based on the experiences retrieved by working with Miljöbyggnad in Skanska’s project Sickla Udde skola which is aiming for the highest classification GOLD. Interviews have been conducted with employees of Skanska working with the system in order to take part of their experiences. The thesis identifies difficulties linked to working with the main area “Materials” during the production phase. It also describes the available product data bases used to simplify the work with the system. Furthermore the thesis gives suggestions on how to work with Miljöbyggnad during the production phase.

  • 333.
    Paavola, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Visuell planering enligt Lean: Optimering av samordning i syfte att höjakvaliteten i grundläggningsprojekt2015Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Construction production always contains different disciplines whose priorities andinterests can be very diverse. Good communication and coordination are essential tominimize misunderstandings and achieve good quality in the end result. This makesplanning a central part of the production management. In a world where conditionscan change as often as daily, being well prepared increases the opportunities to stayflexible and decrease negative effects of the changes.This study has been done in association with Skanska Foundations district North inStockholm in order to investigate how visual planning can be used in the productionmanagement to optimize the coordination and the quality.The history of Lean started at Toyota, but the concept are now spread over theworld and are used wide outside of the car industry nowadays. What’s challengingabout Lean in foundation projects is to embrace a long-term perspective and invest insolutions that are profitable in the longer term, instead of solve problems by onlytreating the symptoms.A holistic perspective is crucial in order to truly understand Lean. To study individualmethods and tools are against the core principals of Lean. However, due to thelimited time frame, this study has focused on the Lean concepts visual planning andgemba.Regardless of what kind of working methods the district chooses to use, it have tomake sure that every single employee understands the purpose and the benefitscoming with using that particular method. No change will work in the long termwithout a clear purpose.

  • 334.
    Pan, Ruijun
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Cheung, Ocean
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Wang, Zhaohui
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Tammela, Petter
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Huo, Jinxing
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Lindh, Jonas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Edström, Kristina
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Structural Chemistry.
    Strömme, Maria
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Nanotechnology and Functional Materials.
    Nyholm, Leif
    Uppsala University, Disciplinary Domain of Science and Technology, Chemistry, Department of Chemistry - Ångström, Inorganic Chemistry.
    Mesoporous Cladophora cellulose separators for lithium-ion batteries2016In: Journal of Power Sources, ISSN 0378-7753, E-ISSN 1873-2755, Vol. 321, p. 185-192Article in journal (Refereed)
    Abstract [en]

    Much effort is currently made to develop inexpensive and renewable materials which can replace the polyolefin microporous separators conventionally used in contemporary lithium-ion batteries. In the present work, it is demonstrated that mesoporous Cladophora cellulose (CC) separators constitute very promising alternatives based on their high crystallinity, good thermal stability and straightforward manufacturing. The CC separators, which are fabricated using an undemanding paper-making like process involving vacuum filtration, have a typical thickness of about 35 mu m, an average pore size of about 20 nm, a Young's modulus of 5.9 GPa and also exhibit an ionic conductivity of 0.4 mS cm(-1) after soaking with 1 M LiPF6 EC: DEC (1/1, v/v) electrolyte. The CC separators are demonstrated to be thermally stable at 150 degrees C and electrochemically inert in the potential range between 0 and 5 V vs. Li+/Li. A LiFePO4/Li cell containing a CC separator showed good cycling stability with 99.5% discharge capacity retention after 50 cycles at a rate of 0.2 C. These results indicate that the renewable CC separators are well-suited for use in high-performance lithium-ion batteries.

  • 335.
    Pennanen, Oskar
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik. Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Department of Art History, Conservation.
    Syed, Simon
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik. Uppsala University, Disciplinary Domain of Humanities and Social Sciences, Faculty of Arts, Department of Art History, Conservation.
    Social hållbarhet i renoveringsprocessen: En studie om hur dialog, jämställdhet och trygghet främjas vid ombyggnationer av bostäder2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report examines the correlation between social sustainability and the renovation process, focusing on the aspects; dialogue, gender equality and security. They were chosen after an interpretation of needs was done with help from a literature study. It concluded that the three chosen aspects were most beneficial to focus on from a socially sustainable perspective.

    Through interviews, a model of all stages of Uppsalahem's renovation process have been created to find opportunities for development with regard to the chosen aspects. The report begins with a comprehensive background description of today’s state and knowledge regarding renovation needs, social sustainability, civil dialogue and also an introduction of Uppsalahem. The main part of the report starts with an account of interviews in the form of a clarification of Uppsalahem's current renovation process. The main part also presents the results from a deeper literature study with regard to the selected aspects. In the final sections, the aspectsare linked to the renovation process, which then leads to conclusions summarized in the areas; renovation, dialogue,equality and security.

    The study has shown, among other things, that a neighbourhood security survey as a method of making the residential area more secure in association with the renovation can benefits theresidents. Housing company have also deemed to benefit by constructing a good dialogue.. It also appears that the action package is a progressive method that favors social sustainability,but is also a method with great development potential.

  • 336.
    Persson, Anton
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Sjelin, Martin
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Uppkomst av materialspill vid nyproduktion av flerbostadshus2014Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Construction waste from the housing industry includes all unnecessary consumption of building materials. The definition of construction waste is construction materials that has not been built in and becomes waste. Constructions waste can be divided into two types of contributions: operational and work site contribution. Some of the common construction materials in housing industry have such low usage level as 75 % and the rest becomes construction waste. Low usage of construction materials creates unnecessary costs and has a major environmental impact. Cost of the construction waste amounts 1-3 % of the total project cost.

    The purpose of this report was to identify causes for construction waste and suggest methods for prevention actions. The aim of this study was to highlight actions and approaches to reduce the quantity and volume of construction waste where possible. Methods used to fulfil the purpose of this thesis were analysis of literature, a case study and interviews. The report was made in collaboration with Nordic Construction Company, NCC, in Uppsala.

    Zero construction waste in housing industry is not realistic or desirable. The aim should be to optimize material usage based on the projects condition and in a first step try to minimize the work site contribution of construction waste.

  • 337. Persson, J.
    et al.
    Isaksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    A particle-based method for mechanical analyses of planar fiber-based materials2013In: International Journal for Numerical Methods in Engineering, ISSN 0029-5981, E-ISSN 1097-0207, Vol. 93, no 11, p. 1216-1234Article in journal (Refereed)
    Abstract [en]

    A new discrete element model to deal with rapid deformation and fracture of flat fibrous materials is derived. The method is based on classical mechanical theories and is a combination of traditional particle dynamics and nonlinear engineering beam theory. It is assumed that a fiber can be seen as a beam that is represented by discrete particles, which are moving according to Newton's laws of motion. Damage is dealt with by fracture of fiber-segments and fiberfiber bonds when the potential energy of a segment or bond exceeds the critical fracture energy. This allows fractures to evolve as a result of material properties only. To validate the model, four examples are shown and compared with analytical results found in literature.

  • 338. Persson, J.
    et al.
    Isaksson, PerUppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Dynamic fracture of thin 3D random fiber networks using a particle model2012Conference proceedings (editor) (Refereed)
  • 339. Persson, J.
    et al.
    Isaksson, PerUppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    High rate dynamic fracture of 3D random fiber networks using aparticle model2012Conference proceedings (editor) (Refereed)
  • 340. Persson, J.
    et al.
    Isaksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    Modeling rapidly growing cracks in planar materials with a view to micro structural effects2015In: International Journal of Fracture, ISSN 0376-9429, E-ISSN 1573-2673, Vol. 192, no 2, p. 191-201Article in journal (Refereed)
    Abstract [en]

    Dynamic fracture behavior in both fairly continuous materials and discontinuous cellular materials is analyzed using a hybrid particle model. It is illustrated that the model remarkably well captures the fracture behavior observed in experiments on fast growing cracks reported elsewhere. The material's microstructure is described through the configuration and connectivity of the particles and the model's sensitivity to a perturbation of the particle configuration is judged. In models describing a fairly homogeneous continuous material, the microstructure is represented by particles ordered in rectangular grids, while for models describing a discontinuous cellular material, the microstructure is represented by particles ordered in honeycomb grids having open cells. It is demonstrated that small random perturbations of the grid representing the microstructure results in scatter in the crack growth velocity. In materials with a continuous microstructure, the scatter in the global crack growth velocity is observable, but limited, and may explain the small scattering phenomenon observed in experiments on high-speed cracks in e.g. metals. A random perturbation of the initially ordered rectangular grid does however not change the average macroscopic crack growth velocity estimated from a set of models having different grid perturbations and imply that the microstructural discretization is of limited importance when predicting the global crack behavior in fairly continuous materials. On the other hand, it is shown that a similar perturbation of honeycomb grids, representing a material with a discontinuous cellular microstructure, result in a considerably larger scatter effect and there is also a clear shift towards higher crack growth velocities as the perturbation of the initially ordered grid become larger. Thus, capturing the discontinuous microstructure well is important when analyzing growing cracks in cellular or porous materials such as solid foams or wood.

  • 341. Persson, Johan
    et al.
    Isaksson, Per
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics.
    A mechanical particle model for analyzing rapid deformations and fracture in 3D fiber materials with ability to handle length effects2014In: International Journal of Solids and Structures, ISSN 0020-7683, E-ISSN 1879-2146, Vol. 51, no 11-12, p. 2244-2251Article in journal (Refereed)
    Abstract [en]

    A mechanical model for analyses of rapid deformation and fracture in three-dimensional fiber materials is derived. Large deformations and fractures are handled in a computationally efficient and robust way. The model is truly dynamic and computational time and memory demand scales linearly to the number of structural components, which make the model well suited for parallel computing. The specific advantages, compared to traditional continuous grid-based methods, are summarized as: (1) Nucleated cracks have no idealized continuous surfaces. (2) Specific macroscopic crack growth or path criteria are not needed. (3) The model explicitly considers failure processes at fiber scale and the influence on structural integrity is seamlessly considered. (4) No time consuming adaptive re-meshing is needed. The model is applied to simulate and analyze crack growth in random fiber networks with varying density of fibers. The results obtained in fracture zone analyses show that for sufficiently sparse networks, it is not possible to make predictions based on continuous material assumptions on a macroscopic scale. The limit lies near the connectivity l(c)/L = 0.1, where is the ratio between the average fiber segment length and the total fiber length. At ratios l(c)/L < 0.1 the network become denser and at the limit l(c)/L -> 0, a continuous continuum is approached on the macroscopic level.

  • 342.
    Persson, Staffan
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Indigenous Materials in Modern Buildings: for low energy houses in West Africa2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Burkina Faso is one of the poorest countries in the world. This landlocked country in the west has an extremely warm climate. Temperatures over 45°C are not uncommon and there is an almost constant need to keep the buildings cool to maintain a temperate indoor climate. Air-conditioning is an option to maintain the temperature but it overloads the power grid and only a few people can afford it. This thesis examines, through laboratory experiments, the thermal and mechanical properties that can be obtained by vibrating clayey soil and mixing it with water, lime or cement and organic fiber (Bissap). The report also examines different building projects utilizing local materials, both of a traditional and more modern nature.Energy required to produce building elements of soil is negligible compared to that of concrete and steel. Soil can be used in constructing houses but it is sensitive to water.The insulation is inadequate for a passive house so an extra layer of insulating material is required.The experiments performed during this project were inconclusive so it is impossible, from the results in this paper, to say if vibration is a good method for forming a building material of soil. The high water content needed, is however a major problem, shrinkage was about 20% and cracks were hard to avoid. Further investigations into the subject is necessary.

  • 343.
    Persäter, Jens
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Vinka, Amanda
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Anpassning av BIM-metodik för bättre mängdavtagning2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Byggnadsinformationsmodellering (BIM) är det informationshanteringssystem som de flesta konsultföretag och beställare strävar att implementera. Många har redan tillämpat BIM-metodiken som en del av byggprocessen. Eftersom tekniken går framåt tvingar detta också individen att utvecklas. Svårigheter uppstår när tekniken går framåt utan att den implementeras på rätt sätt av branschen. Problem finns i överföringen av information mellan olika parter. Ett av dessa problem är vid mängdavtagningar och kalkyler.

    Ett företag som ligger i framkant i utvecklingen och gärna vill effektivisera processen är Sweco Architects i Uppsala. De vill med hjälp av detta examensarbete undersöka beställarens krav och önskemål gällande kalkylering och mängdavtagning.

    Examensarbetets syfte är att med hjälp av en intervjustudie visa vad beställaren tycker behöver förändras och förbättras inom kalkylering och mängavtagningar från projektören.

    Målet med arbetet blir att med hjälp av intervjustudien ta fram en metodik till projektören som följer beställarens kravställning. Metodiken riktas in mot programvaran Autodesk Revit.

    Slutsatsen av arbetet är att en tydligare dialog mellan beställare och projektör behövs för att kunna förbättra mängdavtagningarna, men även en bättre arbetsmetodik för litterering. För att säkerställa detta bör en branschstandard upprättas men tills dess måste kravställningen bli tydligare.  

  • 344.
    Pettersson, Fredrik
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Tvärkraftsdimensionering av armerad betong: En utredning av beräkningsförfarandet2014Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report is about the shear force design of reinforced concrete according to Europe’s common dimension rules, Eurocode. The purpose is to describe the calculation procedure and the background to the formulas and expressions that occurs. Furthermore results from different calculation methods (hand calculations and computer calculations) will be compared to see how they differ.

    The goal with this is to go through the parts of Eurocode dealing with shear force and that this will lead to a clear review of these. You should also be able to see how results and the calculation procedure differ between different calculation methods. The reason of that is to see if it, in some cases, can be worth to spend some more time on calculations by hand.

    By the report you can see that, in many cases, the calculations made by hand leads to a smaller amount of shear reinforcement than the calculations in the computer programs. It may therefore be worth to calculate some designs by hand, especially since there was quite a difference in some cases. This is of course a judgment that has to be made for every single case by its own, since it takes considerably longer time to calculate a construction by hand than in a computer program.

  • 345.
    Pihl, Andreas
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    RENOVERING AV MILJONPROGRAMMET TILL PASSIVHUS: Implementering av tysk prefabteknik2009Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Construction accounts for about 35 percent of the total Swedish energy consumption and most of the energy is used by the large housing stock from the so-called “Million program”.

     

    In the national action plan the government has put forward in energy efficiency. It is mentioned that existing buildings account for more than 90 percent of what is expected to be the housing stock within the coming 50 years. In order to meet environmental objectives its required that the existing stock be reviewed for energy efficiency.

     

    The goverment is now initiating a national framework with a budget of SEK 300 million Swedish crowns per year for five years, starting in 2010 to achieve the goal on energy efficient buildings. Energy efficiency of buildings in both new construction and above all within the existing stock are addressed. In order to use this money as effectively as possible it is necessary to have a good plan, and adequate knowledge of minimizing energy use in the buildings will be done the possible way.

     

    In Germany, the use of Passive House technology have been successive and increases with steady pace. In Sweden we have not come as far. It is mainly in new production that the Passive House concept has been suitable in Germany, but it has also been proven that it is possible to refurbish buildings similar to the so-called Million program houses to Passive Houses. Prefabricated facade elements have been used to this puspose.

     

    This is a technology that is still unknown of in Sweden. It has good potential to be developed towards the industrialization of the prefabricated components aimed for the refurbishment of the Million program stock.

     

    Meanwhile Swedish contractors are waiting for results from a refurbishment project in the city of Alinsås, where buildings in the neighborhood Brogården were recently renovated with Passive House technology. The first measurement data will be available by the spring 2010. Alingsås has launched a starting point for the Swedish construction industry with a cencept that applies passive house technology?

     

    This work has studied how the construction industry looks at the refurbishment of the Million program stock to Passive Houses and wheater a smiliar concept as the one used in Germany with prefabricated facade elements are interesting for the Swedish market today. Literature study was carried out on the Passive House concept and on the German model. A series of interviews with various stakeholders from the construction industry was conducted.

     

    The findings are that there is not much interest to refurbish the stock of Million program towards Passive Houses. However, there is an interest for a large refurbishment towards low energy houses. In this concept, aspects of the Passive House concept are taken and adapted to the refurbishment towards low energy houses. The concept doesn´t take into account thermal briding and insulation of the ground floor, wich is considered to be too extesive and costly.

  • 346.
    Poulsen, Magnus
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Underhålls- och driftplanering inom Svenska kyrkan: Hur ser kontrollen ut hos en av Sveriges största fastighetsägare?2013Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This diploma work handles how some parishes of the Swedish Church administrate their building properties.The report also includes how some external property managers in Sweden work with maintenance plans and other maintenance issues. Further, a number of deficiencies have been identified and suggestions to workarounds are treated. The conclusions drawn in this thesis are based on the author´s experience in the field, performed interviews, and literature studies. The result of the work shows a general lack of knowledge in many parishes what concerns regulatory requirements, properties with no maintenance plan and substandard supervision resulting in unnecessary and expensive repairs. Based on these results, different plans for the maintenance of the building properties of the Swedish Church has been proposed.

  • 347.
    Psimopoulos, Emmanouil
    et al.
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences. Dalarna Univ, Energy Technol, Borlange, Sweden.
    Bee, Elena
    Univ Trento, Dept Civil Environm & Mech Engn, Trento, Italy.
    Widén, Joakim
    Uppsala University, Disciplinary Domain of Science and Technology, Technology, Department of Engineering Sciences, Applied Mechanics, Byggteknik.
    Bales, Chris
    Dalarna Un