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  • 1.
    Abdula, Sham
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oksman, Dan
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Attefallshus som komplementbostadshus: Drömhus eller mardröm?2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Den 2 juli 2014 blev det enligt lag tillåtet för en- och tvåbostadshusägare att uppföra en bygglovsbefriad komplementbyggnad på max 25 kvadratmeter på den egna fastigheten. Rapporten undersöker vilket genomslag lagändringen har haft i Stor-Stockholm, Stor-Göteborg och Stor-Malmö. Undersökningen visar att lagändringen ännu inte har haft något stort genomslag. I rapporten undersöks även en utvald del av marknadsaktörers utbud av attefallshus avsett som komplementbostadshus. 

    Ett attefallshus utformas med miljövänligt hållbara material och inspireras av Vitruvius tre principer för god arkitektur. Huset konstrueras med avsikt att uppfylla kraven som ställs i PBL, PBF, BBR och EKS. Målet med de framtagna bygghandlingarna är att få startbesked från byggnadsnämnden i Växjö. 

  • 2.
    Addassi, Mouadh
    et al.
    Technical University of Denmark, Denmark.
    Johannesson, Björn
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Wadsö, Lars
    Lund University.
    Inverse analyses of effective diffusion parameters relevant for a two-phase moisture model of cementitious materials2018In: Cement and Concrete Research, ISSN 0008-8846, E-ISSN 1873-3948, Vol. 106, p. 117-129Article in journal (Refereed)
    Abstract [en]

    Here we present an inverse analyses approach to determining the two-phase moisture transport properties re-levant to concrete durability modeling. The purposed moisture transport model was based on a continuumapproach with two truly separate equations for the liquid and gas phase being connected by the sorption ki-netics. The moisture properties of ten binder-systems containingfly ash, calcined clay, burnt shale and graymicro-filler, were investigated experimentally. The experiments used were, (i) sorption test (moisturefixation),(ii) cup test in two different relative humidity intervals, (iii) drying test, and, (iv) capillary suction test. Masschange over time, as obtained from the drying test, the two different cup test intervals and the capillary suctiontest, was used to obtain the effective diffusion parameters using the proposed inverse analyses approach. Themoisture properties obtained with the proposed inverse analyses method provide a good description of the testperiod for the ten different binder-systems.

  • 3.
    Aldarwash, Mustafa
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Bajqinca, Alban
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Nybyggnation av badrum : Jämförelse mellan prefabricerat och platsbyggt ur ett ekonomiskt perspektiv2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Syftet med arbetet är att, genom en ekonomisk undersökning skapa underlag som visar vilket alternativ av produktionsmetoderna prefabricerat eller platsbyggt badrum som är att föredra vid en nybyggnation av vårdhem. 

    Resultatet visar att det platsbyggda badrummet ger en ökad totalt kostnad på 627457 kr vilket motsvarar 11,1 procent dyrare än det prefabricerade badrummet. 

  • 4.
    Andersson, Jenny
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Malin, Enbom
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Hur ökas implementering av visuella arbetssätt inom Skanska?2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Visuella arbetssätt har visat sig vara effektivt inom byggbranschen. Studien omfattar de visuella arbetssätt som Skanska använder sig av; visuell styrning och visuell projektering. Syftet med studien är att öka antalet projekt som väljer att implementera arbetssätten. Därav har underliggande problem identifierats varför inte projekt väljer att implementera arbetssätten i den utsträckning som Skanska önskar.

    Det har visat sig under studiens gång att visuell projektering har implementerats i större utsträckning än visuell styrning, detta för att visuell projektering har ett mer utvecklat underlag. En jämförelse av verktygens implementering har gjorts.

  • 5.
    Andersson, Josefine
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Svensson, Simon
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Mätning av fuktkvot i sammansatta KL-träelement2018Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Moisture related damage is an occurring problem in wood-based buildings if the material is exposed to rainfall during construction. Measurement of moisture content can be done with various instruments and methods. The purpose of the thesis is to study change in moisture content in cross-laminated-timber, with prolonged exposure to water in laboratory environment. To advance the field, the Linnaeus University has been developing a measurement instrument of their own in collaboration with the company Saab. The instrument measures electrical resistance in wood where the obtained values will be compared to similar measurements from a product named Gigamodule. The self-developed sensor card is still a product under development. In addition to the lab setting measurements the instrument was also installed in a local building in Växjö.

    To verify the result from the previously mentioned resistance measurers additional instruments and methods have been utilized. Two separate models have been used to represent the detail of the connection between the wall element and the joist. Both models have been submerged under water for an equal amount of time. The experimental setting took place between the 19th of April to the 18th of May 2018. The measurements and calculations have been resulting in values that can be the subject of internal evaluation. Difference in result based on the direction of the grain have been observed in several measurement methods. The CLT-elements demonstrated good drying properties despite periodically high moisture content and the wood indicate a return towards initial levels of moisture.

  • 6.
    Andersson, Niklas
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Granskning av reklamationer och dess orsaker hos Sävsjö Trähus AB: Review of complaints and reasons for that at Sävsjö Trähus AB2007Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    House production is a process where high quality thinking is important in order to avoid customers complaints. The niche of Sävsjö Trähus AB (STAB) is to adapt each house as close as possible to the specific requirements of the costumer. This complicates the production process of the houses and also increases the risk of possible complaints. During 2006 STAB had complaints orresponding to approximately 3,1 millions SEK. The aim and the purpose of this study is to examine the complaints, the checkpoints and the different stages in the process of house building in order to counteract the origin of complaints and to give advise that can reduce the number of inspection remarks.

    One result of the study is a division of complaints in damages that are physically caused and problems that are caused by wrong decisions - caused of lack of communication between involved persons. In order to counteract the origin of complaints more intensive and clearer information should be exchanged among involved parties e.g. with the help of the business programme Pyramid. 3D blueprints should also be made in order to communicate what the house will look like when it is finished. This will make the customer aware of what has been decided in an early stage. Another recommendation is a change of the salesmen’s education in order to get a better overall vision of the house production (go beside a salesman, a draughtsman, production personnel and finally maybe

    also participate in a house rising). STAB should also continue to reward salesmen that achieve no remarks at the inspection. Further STAB should commit skilled installers or engage own assembly staff under STAB or under the salesman and demand that this staff makes all of the house risings. Further STAB should to subcontractors emphasize the need for improved packaging of woodwork.

  • 7.
    Baradaran, Sam
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Al-Wedd, Amir
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Arbetsberedningar på NCC: Undersökning om hur arbetsberedningar används som ett verktyg för att effektivisera produktionsprocessen2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I byggbranschen påverkar planering omkostnader och kvalité vilket gör att det krävs en bra och noggrant planering innan ett byggprojekt påbörjas. Arbetsberedningar är ett planeringsverktyg som används vid genomförandefasen med syfte att effektivisera arbetet. Denna studie beskriver hur arbetsberedningar på NCC Construction AB används och vad den har för påverkan samt hur den kan förbättras. I denna studie har fyra av NCCs arbetsplatser undersökts, där både ledning och medarbetare intervjuats. Studien visar att arbetsberedningar på många sätt är ett uppskattat planeringsverktyg av ledning och ett bra underlag för yrkesarbetarna samtidigt som flera anser sig klara sig utan dem. Arbetsledningen inser dock att det borde lägga större fokus på att göra regelbunden uppföljning av arbetsberedningarna.   

    De intervjuade anser att få förändringar behöver göras vad gäller arbetsberedningens utformning och användning. Dock har förbättringsförslag hittats och föreslagits.

  • 8.
    Berkowicz, Kasper
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Undersökning av byggprodukter och material för Svanenmärkt byggnad2016Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Svanen är Nordens officiella miljömärkningssystem, där många olika produkter kancertifieras. Detta arbete är en del av processen för byggföretaget GBJ Bygg att uppnåSvanenmärkning av ett av sina typhus. I arbetet utförs en energiberäkning på husetför att undersöka om huset klarar Svanens energikrav. Vidare undersöks en rad olikabyggprodukter och -material och jämförs mot Svanens krav. Syftet med arbetet är att skapa en lista med produkter och material som GBJ kan använda vid byggnation av ett Svanenmärkt hus, samt att ge förslag på eventuella ändringar som behöver göras för att huset ska klara Svanens energikrav. Energiberäkningen gjordes med hjälp av datorprogrammet VIP Energy, i samråd med en energisakkunnig ingenjör, medan undersökningen av produkterna främst gjordes via insamling av information från olika hemsidor och dokument hämtade fråninternet, samt kommunikation med tillverkarna. Resultaten visar att ändringar krävs för att huset skall uppfylla energikravet. Av 81 undersökta produkt anses 58 kunna godkännas för användning vid byggnation av en Svanenmärkt byggnad.

  • 9.
    Björksund, Johanna
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Berntsson, Moa
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Kopplingar mellan massiva prefabricerade plattor och ytterväggar2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    En av de mest kritiska momenten mellan prefabricerade betongelement är förankringen. Den är en viktig del för att t.ex. kunna undvika fortskridande ras. Abetong AB är ett av landets ledande betongföretag inom prefabricerade betongelement och de använder tre olika förankringsmetoder. Målet är att ta reda på kapaciteten för de olika förankringsmetoderna mellan prefabricerade betongelement. Syftet är att få fram underlag för att kunna förespråka eller avråda från olika förankringsmetoder. För att kunna förespråka eller avråda från de olika metoderna har hänsyn tagits till, kapaciteter vid dragprover, de beräknade konbrottskapaciteterna, kopplingstid, hur lång tid varje förankring tar att koppla till elementen, samt kostnad, styckpris och arbetskostnad.

  • 10.
    Bollvik, Mikael
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Svensson, Pontus
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Dagvattenhantering på Arenastaden i Växjö2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Rapporten behandlar projekteringen och genomförandet kring det lokala omhändertagandet av dagvatten för de fyra nybyggda arenorna på Arenastaden i Växjö. Granskningen behandlar framförallt underjordiska fördröjningsmagasin men även alternativa lösningar.

    Arbetet har genomförts med hjälp av intervjuer och studier kring olika lösningar för lokalt omhändertagande av dagvatten.

    Förändringsförslagen som presenteras bottnar i mer tid för projektering, förbättrad kommunikation och större användande av mer genomsläppliga ytor.

  • 11.
    Brandon, Daniel
    et al.
    RISE Research Institutes of Sweden.
    Schmid, Joachim
    ETH Zürich, Switzerland.
    Su, Joseph
    National Research Council of Canada.
    Hoehler, Matthew
    NIST National Institute of Standards and Technology, USA.
    Östman, Birgit
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Kimball, Amanda
    Fire Protection Research Foundation, USA.
    Experimental Fire-Simulator for Post-Flashover Compartment Fires2018In: SiF 2018 - The 10th International Conference on Structures in Fire, Belfast, UK, New University of Ulster, 2018Conference paper (Refereed)
    Abstract [en]

    The number of talltimber buildings around the world is rapidly increasing as a result of changes inregulations and the development of new engineered timber products. However, dueto the combustibility of timber, the fire safety of tall timber buildings hasbeen questioned. Building regulations for structural elements are based onfixed periods for which specimens shall resist exposure to a ‘standard fire’ ina fire resistance furnace. Because no distinction is made between the exposure in fire resistancetests of combustible and non-combustible specimens, less conventional testingmethods have been used for research of timber structures. Thisstudy aims to identify aspects that are important to simulate realistic fireconditions relevant to assess the structural performance of timber inpost-flashover fires. A test method is developed to replicate conditions incompartment fire tests using a furnace, that results in similar damage typesand rates of damage in the timber specimen. Based on conclusions drawn fromthese tests and test results obtained using other testing methods, theapplicability of fire resistance tests and other non-conventional tests arediscussed.

  • 12.
    Bravo, Giangiacomo
    et al.
    University of Turin, Italy ; Collegio Carlo Alberto, Italy.
    Tamburino, Lucia
    University of Padua, Italy.
    Are two resources really better than one?: Some unexpected results of the availability of substitutes2011In: Journal of Environmental Management, ISSN 0301-4797, E-ISSN 1095-8630, Vol. 92, no 11, p. 2865-2874Article in journal (Refereed)
    Abstract [en]

    The possibility of exploiting multiple resources is usually regarded as positive from both the economic and the environmental point of view. However, resource switching may also lead to unsustainable growth and, ultimately, to an equilibrium condition which is worse than the one that could have been achieved with a single resource. We developed a dynamic model where users exploit multiple resources and have different levels of preference among them. In this setting, exploiting multiple resources leads to worse outcomes in both economic and ecological terms than the single resource case under a wide range of parameter configurations. Our arguments are illustrated using two empirical situations, namely oil drilling in the North Sea and whale hunting in the Antarctic.

  • 13.
    Dahl, Arvid
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Lindström, Charlie
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Mekanisk prestanda hos traditionella träfogar kontra samtida byggbeslag2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Societies demand for environmentally friendly and sustainable construction is ever increasing. One way to meet these new demands on environmentally friendly construction is to use more wood which decreases carbon emissions through the substitution effect. This report aims to research whether traditional joinery techniques entirely executed in wood can replace contemporary joinery techniques in future construction. The goal is to show whether this is possible from a strength standpoint. The research will be limited in that it will strictly seek to study a pillar-beamconnection where the traditional joint researched will be three varying mortise and tenon joints and the contemporary joint is a joist hanger. The joints will be analyzed with calculation and experimentation where the load case aims to produce mainly shear in the joint. The results point towards it being possible to introduce this traditional joint in contemporary construction.

  • 14.
    Dalstrand, Joakim
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    van der Meer, Bas
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Orsaker till och möjligheter att minska spill av gipsskivor i byggprocessen2019Independent thesis Basic level (degree of Bachelor), 180 HE creditsStudent thesis
    Abstract [en]

    The construction industry is facing challenges when it comes to increased costs, defective timetables and inadequate material handling. The purpose of the study is to highlight and propose possible improvements to the process of using plasterboards in the construction industry. The aim of the survey is to investigate how the use of plasterboards can be made more efficient through better collaboration between stakeholders in the construction industry and to identify shortcomings in the current construction process. Interviews were used to produce improvements and shortcomings. The result showed that there is a lack of communication between actors and when handling plasterboards. Other shortcomings in the industry are documentation of changes made during production and cooperation between actors.

  • 15.
    Davidsson, Oscar
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Obrelius, Marcus
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Faktorer och aspekter att beakta vid solcellsinstallationer2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The global energy use must change, more than 80 % of the primary energy use is currently based on fossil fuels. To achieve a more sustainable development, a larger part of the energy consumption must be produced from renewable energy sources, such as solar energy.

    The purpose of this study is to exemplify practical, technical, economical and architectural factors and aspects that should be taken into consideration regarding solar cell integration in buildings. Through a case study, the Sankt Sigfrid area in Växjö was examined and bounded to four properties with possible solar cell installation as well as a possible solar cell park.

    Through theory, study visits, observations, solar study as well as technical and economical calculations, the solar cells' possible electricity production and potential savings were demonstrated. The integration proposals were compiled through the obtained theory and a survey based on how the design of building objects is affected by a solar cell installation.

    With today's generous government subsidies, there is a possibility of economic profitability regarding solar cell investments, which is reflected in the profit calculation of the result. The case study also demonstrates the complexity of solar cell installations as well as how various practical, technical, economical, architectural factors and aspects complicate the integrations onto buildings.

  • 16.
    Dodik, Josip
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Dodik, Mario
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    En jämförelse av 6 aktuella bostadsområden i Sverige med uttalad inriktning på hållbart stadsbyggande2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Under det senaste århundradet har det dykt upp många miljöproblem som har lett till att vi idag måste fokusera mer på en hållbar utveckling av våra städer.

    Allt fler människor väljer att bo i städer och därför är det viktigt för vår framtid att stadsplaneringen blir så hållbar som möjligt.

    Denna rapport beskriver och värderar 6 olika hållbara stadsdelar i Sverige. Dessa har identifierats och värderats utifrån 6 hållbarhetsaspekter som anses vara viktiga.

    Studierna har begränsats till hållbar utveckling inom stadsplanering, de pa- rametrar som tas upp i examensarbetet ”En jämförelse av 6 aktuella bo- stadsområden i Sverige med uttalad inriktning på hållbart stadsbyggande” är; Transport, Social Hållbarhet, Grönskande Utomhusmiljö, Hållbara Transporter, Hållbart Energisystem, Miljöanpassade Bostäder & Lokaler, Hållbart Vatten & Avlopp och Hållbar Återvinning. 

  • 17.
    Dodoo, Ambrose
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Primary energy and economic performances of cost-optimal retrofit measures for a district heated building2019In: Forum Wood Building Baltic 2019, 27 February- 1 March, Tallinn, Estonia., Tallin University of Technology , 2019Conference paper (Other academic)
  • 18.
    Dodoo, Ambrose
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Gustavsson, Leif
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Sathre, Roger
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Carbon implications of end-of-life management of building materials2009In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 53, no 5, p. 276-286Article in journal (Refereed)
    Abstract [en]

    In this study we investigate the effects of post-use material management on the life cycle carbon balance of buildings, and compare the carbon balance of a concrete-frame building to that of a wood-frame building. The demolished concrete is either landfilled, or is crushed into aggregate followed by exposure to air for periods ranging from 4 months to 30 years to increase carbonation uptake of CO2. The demolished wood is assumed to be used for energy to replace fossil fuels. We calculate the carbon flows associated with fossil fuel used for material production, calcination emission from cement manufacture, carbonation of concrete during and after its service life, substitution of fossil fuels by recovered wood residues, recycling of steel, and fossil fuel used for post-use material management. We find that carbonation of crushed concrete results in significant uptake of CO2. However, the CO2 emission from fossil fuel used to crush the concrete significantly reduces the carbon benefits obtained from the increased carbonation due to crushing. Stockpiling crushed concrete for a longer time will increase the carbonation uptake, but may not be practical due to space constraints. Overall, the effect of carbonation of post-use concrete is small. The post-use energy recovery of wood and the recycling of reinforcing steel both give higher carbon benefit than the post-use carbonation. We conclude that carbonation of concrete in the post-use phase does not affect the validity of earlier studies reporting that wood-frame buildings have substantially lower carbon emission than concrete-frame buildings.

  • 19.
    Dodoo, Ambrose
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Gustavsson, Leif
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Sathre, Roger
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Energy implications of end-of-life options for building materials2008In: First International Conference on Building Energy and Environment, Proceedings Vols 1-3, Dalian, China: Dalian University Technology Press , 2008, p. 2025-2032Conference paper (Refereed)
    Abstract [en]

    The energy flows associated with the materials comprising a building can be a significant part of the total energy used in a building's life cycle. Buildings have finite life spans, and the materials from demolished buildings can be either a burden that must be disposed, or a resource that can be used. In this paper we analyse the end-of-life energy impacts of concrete, steel and wood. End-of-life options considered include reuse; recycling; downcycling; energy recovery; and disposal in landfill. We follow the life cycles of the building materials from the acquisition of natural resources through to the end of the product's life cycle. We identify possibilities and constraints for integrating more effective end-of-life material processing options into existing industrial systems.

  • 20.
    Dodoo, Ambrose
    et al.
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Gustavsson, Leif
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Sathre, Roger
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Life cycle primary energy implication of retrofitting a wood-framed apartment building to passive house standard2010In: Resources, Conservation and Recycling, ISSN 0921-3449, E-ISSN 1879-0658, Vol. 54, no 12, p. 1152-1160Article in journal (Refereed)
    Abstract [en]

    Here we analyze the life cycle primary energy implication of retrofitting a four-storey wood-frame apartment building to the energy use of a passive house. The initial building has an annual final energy use of 110 kWh/m(2) for space and tap water heating. We model improved thermal envelope insulation, ventilation heat recovery, and efficient hot water taps. We follow the building life cycle to analyze the primary energy reduction achieved by the retrofitting, considering different energy supply systems. Significantly greater life cycle primary energy reduction is achieved when an electric resistance heated building is retrofitted than when a district heated building is retrofitted. The primary energy use for material production increases when the operating energy is reduced but this increase is more than offset by greater primary energy reduction during the operation phase of the building, resulting in significant life cycle primary energy savings. Still, the type of heat supply system has greater impact on primary energy use than the final heat reduction measures.

  • 21.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Sathre, Roger
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Lifecycle carbon implications of conventional and low-energy multi-storey timber building systems2014In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 82, p. 194-210Article in journal (Refereed)
    Abstract [en]

    A consequential-based lifecycle approach is used here to explore the carbon implications of conventional and low-energy versions of three timber multi-storey building systems. The building systems are made of massive wood using cross laminated timber (CLT) elements; beam-and-column using glulam and laminated veneer lumber (LVL) elements; and prefabricated modules using light-frame volume elements. The analysis encompasses the entire resource chains during the lifecycle of the buildings, and tracks the flows of carbon from fossil energy, industrial process reactions, changes in carbon stocks in materials, and potential avoided fossil emissions from substitution of fossil energy by woody residues. The results show that the low-energy version of the CLT building gives the lowest lifecycle carbon emission while the conventional version of the beam-and-column building gives the highest lifecycle emission. Compared to the conventional designs, the low-energy designs reduce the total carbon emissions (excluding from tap water heating and household and facility electricity) by 9%, 8% and 9% for the CLT, beam-and-column and modular systems, respectively, for a 50-year lifespan located in Växjö. The relative significance of the construction materials to the fossil carbon emission varies for the different energy-efficiency levels of the buildings, with insulation dominating for the low-energy houses and plasterboard dominating for the conventional houses.

  • 22.
    Dodoo, Ambrose
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Tettey, Uniben Yao Ayikoe
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Gustavsson, Leif
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Impacts of Common Simulation Assumptions in Sweden on Modelled Energy Balance of a Multi-family Building.2019In: Cold Climate HVAC 2018 / [ed] Johansson D., Bagge H., Wahlström Å., Springer, 2019, p. 689-699Conference paper (Refereed)
    Abstract [en]

    Here, we explore key input parameters and common assumptions for energy balance analysis of residential buildings in Sweden and assess their impacts on simulated energy demand of a building. Our analysis is based on dynamic hour-by-hour energy balance modelling of a typical Swedish multi-storey residential building constructed in 1972. The simulation input parameters studied are related to microclimate, building envelope, occupancy behaviour, ventilation, electric and persons heat gains. The results show that assumed indoor temperature set points, internal heat gains and efficiency of ventilation heat recovery systems have significant impact on the simulated energy demand. For microclimate parameters, the outdoor temperature, ground solar reflection and window shading gave significant variations in the simulated space heating and cooling demands. We found that input parameter values and assumptions used for building energy simulation vary significantly in the Swedish context, giving considerably different estimated annual final energy demands for the analysed building. Overall, the estimated annual final space heating demand of the building varied between 50 and 125 kWh/m2 depending on the simulation dataset used. This study suggests that site-specific parameter values may be appropriate for accurate analysis of a building’s energy performance to reduce data input uncertainties, as such factors may have a significant impact on building energy balance and energy savings of retrofit measures.

  • 23.
    Dorn, Michael
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Kozłowski, Marcin
    Silesian University of Technology, Poland.
    Serrano, Erik
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Development of large-scale load-bearing timber-glass structural elements2014In: WCTE 2014 - World Conference on Timber Engineering: Proceedings, 2014Conference paper (Refereed)
    Abstract [en]

    The building industry demands ever more effective structural elements with a multitude of requirements at the same time. There is increasing interest for load-bearing glass elements which can be deployed in timber structures, e.g. in the outer façade or as column or beam elements within the building. In an on-going research project, the materials glass, timber and the adhesive combining the former have to be selected to fit each other but also suit the application. The mechanical properties are studied individually as well as in combined small-scale specimens experimentally. Furthermore,large-scale tests on beams and shear walls are performed. This is accompanied by numerical analysis to study a wide range of dimensions and variations as well as specific design situations. The final output of the project will be prototypes to beused in showcase projects.

  • 24.
    Edvardsson, Andreas
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Eriksson, Anders
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Hallbyggnadsteknik - en effektivisering av småhusproduktion2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim with this diploma work is to see if it is possible to transfer the technology used for industrial buildings to the production of small houses to lower the production costs. In the report, we show that the industrial building technology is possible to transfer to a small house. It also becomes more efficient to build the climate shell with our construction system compared with a traditional prefabricated small house. The total construction cost can with our system be reduced with 3-10 % depending on which facade material that is chosen.

  • 25.
    Elwing, Charlotta
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Sjögren, Kristin
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Prefabricerade hus - en fråga om kvalitet, ekonomi och byggtid2006Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The main purpose with this diplomawork is to compare the two production methods,

    premanufacturing and on-site construction. We want to investigate if one of the methods is more advantageous than the other and why premanufactured elements are used more often. The comparisons mostly consider aspects of building time, economy and quality. We gathered the material we needed through a literature study and by interviewing active persons in the building industry.

    Building as much as possible in a production hall increases the quality since it’s not being exposed to moisture and cold before assembly. The house is built much faster when the building site becomes a montage place with different finished elements. There is no material storage at the building site since the elements are delivered when it’s time to assemble the specific element. If the elements are delivered when needed, building time will decrease which means reduced costs for the whole project.

  • 26.
    Falkstål, Linus
    Linnaeus University, Faculty of Technology, Department of Mathematics.
    Entreprenöriellt lärande som verktyg i en föränderlig värld: En studie om värdeskapande lärande, entreprenöriella förmågor och dess inverkningar på problemlösning i matematik.2018Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Studien är en pedagogisk designforskning som genom en intervention belyser hur de entreprenöriella förmågorna komplexitet, ansvar och samverkan framträder genom en kombination av metoderna värdeskapande lärande och matematisk modellering. Studien avser också att belysa om metoderna kan bidra till ett kontextuellt och strategiskt matematiskt kunnande. Resultatet består av en beskrivning och analys av de förmågor som framträtt samt en analys av de designprinciper som användes för att tillverka den uppgift som eleverna använde under projektets gång. Resultatet visar att kombinationen av metoderna värdeskapande lärande och matematisk modellering, dels genom sin verklighetsanknytning och uppmuntrande till elevers engagemang, skapar goda möjligheter för ovanstående förmågors framträdande. Den andra delen av resultatet visar att eleverna behöver ges en god förförståelse för att bibehålla ett matematiskt fokus igenom hela uppgiftsprocessen.

  • 27.
    Forss, Jörgen
    Linnaeus University, Faculty of Technology, Department of Built Environment and Energy Technology.
    Continuous system based on rice husks for biodegradation of a simulated textile waste water containing azo dyes2013In: Continuous system based on rice husks for biodegradation of a simulated textile waste water containing azo dyes, International Water Association, Elsevier, 2013Conference paper (Other academic)
  • 28.
    Fransson, Mattias
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Jamtlien, Mattias
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Slöseri i produktionsflödet: Analys av en platsgjuten betongvägg2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    High construction costs and considerable housing shortages in Sweden show that a more efficient housing construction is required. A reduction of waste in the construction process contributes to the efficiency of both time and cost. In order to increase the understanding of the importance of efficiency, this study reveals waste in the production flow of a cast in-situ concrete wall in a housing project. The study also shows where in the production flow there are improvement opportunities.

    The waste was made visible through a time study which showed great potential for improvement in the housing project resource flow, material flow and information flow. There are many indications that these shortcomings in the production flow are due to a too short construction time, which means that a good planning is not always carried out.

  • 29.
    Fält, Pernilla
    Växjö University, Faculty of Mathematics/Science/Technology, School of Technology and Design.
    Från 2D till BIM i ett trähusföretag: Transition from 2D-CAD to BIM in a timber frame home company2009Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    A prefabricated timber frame house previously built by Villafabriken AB has been modeled in Autodesk Revit Architectural, a 3D-program based on BIM-technology. This has been done tosee if it’s possible to produce the publications that Villafabriken demands from the designengineer’s work, and examine which possible extra values that may arise compared to traditional 2D-CAD drawing.BIM is short for Building Information Modeling. Everything is stored in a single database and a change in the project file is automatically updated across the project. BIM provides more than just drawings since information from the model can be retrieved in various ways such as lists and quantity schedules.It was possible to produce the publications that Villafabriken demanded using Revit, but BIM doesn’t only mean a new way of drawing, it also require a change in the company’s process were the information from the model is being used.

  • 30.
    Gottfridsson, Simon
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Eriksson, David
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Riskreduceringsmetod för entreprenörer vid anbudslämnande2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Examenarbetet handlar om hur entreprenörer med hjälp av en checklista ska kunna identifiera, analysera och minimera risker som uppstår när ett förfrågningsunderlag börjar studeras till att ett eventuellt anbud lämnas. Syftet med examensarbetet är att entreprenörerna ska känna sig säkra när de lämnar anbud på ett förfrågningsunderlag. För att uppnå målet har tre stycken intervjuer genomförts och fem förfrågningsunderlag samt litteratur studerats. Resultatet av examensarbetet presenteras i form av en checklista som entreprenörerna kan använda sig av för att medvetandegöra risker vid anbudslämning och att entreprenören ska kunna använda den för att öka chansen att vinna anbudet.

  • 31.
    Gren Bernhäll, Oscar
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Nilsson, Adam
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Bestämning av mekaniskaegenskaper för ett bio-kompositmaterial2017Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the work is the determination of flexural properties for thebiocomposite Durapulp. The study includes laborative tests on Durapulp andreference materials, commonly used in the building sector. Stiffness and strength of Durapulp show that it has the potential as a replacement for conventional wood-based materials.

  • 32.
    Grennborg, Frida
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Larsson, Sofia
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Granskning av tidplaner: hur kan arbetet bli effektivare?2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Tidsplanering är en viktig del i styrningen av byggprojekt. Olika typer av tidplaner kan användas i projekt, beroende på storlek och vilken fas det befinner sig i. Studien granskar tidplanerna från tre tidigare flerbostadshusprojekt som Skanska har byggt. Utifrån detta analyseras och jämförs planerna med hur projekten lyckats med avseende på tidshållning. Syftet med studien är att ge Skanska möjlighet att utveckla tidplaneringsarbetet.

    Studien avslutas med rekommendationer kring viktiga byggstenar i tidplanerna och vilka planer som är viktiga att använda. Analysen omfattar även användandet av programmet ”Asta Powerproject” som används för upprättande av tidplanerna. 

  • 33.
    Gustafsson, Fredrik
    et al.
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering. Industriell Ekonomi.
    Söderström, Henrik
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering. Industriell Ekonomi.
    Industriellt synsätt på värdeflödet vid anläggningsarbeten genom visuell styrning2016Independent thesis Basic level (professional degree), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [sv]

    Syftet med studien är att studera vilka möjligheter arbetsledningen på svenska byggföretag har, att på ett effektivare sätt styra värdeflödet av resurser med visuell styrning. Målet med studien är att identifiera förbättringsförslag och fördelar som finns och som kan skapas med visuell styrning för arbetsledningen vid anläggningsarbeten.Studien bygger på mätningar som har genomförts på ett anläggningsarbete av en cirkulationsplats i Ullared under 7 dagar där Skanska AB var entreprenör.Under mätningarna har författarna tagit fram fördelar och förbättringsförslag som finns eller kan skapas med visuell styrning. Slutsats och diskussion ska ge en indikation till svenska byggföretag om vad de kan göra för att tillgodogöra sig framstegen från tillverkningsindustrin.

  • 34.
    Gustafsson, Åsa
    et al.
    Linnaeus University, Faculty of Business, Economics and Design, Linnaeus School of Business and Economics.
    Vessby, Johan
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Rask, Lars-Olof
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Identification of potential improvement areas in industrial housing: A case study of waste2012In: Lean Construction Journal, ISSN 1555-1369, E-ISSN 1555-1369, p. 61-77Article in journal (Refereed)
  • 35.
    Gustavsson, Leif
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering. Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Dodoo, Ambrose
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Truong, Nguyen Le
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Danielski, Itai
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Primary energy implications of end-use energy efficiency measures in district heated buildings2011In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 43, no 1, p. 38-48Article in journal (Refereed)
    Abstract [en]

    In this study we explore the effects of end-use energy efficiency measures on different district heat production systems with combined heat and power (CHP) plants for base load production and heat-only boilers for peak and medium load productions. We model four minimum cost district heat production systems based on four environmental taxation scenarios, plus a reference district heat system used in Östersund, Sweden. We analyze the primary energy use and the cost of district heat production for each system. We then analyze the primary energy implications of end-use energy efficiency measures applied to a case-study apartment building, taking into account the reduced district heat demand, reduced cogenerated electricity and increased electricity use due to ventilation heat recovery. We find that district heat production cost in optimally-designed production systems is not sensitive to environmental taxation. The primary energy savings of end-use energy efficiency measures depend on the characteristics of the district heat production system and the type of end-use energy efficiency measures. Energy efficiency measures that reduce more of peak load than base load production give higher primary energy savings, because the primary energy efficiency is higher for CHP plants than for boilers. This study shows the importance of analyzing both the demand and supply sides as well as their interaction in order to minimize the primary energy use of district heated buildings.

  • 36.
    Gustavsson, Leif
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Engineering. Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Truong, Nguyen Le
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Dodoo, Ambrose
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Sathre, Roger
    Mittuniversitetet, Institutionen för teknik och hållbar utveckling.
    Effects of environmental taxations on district heat production structures2011In: World Renewable Energy Congress 2011, Linköping, Sweden, May 8-11 / [ed] Bahram Moshfegh, Linköping University Electronic Press, 2011, p. 3420-3427Conference paper (Refereed)
  • 37.
    Haavik, Trond
    et al.
    Segel As, Norway.
    Aabrekk, Synnøve
    Segel As, Norway.
    Svendsen, Svend
    Danish Technical University, Lyngby, Denmark.
    Tommerup, Henrik
    Technical University of Denmark.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Gustavsson, Leif
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Paiho, Satu
    VTT, Espoo, Finland.
    Ala-Juusela, Mia
    VTT, Espoo, Finland.
    Report on stakeholders interests, Deliverable D2.2 of the project Successful Sustainable Renovation Business for Single-Family Houses - SuccessFamilies.2011Report (Other academic)
  • 38.
    Haavik, Trond
    et al.
    Segel As, Norway.
    Tommerup, Henrik
    Technical University of Denmark.
    Svendsen, Svend
    Danish Technical University, Lyngby, Denmark.
    Paiho, Satu
    VTT, Espoo, Finland.
    Ala-Juusela, Mia
    VTT, Espoo, Finland.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Gustavsson, Leif
    Mid Sweden University.
    Aabrekk, Synnøve
    Segel As, Norway.
    Næsje, Peik
    Mlecnik, E.
    Cré, Johan
    Vrijders, Jeroen
    New business models for holistic renovation solutions of single family houses2011Conference paper (Refereed)
    Abstract [en]

    Single family houses represent the biggest potential for energy savings within residential buildingsin the Nordic countries. In earlier research project [1] it highlighted that there is a missing linkbetween the single family house owner and various segregated offers of single solutions forrenovation and/or energy efficiency installations. In the two international research projectsSuccessFamiles and One Stop Shop, establishment of new business models as pilots for bridgingthis gap are now being monitored.Two of the pilots as “one stop shops”, a retailer chain in Finland and a daughter company of aNorwegian manufacturer of insulation, are described and discussed.A key issue for any business model which offers an integrated service from analysis of the houseand recommendations for measures is the trustworthiness of the supplier.As a holistic energy efficient renovation project is a “new” and unknown service to single familyhouse owner and at same time a costly investment, it is important for the suppliers to findadequate ways of communicating through each phase of the buying process. There are variouschallenges in each of the phases which have to be solved differently.

  • 39.
    Hansen, Fredrik
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Palmquist, Jesper
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Från CAD till BIM inom småhusindustrin2015Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    BIM står för Building Information Modeling. Det är en ny teknik för att konstruera en virtuell modell av en byggnad i digitalt format. De stora fördelarna med BIM är att alla komponenter som läggs till i modellen innehåller information. Av informationen genereras automatiskt de handlingar och listor som behövs. Dessutom fås presentationsmaterial i form av 3D-modeller utan något extra arbete. Undersökningen behandlar ett företag och varför de inte genomfört en övergång från 2D-CAD till BIM och syftet är därför att visa dem vilka effektiviseringsmöjligheter som finns. 

  • 40.
    Harrysson, Jacob
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Strandman, Johanna
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Ökad återvinning med en ny design av miljöhus2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This work shows a design proposal of a modern recycling house, which is developed to ease waste sorting in a community, based on architectural och technical functions. The work is based on the constantly growing environmental issues that affects planet earth. Waste sorting och recycling are two important factors that have to be further developed to contribute to a reduced climate change.

    The study is based on previous produced theories, observations, surveys and interviews with experts in different areas. The results shows that a recycling house with no front or back and without entrance, makes it easier for people to engage in waste sorting.

  • 41.
    Hemström, Kerstin
    et al.
    Mid Sweden University.
    Mahapatra, Krushna
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Gustavsson, Leif
    Linnaeus University, Faculty of Science and Engineering, School of Engineering.
    Swedish architects’ perceptions of hindrances to the adoption of wood frames and other innovations in multi-storey building construction2011In: SB11 Helsinki World Sustainable Building Conference, 2011Conference paper (Refereed)
    Abstract [en]

    A better understanding of general hindrances to the diffusion of innovations (new products,services, processes, systems, or concepts) in the construction sector may help improve thesustainability of buildings. Adoption of innovations such as multi-storey wood frames may e.g.reduce the primary energy use and carbon dioxide emissions of building construction. This studyuses a web-based questionnaire to collect information on Swedish architects‟ perceptions ofhindrances to the adoption of innovations in building construction in general, and to the adoption ofmulti-storey wood frames in particular. Results show that the most influential hindrances to thegeneral adoption of innovations were perceived as the focus on project costs instead of life-cyclecosts, the economic risk adopting an innovation imply, the focus on traditional engineering models,the construction industry´s tendency to use proven materials and methods, and contractors‟inability to adjust processes. Concrete and steel were perceived as more advantageous than woodwith regards to several aspects influencing the innovativeness of the Swedish construction industry,but wood was perceived as better with regards to opportunities to support local industry. Thearchitects also had more positive perceptions of the performance of concrete and steel in multistoreybuildings, than of wood. While gender and size of company seem to have little influence,perceptions of innovativeness and frame materials vary with age and regions.

  • 42.
    Hoehler, Matthew
    et al.
    NIST National Institute of Standards and Technology, USA.
    Su, Joseph
    National Research Council of Canada.
    Lafrance, Pier-Simon
    National Research Council of Canada, Canada.
    Bundy, Matthew
    NIST National Institute of Standards and Technology, USA.
    Kimball, Amanda
    Fire Protection Research Foundation, USA.
    Brandon, Daniel
    RISE Research Institutes of Sweden.
    Östman, Birgit
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Fire Safety Challenges of Tall Wood Buildings: Large-scale Cross-laminated Timber Compartment Fire Tests2018In: SiF 2018– The 10th International Conference on Structures in FireFireSERT, Ulster University, Belfast, UK, June 6-8, 2018, New University of Ulster, 2018Conference paper (Refereed)
    Abstract [en]

    This study investigates the contribution of cross laminated timber (CLT) building elements to compartment fires. Six compartments (9.1 m long × 4.6 m wide × 2.7 m high) were constructed using 175 mm thick 5‑ply CLT structural panels and fire tested using residential contents and furnishings to provide a fuel load density of 550 MJ/m2. The results show that gypsum board can delay or prevent the involvement of the CLT in the fire, and that the ventilation conditions and exposed surface area of the CLT play a decisive role in the outcome of the test. The results highlight the need to use heat-resistant adhesives in cross laminated timber to minimize delamination.

  • 43. Hosokawa, Yoshifumi
    et al.
    Yamada, Kazuo
    Johannesson, Björn
    Technical University of Denmark, Denmark.
    Nilsson, L. O.
    A development of multi-Species mass transport model considering thermodynamic phase equilibrium2008In: International RILEM Symposium on Concrete Modelling - ConMod '08 / [ed] E. Schlangen and G. De Schutter, Rilem publications, 2008, p. 543-550Conference paper (Other academic)
    Abstract [en]

    In this paper, a multi-species mass transport model, which can predict time dependent variation of pore solution and solid-phase composition due to the mass transport into the hardened cement paste, has been developed. Since most of the multi-species models established previously, based on the Poisson-Nernst-Planck theory, did not involve the modeling of chemical process, it has been coupled to thermodynamic equilibrium model in this study. By the coupling of thermodynamic equilibrium model, the multi-species model could simulate many different behaviours in hardened cement paste such as: (i) variation in solid-phase composition when using different types of cement, (ii) physicochemical evaluation of steel corrosion initiation behaviour by calculating the molar ratio of chloride ion to hydroxide ion [Cl]/[OH] in pore solution, (iii) complicated changes of solid-phase composition caused by the penetration of mineral salts during marine seawater exposure conditions. Those phenomena in concrete can be predicted using the coupled multi-species mass transport model and the thermodynamic equilibrium model described in this paper.

  • 44.
    Hosokawa, Yoshifumi
    et al.
    Taiheiyo Cement Corporation, Japan.
    Yamada, Kazuo
    Taiheiyo Cement Corporation, Japan ; Taiheiyo Consultant Co, Japan.
    Johannesson, Björn
    Technical University of Denmark, Denmark.
    Nilsson, Lars-Olof
    University of Lund.
    Development of a multi-species mass transport model for concrete with account to thermodynamic phase equilibriums2011In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 44, no 9, p. 1577-1592Article in journal (Refereed)
    Abstract [en]

    In this study, a coupled multi-species transport and chemical equilibrium model has been established. The model is capable of predicting time dependent variation of pore solution and solid-phase composition in concrete. Multi-species transport approaches, based on the Poisson–Nernst–Planck (PNP) theory alone, not involving chemical processes, have no real practical interest since the chemical action is very dominant for cement based materials. Coupled mass transport and chemical equilibrium models can be used to calculate the variation in pore solution and solid-phase composition when using different types of cements. For example, the physicochemical evaluation of steel corrosion initiation can be studied by calculating the molar ratio of chloride ion to hydroxide ion in the pore solution. The model can, further, for example, calculate changes of solid-phase composition caused by the penetration of seawater into the concrete cover. The mass transport part of the model is solved using a non-linear finite element approach adopting a modified Newton–Raphson technique for minimizing the residual error at each time step of the calculation. The chemical equilibrium part of the problem is solved by using the PHREEQC program. The coupling between the transport part and chemical part of the problem is tackled by using a sequential operator splitting technique and the calculation results are verified by comparing the elemental spacial distribution in concrete measured by the electron probe microanalysis (EPMA).

  • 45.
    Hosseini, Payam
    et al.
    Sharif University of Technology, Iran ; Alaodoleh Semnani Institute of Higher Education, Iran.
    Hosseinpourpia, Reza
    Georg-August University, Germany.
    Pajum, Arash
    University of Tehran, Iran.
    Khodavirdi, Mohammad Mahdi
    University of Tehran, Iran.
    Izadi, Hamed
    Sharif University of Technology, Iran.
    Vaezi, Ali
    Politecnico di Milano, Italy.
    Effect of nano-particles and aminosilane interaction on the performances of cement-based composites: An experimental study2014In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 66, p. 113-124Article in journal (Refereed)
    Abstract [en]

    The aim of the present study was to experimentally investigate the interaction between a low replacement ratio of different nano-particles (SiO2, Al2O3, clay, and CaCO3) and aminosilane in the matrices of cement paste and mortar. Results showed that the optimum content of aminosilane for improving the 28-day compressive strength of cement mortar was 0.75% (by weight of the total binder). The utilization of nano-SiO2 and nano-clay particles improved the strengths of the cement mortar containing hybrid systems of nano-particles/aminosilane at early (7 days) and middle curing ages (28 and 91 days). The 28-day compressive strength enhancement of cement mortar with hybrid systems of nano-SiO2/aminosilane and nano-clay/aminosilane was about 19% and 20%, respectively. Additionally, the application of aminosilane with nano-CaCO3 and nano-Al2O3 particles showed lower efficacy on mechanical performance of the cement-based composites in comparison with nano-clay and nano-SiO2. Despite the fact that the utilization of aminosilane with and without different nano-particles enhanced the flowability of the cement paste and mortar, it reduced the electrical resistivity of the cement mortar. In this regard, the minimum electrical resistivity was achieved for specimens with only aminosilane. This reduction was about 19.5% for samples containing 0.75% aminosilane for a curing time of 28 days.

  • 46.
    Hosseinpourpia, Reza
    et al.
    Islamic Azad University, Iran ; Georg-August University, Germany.
    Hosseini, Payam
    Sharif University of Technology, Iran.
    Mofidian, Seyedehrashin
    Mazandaran University of Science and Technology, Iran.
    Hosseinpourpia, Rezvan
    Islamic Azad University, Iran.
    Varshoee, Ali
    Islamic Azad University, Iran.
    Influence of Nanosilica on Properties of Green Cementitious Composites Filled with Waste Sulfite Pulp Fiber and Aminosilane2014In: The Arabian Journal for Science and Engineering, ISSN 1319-8025, Vol. 39, no 4, p. 2631-2640Article in journal (Refereed)
    Abstract [en]

    Developments in the field of green cement-based products are characterized as an important approach to sustainable development and are being devoted much attention by the construction industry. Numerous types of materials are utilized; however, based on other published studies, the use of waste material as a filler normally deteriorates the performance of cementitious products. Appropriate additives thus need to be employed to improve the performances and properties of green products. As a consequence, the aim of this study has been to investigate the properties of a novel green cement-based composite—a hybrid system composed of cement, waste natural fiber, silica nano-particles, and aminosilane. Experiments were performed to assess the physical properties (density and flowability), mechanical properties (compressive strength and bending performance), and microstructural properties (as determined by scanning electron microscopy) of the cement sheets. The results demonstrated an improvement in the mechanical and microstructural properties of green cement-based composites by using this hybrid system.

  • 47.
    Hosseinpourpia, Reza
    et al.
    Islamic Azad University, Iran.
    Varshoee, Ali
    Islamic Azad University, Iran.
    Soltani, Mojtaba
    Islamic Azad University, Iran.
    Hosseini, Payam
    Sharif University of Technology, Iran.
    Effects of sulfite waste fibers incorporating silica nano-particles on mechanical and microstructural properties of cementitious composite2010In: 2nd International Conference on Composites: Characterization, Fabrication and Application, 2010, p. 431-436Conference paper (Refereed)
    Abstract [en]

    Natural fibers are one of the most appropriate alternatives for designation and production of structural panels due to low final production cost. However a principal point is the strength loss caused by usage of these fibers in the matrix of cement based composites. Hence, a simple and cheap method should be applied to develop the properties of these fibers. Therefore, in this study by application of sulfite waste (along with waste management in the wood and paper industries) and usage of low-dosage silica nanoparticles (in order to enhance the interfacial transition zone of the cement-fiber paste), production of cement based sheets reinforced with natural fibers and silica nano-particles are investigated. Alongside, flexural strength and microstructure of sheets are examined by calculating the Modulus of Rupture (MOR) and Modulus of Elasticity (MOE), and applying the Scanning Electron Microscopy (SEM), respectively. Results show that mechanical performance and microstructure of cement based composites containing waste natural fibers and silica nano-particles can be improved.

  • 48.
    Hosseinpourpia, Reza
    et al.
    Islamic Azad University, Iran ; Georg-August University, Germany.
    Varshoee, Ali
    Islamic Azad University, Iran.
    Soltani, Mojtaba
    Islamic Azad University, Iran.
    Hosseini, Payam
    Sharif University of Technology, Iran.
    Ziaei Tabari, Hassan
    Islamic Azad University, Iran.
    Production of waste bio-fiber cement-based composites reinforced with nano-SiO2 particles as a substitute for asbestos cement composites2012In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 31, p. 105-111Article in journal (Refereed)
    Abstract [en]

    The environmental impact of asbestos fibers on human health and their consequent safety-related problems indicate that there is a significant need to replace this material in all asbestos-containing products. Many different types of fibers have been introduced to replace asbestos fibers.

    In this study, the performance of silica nano-particles combined with waste paper pulp fibers (sulfite fibers) has been investigated. Different mechanical (compressive and flexural strengths and bending performance), durability (water absorption), physical (bulk density and flowability), and microstructural (scanning electron microscopy) tests were conducted to examine the properties of manufactured green composites.

    The results reveal that the mechanical properties of cement-based composites containing a ternary system of “natural waste fiber–silica nano-particle cement” have been enhanced. Adding silica nano-particles allows the development of green cement-based composites and movement toward sustainable development in the concrete industry.

  • 49.
    Hu, Min
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Local variation in bending stiffness in structural timber of Norway spruce: for the purpose of strength grading2014Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Most strength grading machines on the European market use an averagemodulus of elasticity (MOE), estimated on a relatively large distance along awood member, as the indicating property (IP) to bending strength. Theaccuracy of such grading machines in terms of coefficient of determination israther low at R2 ≈ 0.5. This research is motivated by a desire to increase theaccuracy of the strength grading in the industry today. The aim of the presentstudy is to contribute knowledge of local variation in bending stiffness/MOEwith high resolution and thus locate weak sections due to stiffness reducingfeatures (the most important is knots) for structural timber.The present study introduces three methods that involve structural dynamics,classical beam theory and optical measurement to assess local wood stiffness.Specifically:

    • The dynamic method, in which a wood member is treated as an ordinaryphysical structure and the local stiffness is studied by exploring itsdynamic properties.
    • In Method II, a bending MOE profile is established based on local fibre angle information. The local fibre orientation is detected through highresolution laser scanning based on the tracheid effect.
    •  For Method III, a bending MOE profile is established using surfacestrain information under four-point bending. A high resolution strainfield is obtained using the digital image correlation (DIC) technique.

    From the present study, the two latter methods are more favourable inevaluating the local stiffness within a piece of structural timber. Moreover, thestudy reveals that the established bending MOE profiles using the two lattermethods, i.e. based on information of the local fibre angle and surface strain,agree reasonably well. However, for some patterns of knot clusters, the localbending MOE, calculated on the basis of fibre angles, is significantly higherthan the local bending MOE estimated on the basis of surface strain.

  • 50.
    Hu, Min
    et al.
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Johansson, Marie
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Olsson, Anders
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Oscarsson, Jan
    SP Tech Res Inst Sweden, SP Wood Technol, Växjö.
    Enquist, Bertil
    Linnaeus University, Faculty of Technology, Department of Building Technology.
    Local variation of modulus of elasticity in timber determined on the basis of non-contact deformation  measurement and scanned fibre orientation2015In: European Journal of Wood and Wood Products, ISSN 0018-3768, E-ISSN 1436-736X, Vol. 73, no 1, p. 17-27Article in journal (Refereed)
    Abstract [en]

    During the last decade, the utilization of non-contact deformation measurement systems based on digital image correlation (DIC) has increased in wood related research. By measuring deformations with DIC systems, surface strain fields can be calculated. The first aim of this study concerns the possibility to detect detailed strain fields along the entire length of a wooden board subjected to pure bending and the potential of using such strain fields to determine a bending modulus of elasticity (MOE) profile along a board. Displacements were measured over 12 subareas along a flat surface of the board. For each such area, a separate local coordinate system was defined. After the transformation of locally measured coordinates to a global system, high resolution strain fields and a corresponding bending MOE profile were calculated. A second method in establishing bending MOE profiles is to use fibre angle information obtained from laser scanning and a calculation model based on integration of bending stiffness over board cross sections. Such profiles have recently been utilized for accurate strength grading. A second aim of this study was to investigate the accuracy of the bending MOE profiles determined using the latter method involving fibre angle information. Bending MOE profiles determined using the two described methods agree rather well. However, for some patterns of knot clusters, the local bending MOE, calculated on the basis of fibre angles and integration of bending stiffness, is overestimated. Hence, this research adds knowledge that may be utilized to improve the newly suggested strength grading method.

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