Este trabalho tem por finalidade, o estudo do comportamento do adesivo poliuretano à base de mamona para o emprego em madeira laminada colada (MLC). A eficiência do adesivo foi avaliada por meio da resistência dos seguintes ensaios mecânicos: cisalhamento, tração normal e tração paralela às fibras. Os ensaios seguiram as recomendações da norma brasileira NBR 7190/97 \"Projeto de estruturas de madeiras\" e por meio de seus resultados foram determinados os parâmetros de colagem como: viscosidade (V), tempo de pressão de colagem (Tp), pressão de colagem (P) e tempo de cura (Tc) e avaliadas as influências dessas variáveis e de suas interações sobre as resistências. Duas espécies de madeira foram empregadas: o Pinus caribea hondurensis e o Eucaliptus grandis, geralmente empregadas em reflorestamento nas regiões Sul e Sudeste do Brasil, onde estão localizadas as indústrias de MLC. O adesivo estudado é do tipo bicomponente, o poliol B1640 e o prepolímero A249, oriundo de recurso natural e renovável, de cura a frio, não agressivo ao ser humano e nem ao meio ambiente e é uma tecnologia nacional. Os resultados mostraram que o adesivo à base de mamona é um boa alternativa para a utilização da madeira laminada colada em estruturas com espécies de reflorestamento. / The aim of this work is the study of the polyurethane adhesive based on castor oil in glued laminated timber structures (GLULAM). The efficiency of the adhesive was evaluated using the following mechanical tests: shear, perpendicular and parallel tension to the grain strengths. The Brazilian Code NBR 7190/97 \'\'Design of the timber structures\" was used to the tests and based on these results were determined the gluing parameters as: viscosity (V), gluing pressure (P), time of pressure (Tp) and the curing time (Tc) and evaluated the influence of these variables and interactions on the mechanical strengths. Two wood species Pinus caribea hondurensis and Eucaliptus grandis were chosen because they are used as reforestation in South and Southeast areas in Brazil where are located the glulam industries. The adhesive studied is of the two components, that is, the poliol B1640 and the prepolymer A249 and is made of a natural and renewable resource, cure in the environment conditions, not aggressive to man and the environment, and a national technology. The results showed a good performance of this adhesive, a good technical alternative for the technology utilization of GLULAM in timber structures with reforestation species.

Med den rådande befolkningsökningen tyder prognosen över bostadsförsörjningen att de behövs byggas fler bostäder för att uppfylla bostadsbehovet. Byggnadsbranschen står idag för cirka 20 % utav det totala koldioxidutsläppen i Sverige. Av detta skäl finns det ett behov att utveckla mer miljövänligare och hållbara tekniker för att uppfylla de ställda kraven gällande hållbart byggande. Trä och konstruerade träprodukter anses vara ett miljövänligt material och bör användas som stommaterial i byggnader i större utsträckning än det görs idag.    Detta arbete innefattar att jämföra de strukturella prestanda hos limträbalkar och armerade betongbalkar i flervåningsbyggnad. Som startpunkt modelleras en befintlig byggnad utifrån de dokument som tillhandhålls av ritningar och andra anvisningar för den avsedda referensbyggnaden. Bärverksanalysen utfördes i FEM-design till syfte att kontrollera limträbalkar beteende i nedböjning, spänning, tvärsnittsmått och bärighet. Arbetet genomfördes i två steg, referens byggnadens betongkonstruktion modelleras noggrant i första steget. I det andra steget ersätts armerade betongbalkar av limträbalkar i syfte att jämföra deras strukturella prestanda.     Det erhållna visar att limträets lätta vikt medför en minskning på ca 24 % på byggnadens totalvikt. Styvhetsegenskaper är limträbalkar största nackdel jämfört med armerad betongbalk, eftersom ett utbytte av balkarna med liknande dimension i 8 m spännvidd gav upphov till ca 65 % ökning på deformationer. Vid användning av limträbalkar ska spännvidden på 8 m halveras, samt större limträtvärsnitt och pelare placeras ut för att uppfylla det ställda kraven gällande bruks-och brottgränstillståndet. / With the prevailing population increase, the forecast of housing supply indicates that more housing needs to be built to meet the housing need. The construction industry today accounts for about 20% of the total carbon dioxide emissions in Sweden. For this reason, there is a need to develop more environmentally friendly and sustainable technologies to meet the set requirements regarding sustainable construction. Wood and constructed wood products are considered an environmentally friendly material and should be used as frame materials for buildings to a greater extent than is done today.   This work includes comparing the structural performance of glulam beams and reinforced concrete beams in multi-story building. As a starting point, an existing building is modeled on the basis of the documents provided by drawings and other instructions for the intended reference building. The structural analysis was performed in FEM design for the purpose of checking the behavior of glulam beams in deflection, stress, cross-sectional dimensions and load-bearing capacity. The work was carried out in two stages, the reference building's reinforced concrete structure is carefully modeled in the first stage. In the second stage, reinforced concrete beams are replaced by glulam beams in order to compare their structural performance.   The results show that the light weight of glulam leads to a reduction of about 24% in the total weight of the building. Rigidity properties are the biggest disadvantages of glulam beams compared to reinforced concrete beams, since a replacement of the beams with a similar dimension in 8 m span gave rise to about 65% increase in deformations. When using glulam beams, the span of 8 m must be halved, and larger glulam cross-sections and columns must be placed to meet the set requirements regarding serviceability and ultimate limit states.

The majority of research on high strain-rate effects in timber structures has been limited to the study of the load-bearing members in isolation. Limited work has been conducted on timber connections and full-scale timber assemblies under blast loading, and these have generally been constrained to qualitative observations. In North America, the increasing prevalence of mid- and high-rise timber structures makes them susceptible to blast effects. In addition, questions remain on how to design and optimize these timber assemblies, including the connections, against blast loads, due in part to the limitations on comprehensive design provisions. The effects of far-field blast explosions were simulated using the University of Ottawa shock tube. A total of fifty-eight dynamic tests were conducted on connection-level and full-scale specimens. The research program aimed to investigate the behaviour of heavy-timber connections when subjected to simulated blast loads. The experimental results showed that connections with a main failure mechanism consisting of wood crushing experienced significant increases in dynamic peak load when compared to the static peak load. In contrast, connections where steel yielding and rupturing occurred experienced no statistically significant increase in dynamic peak load. Full-scale glulam specimens with bolted connections designed to yield via wood crushing and bolt bending performed better than those with overdesigned connections. Bolted connections which failed in splitting led to premature failure of the glulam assembly. Reinforcement with self-tapping screws allowed these bolted joints to fail in a combination of bolt yielding and wood crushing, and provided more ductility when compared to unreinforced specimens. Specially designed energy-absorbing connections significantly increased the energy dissipation capabilities of the timber assemblies. The basis of these connections was to allow for connection yielding while delaying failure of the wood member. This was achieved via elastoplastic connection behaviour, which effectively limited the load imparted onto the wood member. Based on the experimental results, limitations in the current Canadian blast provisions were highlighted and discussed. A two-degree-of-freedom blast analysis software was developed and validated using full-scale and connection-level experimental results and was found to adequately capture the system response with reasonable accuracy. Sensitivity analyses regarding the applicability of using single-degree-of-freedom analysis were presented and discussed.

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I takt med att fler stora byggnader uppförs i trä ökar medvetenheten om resurshantering. Förbanden i dagens träbyggnader sågas isär och bränns vid rivning på grund av att förbandet inte går att demontera. Demonterbara förband skulle möjliggöra flyttandet av byggnader eller materialåteranvändning av bärande element. För att svara på forskningsfrågan ”Hur kan förband i limträkonstruktioner utformas, med dagens gängse beräkningsmetoder, för att möjliggöra demontering?” studeras en hallbyggnad som projekterats av Sweco. Två förbandstyper, pelar-balk och balk-balk, väljs för utformning av demonterbara förbandslösningar. Flexibel aktionsforskningsmetod har använts i problemlösande syfte. Insamlade data består av kvalitativa dialoger med sakkunniga och kvantitativa beräkningar.  Resultatet av studien är utformningen av två förband med genomgående skruvar. Pelar-balk-förbandet utformas med 8 genomgående skruvar, trälaskar och en invändig ståldymling. Balk-balk-förbandet utformas med en dold balksko med sidoplåtar och totalt 17 genomgående skruvar. Utformningarna med genomgående skruvar anses enkelt demonterbara och dessutom bra ur arbetsmiljösynpunkt. Pelar-balk-förbandets ursprungliga utformning har 72 träskruvar, vars skruvskallar döljs helt av trä och därför inte kan dras ut. Balk-balk-förbandets ursprungliga utformning består av 322 ankarspikar och 26 träskruvar som på grund av förbindarnas antal gör demonteringen så tidskrävande att den inte skulle utföras alls.  Examensarbetet landar i slutsatsen att det går att utforma förband för demonterbarhet genom att välja bort spik och träskruv till förmån för genomgående skruv. Förbanden som tagits fram under studien rekommenderas i byggnader där demonterbarhet eftersträvas. / As more large buildings are built in wood, awareness of resource management increases. The joints in today's wooden buildings are sawn apart and incinerated during demolition due to the fact that the joint cannot be disassembled. Demountable joints would enable the relocation of buildings or the reuse of load-bearing elements. To answer the research question "How can joints in glulam constructions be designed, with today's common calculation methods, to enable disassembly?" an industrial building designed by Sweco is being studied. Two joint types, column-beam and beam-beam, are selected for the design of demountable joint solutions. Flexible action research method has been applied in order to solve a problem. Collected data consists of qualitative dialogues with experts and quantitative calculations.  The result of the study is the design of two bolted joints. The column-beam joint is designed with 8 bolts, external wooden straps and an internal steel dowel. The beam-beam joint is designed with a hidden beam shoe with side plates and a total of 17 bolts. The designs with bolts are considered to be easily dismantled and also good from a work environment point of view. The original design of the column-beam joint has 72 wood screws. The screw´s heads are completely enclosed by wood and therefore cannot be pulled out. The original design of the beam-beam joint consists of 322 anchor nails and 26 wood screws which, due to the number of connectors, make disassembly so time-consuming that it will not not be performed at all.  This report conclude it is possible to design joints for disassembly by opting out of nails and wood screws in favor of bolts. The joints developed during the study are recommended in buildings where disassembly is wanted. / <p>Betyg 2021-06-04</p>

Today, a lot of resources are put into researching technological solutions concerning “carbon neutral” displacement materials and products, with the common goal of mitigating the amount of carbon dioxide in the atmosphere. The aim of this study was to find out whether a displacement of concrete to glulam beams, in the construction industry, could create substitution effects that reduces the amount of carbon dioxide in the atmosphere. To go about this, interviews were conducted with one producer of glulam beams, four construction companies and a non-profit foundation that funds research in fire prevention. Furthermore, sustainability declarations of glulam beams from three glulam beam producers, were analyzed. To compare carbon dioxide emissions in different scenarios, the interview results, as well as the sustainability declarations of the glulam beam producers, were compared and examined. Calculations of carbon dioxide sequestered in glulam beams and emitted from the concrete industry in Sweden were also regarded. The results showed that the possible substitution effects derived from a displacement of concrete to glulam beams, would have a small mitigating impact on the amount of CO2 in the atmosphere. However, recent findings point out that the pay back period for harvested trees, is longer than assumed. Moreover, the concrete production is not decreasing, but increasing. In respect of Jevons’ paradox (which concludes that higher efficiency in production leads to more consumption, not less), the conclusion of this study, was that no substitution will mitigate enough CO2 in the atmosphere. Our approach to consumption is what must change.

Large-dimensional wooden products are highly demanded within the construction sector. Theprimary motive of the thesis is to find a solution to connect small timber elements by meansof special steel devices. It is auspicable that the resulting hybrid structure could match theload-carrying capacity of a corresponding homogenous timber element with the same size.The focus in this thesis is to study one type of shear-key connection. Three types of beams(pure glulam beam, hybrid beam either with or without the splice connection at mid-span) arestudied regarding their structural behaviours by means of theoretical analysis, numericalmodelling and experimental tests.Hybrid beam without the splice connection shows higher bearing capacity and higher stiffnessthan pure glulam beam no matter which method is used. The structural behaviours for hybridbeam without the splice connection obtained from each method are more or less similarexcept the failure mode.Hybrid beam with the splice connection shows the bearing capacity higher than pure glulambeam but lower than hybrid beam without the splice connection. The stiffness for hybrid beamwith the splice connection is approximately the same as that of the pure glulam beam basedon analytical and numerical calculation. However, around 30% - 40% lower stiffness isachieved in experiment. Factors that might influence the result are discussed in the main text.Two analytical methods (Partial composite action (PCA) Method and Gamma Method) areutilized for hybrid beam without the splice connection. Although Gamma method is asimplified method, the results are similar with that from PCA method. Therefore, GammaMethod is reliable to be used for the hybrid beam without the splice connection in this thesisproject.In addition, it is found that the alignment of shear-key connectors, slip modulus betweenshear-key and notch, diameter of rod and the vertical distance between glulam and rod areconsidered as the main sensitivity parameters that would influence the structural behaviours for hybrid beams a lot.

The interest of timber structures has in recent years increased, primarily due tothe environmental benets of timber. This has created an increased demand forstructural engineers with timber expertise. At the same time the concept of structuralparametric design have become more popular. This new way of working withdesigns enables for architects and engineers to explore dierent geometries in earlystages of a project. However, the combination of a parametric workow and timberdesign have so far been limited due to the complexity of the material.This thesis aims to create an parametric workow within the visual programmingenvironment Grasshopper. This enables analysis of structural design simultaneouslywith a cross sectional and topological optimization of timber structures. The structuralanalysis is performed with Karamba which is a plug-in tool to the Grasshopperenvironment. The design verication based on Eurocode EN-1995 have been manuallyscripted in python components. The parametric model have been applied to acase where the main bearing bearing of a glass roof is to be designed. Three dierentgeometries have been evaluated with regard to cross sectional dimensions andgeometrical shape.The framework with a truss turned out to be a preferable design if only consideringweight, deection and utilization. The truss frame provides the lowest weight and thesecond smallest displacement. Furthermore, a comparison of the structural analysisand design have been performed with the FEM-program Robot. The compassionshow similar results, increasing the reliability of the Grasshopper model and theresults from this tool. It conrms it is possible to perform generative design oftimber structures within the same interface.The Grasshopper model is limited and can not handle all variations of 2D timberstructures. The complexity and variation of such calculations in conjunction with theEurocode have not been implemented during the time-span of this thesis. However,it is general within the limitations of the case study meaning a variety of framegeometries can be evaluated.

Med fokus på kunskapsbyggande utanför skoltid etableras en efter-skolan-utbildning med fokus på återbruk och reparation. Genom årskursens projekt växte en bild av att frånvarande av kunskap och fritidsaktivitet bidrar till utanförskap och social segregation som tär på samhällets fogar. Till ungdomar i närheten, främst från Nickstahöjden men också Grönsdal som är socioekonomiskt utsatta anläggs ett “hus för folket” + en återbruksskola för att bidra till att bredda utbudet av utbildningsfaktorer samt stärka faktorn av samhörighet och värdeskapande för deltagarna. Utbildning och kunskaplyft i alla dess former är nyckeln till en bättre morgondag. / With a focus on knowledge building outside of school hours, an after-school education is established with a focus on reuse and repair. Through the year's project, an image grew that the absence of knowledge and leisure activity contributes to exclusion and social segregation, which eats away at the joints of society. For young people in the vicinity, mainly from Nickstahöjden but also Grönsdal who are socio-economically vulnerable, a "house for the people" + a recycling school will be built to help broaden the range of educational factors and strengthen the factor of togetherness and value creation for the participants. Education and knowledge raising in all its forms are the key to a better tomorrow.