Operational modal analysis, OMA, results in unscaled mode shapes, since no forces are measured. Yet, obtaining a scaled modal model, i.e. knowing the modal mass of each mode (assuming proportional damping), is essential in many cases for structural health monitoring and load estimation. Several methods have therefore recently been developed for this purpose. The so-called OMAH method is a recently developed method for scaling OMA models, based on harmonic excitation of the structure. A number of frequencies are excited, one by one, and for each frequency, one or more frequency response values are calculated, that are then used for estimation of the modal masses of each mode, and residual effects of modes outside the frequency of interest. In the present paper, measurements were made on a four-story office building which was excited with a small, 200 N sine peak electrodynamic shaker. It is demonstrated that this small shaker was sufficient to excite the building with a force level of approx.. 1.8 N RMS close to the first eigenfrequency of the building, which was sufficient to produce harmonic response across the building. Reliable modal masses were possible to obtain within an accuracy of 6%. This demonstrates the feasibility of the OMAH method.

In softwood species, annual ring width correlates with various timber characteristics, including the density and modulus of elasticity along with bending and tensile strengths. Knowledge of annual ring profiles may contribute to more accurate machine strength grading of sawn timber. This paper proposes a fast and accurate method for automatic estimation of ring profiles along timber boards on the basis of optical scanning. The method utilizes two 1D convolutional neural networks to determine the pith location and detect the surface annual rings at multiple cross-sections along the scanned board. The automatically extracted rings and pith information can then be used to estimate the annual ring profile at each cross-section. The proposed method was validated on a large number of board cross-sections for which the pith locations and radial ring width profiles had been determined manually. The paper also investigates the potential of using the automatically estimated average ring width as an indicating property in machine strength grading of sawn timber. The results indicated that combining the automatically estimated ring width with other prediction variables can improve the accuracy of bending and tensile strength predictions, especially when the grading is based only on information extracted from optical and laser scanning data.(C) 2022 The Author(s). Published by Elsevier Ltd.

This paper proposes a one-dimensional convolutional long short-term memory (1D-CNN-LSTM) model for estimating the pith position and average ring width in Norway spruce timber boards. The model predicts these crosssectional parameters by processing sequences of light-intensity signals derived from optical scans of the board's four surfaces. The dataset used for training the model consists of synthetic boards sawn from simulated 3D logs. The model was evaluated on a dataset consisting of 552 end cross-sections from actual Norway spruce boards. Comparisons between the automatic and manual pith and ring width estimations demonstrated a very good accuracy. The computational speed of the model was more than twice as fast as the quickest method available in the literature. A large set of boards was then used to determine the advantages of incorporating the automatically determined average ring width in formulating indicating properties for machine strength grading. This evaluation revealed that the average ring width could, in certain situations, compensate for unknown variables such as density or resonance frequency in predicting the tensile and bending strength of Norway spruce boards.

Internationally, an annual number of more than a million fatalities are caused by road traffic crashes, with particularly signalized intersections being crash prone locations within the highway system. An accumulation of conflicts between drivers is caused by the  different  movements  (through  and  turning)  from  different  directions  at  the  intersection;  hence,  studying  the  trajectories  of  turning vehicles is an important step towards improving traffic safety performance of these facilities. In view of that, the current paper aims at providing further insight into the behaviour of left-turning vehicles (right-hand traffic rule) at signalized intersections in the State of Qatar. At first, a total of 44 trajectories of free-flowing vehicles were manually extracted from a recorded video for a  single  approach  of  Lekhwair  signalized  intersection  in  Doha  City,  State  of  Qatar.  After  that,  the  extracted  trajectories  were statistically analysed in an attempt to explore the factors affecting the path of left-turning vehicles at signalized intersections. The results suggest that the characteristics of the extracted paths are significantly related to the vehicle’s entry speed, minimum speed throughout its turning manoeuvre, and the lateral distance between the exit point and the curb (i.e., targeted exit lane). Provided that the speed parameters can be fairly an indication to the driving behaviour, it can be concluded that the driver’s attitude plays an important role in drawing the manoeuvre of a turning vehicle as does the pre-selection of the exit lane. Finally, the effort presented in this paper can be regarded as a way forward towards understanding the behaviour of turning vehicles at signalised intersection in the State of Qatar.

This paper aims at developing a convolutional neural network (CNN)-based tool that can automatically detect the left-turning vehicles (right-hand traffic rule) at signalized intersections and extract their trajectories from a recorded video. The proposed tool uses a region-based CNN trained over a limited number of video frames to detect moving vehicles. Kalman filters are then used to track the detected vehicles and extract their trajectories. The proposed tool achieved an acceptable accuracy level when verified against the manually extracted trajectories, with an average error of 16.5 cm. Furthermore, the trajectories extracted using the proposed vehicle tracking method were used to demonstrate the applicability of the minimum-jerk principle to reproduce variations in the vehicles’ paths. The effort presented in this paper can be regarded as a way forward toward maximizing the potential use of deep learning in traffic safety applications.

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. 

In the construction sector today, there is a lot of discussion about material reuse tominimize the negative environmental impact. By reuse of precast concreteelements, significant amounts of CO2 emissions can be prevented. In order toreuse a concrete element for structural purposes in a building, the element need tobe assessed to ensure it can withstand the required loads.

This report is based on a comparison of different building codes, it describes andcompares three selected building codes and their associated concrete standardsfrom different eras. The purpose of the report is to compare the results obtainedwhen designing predetermined concrete elements and components. The findingswill indicate whether it is possible to reuse concrete elements that were designedaccording to previous standards. The calculations will demonstrate bothsimilarities and, more importantly, differences in the design approaches of thebuilding codes and how they have evolved.

An investigation concludes that by employing a chain of checks, it is possible todetermine if an existing component is reusable considering its load capacity.

The differences in reinforcement content vary within approximately 0-25% infavor of the previous code, i.e. the older code requires more reinforcement.

Wind-induced dynamic excitation is a governing design action determining size and shape of modern Tall Timber Buildings (TTBs). The wind actions generate dynamic loading, causing discomfort or annoyance for occupants due to the perceived horizontal sway, i.e. vibration serviceability problem. Although some TTBs have been instrumented and measured to estimate their key dynamic properties (eigenfrequencies, mode shapes and damping), no systematic evaluation of dynamic performance pertinent to wind loading had been performed for the new and evolving construction technologies used in TTBs. The DynaTTB project, funded by the ForestValue research program, mixed on site measurements on existing buildings excited by mass inertia shakers (forced vibration) and/or the wind loads (ambient vibration), for identification of the structural system, with laboratory identification of building elements mechanical features, coupled with numerical modelling of timber structures. The goal is to identify and quantify the causes of vibration energy dissipation in modern TTBs and provide key elements to finite element models. This paper presents an overview of the results of the project and the proposed Guidelines for design of TTBs in relation to their dynamic properties.

Cross Laminated Timber (CLT) has in recent years become a more important building material. This means that the demand for accurate calculation methods in building standards such as Eurocode 5 has increased. There is limited knowledge about the connections in CLT buildings which is an important part of a CLT structure. This thesis was therefore focused on investigating a wall-floor-wall type connection commonly found in platform type buildings. 

An experimental and numerical study on typical wall-floor-wall connections was carried out in this thesis. In the experimental part 60 tests with 8 different configurations were conducted to investigate the influence of different parameters on the connection, moment capacity and rotational stiffness. During the tests the deformation of the specimens under four load levels were investigated. Compression tests were also performed on the specimens to determine the compressive strength and stiffness of the elements. In the numerical part two different models for the connection were created. One simplified model with rotational springs and one more complex model with compression springs. With these models the influence from the number of stories, span and thickness of the wall on the global behavior of a structure was investigated. 

The result from this thesis shows that there is both moment capacity and rotational stiffness in the wall-floor-wall type connection that can be utilized in the design phase of a structure. This was proven by both the experimental and the numerical study. The parameters that influence the behavior of the connection most were the load level applied on the wall and the wall thickness. The model created in the numerical study showed great potential regarding the replication of the connection behavior observed in the experimental study.  

The countryside is an important part of our society and a resource that can contribute to long-term sustainable development. However, there are prevailing problems in rural areas such as the closure of schools and reduced public transport. In recent times, there have been positive initiatives in rural areas. 

The work aims to inspire about the countryside and society by pointing to positive initiatives but also highlighting the problems and obstacles that exist in the countryside. The work is carries out in the form of interviews and a case study with three rural projects. The case study examined various projects and processes that are in time and how they can creare a more vibrant countryside. 

The results showed that positive initiatives together with the processes that lie in time can contribute to a more vibrant rural area. The rural projects in the case study together with the interviews show that there is potential for sustainable dimensions are affected in the various rural projects. 

The conclusions drawn are based on the results obtained from both the case study and the interviews. Based on the work, it can be seen that there are several factors such as synergies, entrepreneurship and grassroots innovation that affect the countryside positively but also what can contribute to more vibrant countryside. 

This article presents the further development of a tool for multi-phase reactive mass transport modelingfor durability estimation of cement-based materials, by the addition of the gas phase, adopting a trulyseparate two-phase moisture transport approach. The governing system of equations are based on phys-ically sound hybrid mixture based version of the Poisson-Nernst-Planck system of equations includinggaseous transport in the air-filled space, ionic transport in the liquid phase, electro-migration of ionicspecies, a two-phase moisture transport model, and sorption. The addition of the gas phase and thetwo-phase moisture description enables the user of the model to investigate individual and combinedeffects of different degradation processes in unsaturated systems. The altering of hydrated cement underthree different environments were studied representing an accelerated carbonation environment, a sub-merged marine environment and a cyclic drying-wetting zone in a marine environment, to illustratesome of the model’s capabilities.

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.

Here we illustrate the usefulness of using the chemical potential as the primary unknown by modeling isothermal vapor transport through a partially saturated cylindrically symmetric capillary tube of variable cross-sectional area using a single equation. There are no fitting parameters and the numerical solutions to the equation are compared with experimental results with excellent agreement. We demonstrate that isothermal vapor transport can be accurately modeled without modeling the details of the contact angle, microscale temperature fluctuations, or pressure fluctuations using a modification of the Fick-Jacobs equation. We thus conclude that for a single, axisymmetric pore, the enhancement factor depends upon relative humidity boundary conditions at the liquid bridge interfaces, distance between liquid bridges, and bridge lengths.

Precast concrete sandwich panels are widely used for building façades due to their energy-saving properties and durability. However, the joints in these façades are often considered weak points. This study investigates a one-stage sealing method for joints in a precast concrete sandwich façade panel system. It examines product manuals, design manuals, and professional opinions.

Sealants are classified according to ISO standards and EN standards, with silicone, polyurethane, and polysulfides being the most commonly used materials. A study of four sealants in the Swedish market revealed differences in material composition and operational conditions, although they demonstrated similar movement capabilities and curing temperature ranges. Additionally, the study reviewed the use of a backing strip and TDV pipe for draining joints. Calculating joint widths and depths using methods from Fog-och Brandskyddsföretagen, PCI/CPCI, fib, and Sika showed similar results, regardless of wall sizes.

A survey questionnaire was administered to construction industry professionals to gather their insights and experiences regarding joint design, sealant materials and applications, joint failures, and the longevity of sealed joints. Unfortunately, the survey did not yield the necessary number of responses, but it still provided some valuable perspectives from professionals.

Two templates were developed to calculate the minimum and maximum joint sizes due to tolerances and temperature changes. Template 1 uses the SFR rule of thumb to determine joint width, while Template 2 allows users to specify their preferred width. Both templates calculate the maximum joint movement capability. A series of calculations were performed using both templates and various wall sizes. Results from Template 1 suggest avoiding smaller precast concrete façade panels because of their significant joint movement capability. Conversely, if a consistent joint size is preferred, as with Template 2, it is advisable to avoid exceptionally large panels to prevent creating large joints and excessive movement capabilities.

The key findings from this study indicate that the SFR rule of thumb equation is reliable, as it produces results consistent with other equations. The sealants studied have similar application guidelines for façade sealing. Due to limited responses to the questionnaire, no definitive conclusions could be drawn about the long-term performance of the sealants. Walls exceeding 7000mm in length should be avoided, as they require larger joint sizes, leading to increased joint movement capability. Finally, it is recommended that performance-driven durability testing methods be developed, quality management systems be implemented by project stakeholders, and a new scientific survey be conducted.

Massive volumes of hazardous emissions have been produced by the construction sector for which some adequate steps are implemented, but the rising trend of emissions can still be seen. In this thesis, the goal is to identify and analyze renovation measures from primary energy use and environmental impacts perspective, according to Boverket’s mandatory provisions and general recommendations (BBR 2018), for an old school building. Also, as a part of the study goal, the building structure is analyzed under the updated Eurocode SS-EN 90-91-96 in order to see if the building meets structural stability requirements. Life cycle assessment of the building is limited to production and construction stages, and it is used as a tool to evaluate the environmental impacts according to standard SS-EN 15978:2011. Most of the relevant data are provided by VÖFAB, in cooperation with Växjö municipality, as well as the company WSP group.

The object of the thesis is an old three-story school building constructed in 1950 in Växjö, Sweden. The gross area of the building is 1,300 m2 and for renovation scenarios, building envelope components are investigated by adding new insulation materials considering two life cycle stages. In the production phase, the lowest primary energy use was 137 kWh/m2 for the scenario of using cellulose insulation material plus windows and exterior doors with a U-value of 1.1 [W/m2 K]. The lowest environmental impacts were also obtained for this scenario, with 14 kg CO2-eq/m2 global warming potential (GWP), 0.06 kg SO2-eq/m2 acidification potential (AP), and 0.06 kg NO3-eq/m2 eutrophication potential (EP). The results indicate that the share of the installation step in the primary energy use and environmental impacts during the construction phase is negligible, but the transportation role in this stage is significant. The highest global warming potential is for the scenario using cellulose insulation material plus windows and exterior doors with a U-value of 0.7 [W/m2 K] with 4.4 kg CO2-eq/m2 in the construction stage. Ultimately, the material production stage accounts for the most share of primary energy use and environmental impacts. 

This research provides several renovation measures investigated by life cycle assessment resulting in performing climate declarations. Regarding the sensitivity analysis, the electricity source has a considerable effect on reducing total primary energy consumption and environmental impacts during the production phase. It is also found that the scenario utilizing cellulose insulation material with windows with a U-value of 1.1 [W/m2 K] shows the lowest total primary energy use and environmental impacts. Through analyzing the building structure, all Eurocode criteria within the serviceability limit state (SLS) and ultimate limit state (ULS) are fulfilled, and the structure is still stable when new materials are added through renovation.

There are indications that the architecture in Sweden is perceived as more and more monotonous with the absence of aesthetic qualities. Architects are allowed to bear responsibility for the claim but they themselves believe that they deprived their position in the construction process where they are replaced under ongoing projects, ancillary financial interests.

The goal of the work was to find out what happens to a building's aesthetic qualities when the architect is replaced and what lies behind the replacement of the architect. A comparison of two objects was made, one in which the architect has been involved throughout the process and one where the architect has been replaced. The study was conducted through fact-finding from literature, observations and interviews.

The result shows that the desire to build beautifully with aesthetic qualities is strongly linked to the client's level of ambition. However, the overall result shows that aesthetic values are subordinated to the economy of the construction-process. Furthermore, it has emerged during the work with this essay that there is a lack of knowledge and difficulties in communication between the actors in the construction industry, especially between architects and contractors. 

In Sweden there are large differences between living in the city and the countryside. To make the countryside more attractive as a place of living, improvement is necessary in some regions. One such region is Skruv, a village that consists of a lot of deserted houses. 

The purpose of the study is to improve the living conditions in this region. As a result, a design proposal has been created.

In the creation of this study, both information gathered from field studies and interviews with subject relevant professionals has acted as a basis. This all surmised into a proposal with the old stationhouse as a central role. The proposal has a futuristic angle, as it expects there to be a functioning train stop, something which also increase the attractiveness of the region. In the proposal the chosen deserted houses consist of functions that are deemed desired by the inhabitants in Skruv. 

Overall functions in a society are the same regardless of the geographical location. It’s important to look at a place specific conditions and resources to enable a favorable development.

Rapporten behandlar hur husleverantörer kan utveckla presentationsmaterial. De materialen som visas är olika husmodeller från företagen och behandlar bakgrundsvyer samt förbättringar i digital media. Företaget som ligger till grund för rapporten är Trivselhus, och undersökningarna i rapporten är baserade på aktörer i anknytning till företaget. Resultatet kan även tillämpas hos andra husleverantörer.

Visualisering handlar om hur människan tar till sig den informationen som ges. Den används för att underlätta förståelsen för komplicerade bilder och idéer som visas för kunder. Visualisering möjliggör att bearbetade bilder kan kopplas samman med slutresultatet som presenteras.

Informationen som kommer genom visualisering kan fås genom människans fem sinnen syn, lukt, hörsel, smak och känsel. Denna studie lägger fokus på den synliga aspekten till visualisering och hur företag kan använda den för att förstärka sin kundkrets.

Resultatet ger exempel på visualisering som husleverantörer kan tillämpa i verksamheten. Det behandlar bland annat utveckling av hemsidor och gemensamma plattformar som kund och säljare båda kan arbeta i. Andra framtidsförslag som presenteras är en utveckling av visningshus samt producering av miniatyrhus. Detta för att ge kunden en bättre visualisering och därmed en större insyn i hur det färdiga huset är utformat och kommer fungera i verkligheten.

The foundation of the circular economy in the construction sector is based on implementing the deconstruction and reuse of buildings, providing the potential for a closed loop of building materials within the supply chain. Mass timber buildings using large, prefabricated elements and certain types of reversible mechanical connections are deemed to have great potential for post end-of-life (EoL) options, including recycling and reuse. To fully characterize the benefits of reusing post-use mass timber in new construction projects, it is crucial to conceptualize a ‘grave-to-gate’ approach, including the complete analysis of post-EoL activities and impacts on the material’s second life. In this study, a comparative life cycle assessment (LCA) including different EoL and post-EoL options for a virtual reference mid-rise mass timber building in the Pacific Northwest (PNW) of the United States was conducted. Among four different deconstruction and reuse scenarios examined in this study, a case of nearly complete reconstruction of a mass timber building for the second service life used as an idealized reference established an optimistic limit for reduction of global warming potential (GWP) by 13-41% compared to the ‘demolish and landfill’ decision, depending on the scenario. The demolition and landfill scenario had the lowest net impact since the GWMP calculations accounted for the carbon storage benefits in the landfill in addition to the carbon stored in the building.

The building and construction sector is a major contributor to human environmental impact on the planet. It follows that the sector's contribution is also crucial for transition towards a low carbon society and circular economy (CE). Mass timber products, are one of the sustainable alternatives to traditional building materials and have led to the recent revolution in timber construction. While environmental benefits of mas timber manufacturing and construction is well documented the end-of-life (EOL) and the post-EOL options for mass timber buildings, their environmental benefits and CE potential are discussed much less. Short history of construction technology involving prefabricated mass timber panels compared to traditional building types results in virtually no documented cases of panelized mass timber structures reaching the EOL stage and no practical examples of incorporating CE concepts in such projects. In this study, a two-step systematic literature review was used, to define and classify 23 CE-based governing principles from six categories in the construction industry, and to use those principles to analyze the state-of-the-art circular approach in mass timber research. The study covered a total of 90 papers, of which 68 focused on the general construction industry and 22 specifically on the mass timber construction. Results of this review suggest substantial gaps in knowledge and pressing research needs for the development of holistic approaches to prepare the mass timber construction for circular economy.

This thesis explores the effect of various parameters on the glue line strength ofglued Norway spruce (Picea abies). This is not only relevant for the production of engineered wood products, like e.g. glulam, but also for the production of blockglued elements, like ribbed floors. The study aims to optimize the productionprocess of block-glued elements by examining the impact of glue line pressure, pressing time, surface temperature and moisture content.

The method used is tensile shear tests on glued spruce specimens, conducted inaccordance with EN 302-1:2023. The glue line's performance is evaluated by measuring its tensile shear strength in lap-joint assemblies and assessing the percentage of wood failure, as specified in EN 314-1:2004. This standardized approach allows for studying the effect of various gluing parameters by comparisonof the results from related test series.

The results showed that the lower moisture content had insignificant effects on shear capacity. When pressing times were longer and a primer was used, the improvement was small with further improvement when pressing time is longer. However, atlower temperatures, there was a significant increase in strength compared to the reference. The strength improved when pressing times were extended. Lower temperatures or moisture content with longer pressing times led to better results than using primer with lower temperatures and moisture. When the pressure was lower, the strength of the elements decreased significantly and the results are only indicative and not proven statically significant. 

Rapid climate changes have increased the importance of environmental concerns,particularly within the construction industry, which faces substantial challenges to reduceits environmental footprint. Shifting from high-emission building materials to sustainablealternatives stands as a critical strategy to reduce climate impact. Previous studiesdemonstrate that timber structures produced lower greenhouse gas emissions compared tonon-timber options like concrete and steel.

CLT and its connections face a shortage of broad understanding and specific guidelines,notably in protected outdoor usage. Ambiguities in structural standards result inuncertainty, potentially leading to suboptimal outcomes and needless expenses. Toaddress these challenges, this study aims to bridge knowledge gaps by investigating steelto-CLT connections under cyclic moment loading and analyzing moisture content inoutdoor applications to determine appropriate climate classifications. Two experimentswere carried out: one indoors, evaluating cyclic moment loading's effects on steel-to-CLTconnections, and another outdoors, focusing on moisture development in CLT regardingsurroundings temperature and humidity.

Results indicate noticeable stiffness variation due to cyclic loading, relaxationphenomena, and moisture content variations. This study offers valuable insights intounderstanding the structural behavior and moisture dynamics of steel-to-CLTconnections, which are critical for informed decision-making in the sustainable design ofsteel-to-CLT connections in protected outdoor applications.Keywords: moment loaded CLT connections, CLT connections, cyclic moment loading,moisture content, moisture content variation. 

Compression perpendicular to the grain (CPG) of wood is a typical loading situation in timber structures. It has been an extensively studied research topic for decades, due to the highly ductile behavior of wood under such loading, the large variations in mechanical properties, and the relevance of these properties in structural design. Among others, the main influencing factors for CPG properties are stressed volume, load and support configurations, and annual ring orientations to the loading direction. After the innovation of the massive, engineered wood based product, cross-laminated timber (CLT) and its application in high rise buildings, CPG of wood has gained further importance. The development of a non-homogeneous, undesired and combined stress state under CPG in solid wood, due to the material anisotropy in the radial-tangential plane, can build up a complex multi-axial stress state in CLT. As a comparatively new product, the study of the influencing factors for CPG properties of CLT, and an understanding of the local material behavior under such loading, is essential for product characterization and for the development of design guidelines to ensure safe and efficient design.

The main aim of the doctoral thesis is to establish a relationship betweenthe anisotropic behavior of clear wood in the transverse plane and the structural response of CLT under CPG loading. Both experimental and numerical studies were adopted herein, to enhance the understanding of the basic material behavior and the product and structural behavior. On the clear wood scale, the focus was on developing a test setup for uniaxial and biaxial loading in the radial-tangential(RT) plane. The potential of the developed test setup for the biaxial testing in the transverse plane was exploited for the investigation of the moisture and time dependent behavior of clear wood under radial compression and rolling shear loading. For data acquisition, in addition to the force and displacement data measured by the internal actuators of the testing machine and an external load cell,a contact-free digital image correlation (DIC) system was used in the experimental investigations. A numerical model was developed, which can describe the elasto-plastic behavior of wood under compression in the transverse plane and predict the structural behavior of solid wood and CLT. For that purpose, a novel Quadratic multi-surface (QMS) failure criterion and a simplified Hoffman failure criterion were implemented in a user-subroutine in the finite element software Abaqus®, and their suitability was compared with the Abaqus implemented Hill’s criterion.The validation of the material models was based on the experimental investigations of failure behavior of clear wood under stress perpendicular to the grain with rolling shear interaction. The material models were further utilized to predict the structural response of solid wood and CLT wall-to-floor connections under CPG loading. The predicted response of CLT connections under CPG by using the above-mentioned material models was compared with experiments, which investigated the influences of different connection types, wall and floor thicknesses, positions of walls, and outer deck layer orientations. The models were then applied to investigate the influence of the pith location in the boards, the number of layers and the thickness of walls and the floor on the stiffness and strength of CLT connections. Moreover, the CLT connection’s rotational rigidity as a consequence of compressive force from the upper floor in a multi-story building was studied by means of finite element calculations.

The DIC measured strain fields from the experiments on clear wood confirmed the dependence of strain field on the curvature of the annual rings. As regards the material models, Hill’s model resulted in significantly higher force carrying capacity than experiments on clear wood, whereas Hoffman’s and QMS models predicted reasonably well the force-displacement relationships as found in experiments. The Hoffman’s and QMS models predicted stiffness was about 5–10% higher than corresponding experimental results on clear wood, and about 25% higher for CLT connections. The higher difference in the latter case is due to the difference in material properties of clear wood and structural timber, and the contact behavior between the structural members. The results from CLT wall-to-floor connections revealed a strong influence of loading and supporting configurations, wall thickness and pith locations on their stiffness and strength. A compressive loading on the CLT wall showed a positive effect on the rotational stiffness of CLT wall-to-floor connections, which considerably reduces the CLT floor mid-span deflection in comparison to a simply-supported floor.The thesis work contributes to an enhanced understanding of the anisotropic material behavior of wood in the RT-plane and of its effects on structural timber and CLT under CPG loading. The outcomes of the thesis are beneficial to the product design and standardization of CLT and can be applied in further product development and in optimized structural design.

The anisotropic material behavior of wood, considered as a cylindrically orthotropic material with annual rings, leads to several different failure mechanisms already under uniaxial stresses. Stress interaction becomes important in the engineering design of structural elements and is often predicted by failure criteria based on uniaxial properties. The prediction quality of failure criteria has been assessed with longitudinal shear stress interaction, though less is known on rolling shear stress in interaction with stress perpendicular to the grain. The study aims at investigating the corresponding mechanical behavior of Norway spruce (Picea abies) clear wood by validating failure envelopes for stress combinations in the cross-sectional plane, based on experimental investigations. For this purpose, a test setup that controls the stress interaction and loading of clear wood along pre-defined displacement paths needed to be developed. Experimentally defined failure states could then be compared to failure surfaces predicted by the phenomenological failure criteria. Material behavior was quantified in terms of stiffness, strength, and elastic and post-elastic responses on dog-bone shaped specimens loaded along 12 different displacement paths. A comparison with failure criteria for two nominal compressive strain levels showed that a combination of failure criteria would be required to represent the material behavior and consider the positive effect of compressive stresses on the rolling shear strength. The findings of this work will contribute to studying local stress distribution of structural elements and construction details, where stress interactions with rolling shear develop.

The orthotropic material property in combination with ductility in compression, brittleness in shear and tension, very low shear modulus in radial-tangential (RT) plane etc. requires anisotropic stress failure criteria, as well as their evolution with increasing strains. Three- dimensional failure criteria have been proposed for this purpose, but their validation in the RT plane with interaction of rolling shear stresses has attracted less attention. Corresponding stress interactions are however important for modelling of engineered wood-based products under compression perpendicular to the grain when taking into account influence of the annual ring structure.

The work aims at defining failure envelopes for stresses perpendicular to the grain with rolling shear stress interaction based on experimental investigations performed on Norway spruce. The experimental set-up was realized in a biaxial testing frame and consisted of stiff steel plates to transfer load from the testing machine to wood specimen. Mechanical grips prevented rotation and uplifting of the specimen in case of pure shear and tensile loading, respectively. In addition to conventional linear variable differential transformers, a digital image correlation system was used to measure strain fields on the surface of wood specimens and steel plates. Measurements of dog-bone shaped specimens were carried out along different stress interaction paths by displacement controlled loading.

The experimental dataset was then compared with commonly used phenomenological failure criteria, namely Tsai-Hill, Tsai-Wu [1], Norris [2] and Hoffman, as well as with regression equations from previous works [3].Experiments revealed that the stress-strain relationship under compression, shear, and biaxial loading differs in radial and tangential directions. None of the three-dimensional stress failure criteria provided good prediction of experiments under compression and rolling shear, but experimental data was closer to the regression equation proposed in [3].

Wall-to-floor-to-wall connections are important for the performance of multi-storey, platform-type cross-laminated timber (CLT) structures. Their stiffness properties are studied by means of a numerical model, which was previously validated with experimental data from material testing and CLT connections loaded perpendicular to the grain. In this work, the stiffness of CLT wall-to-floor-to-wall connections is derived and its dependence on the compressive loading in the CLT walls and on wall and floor thicknesses were investigated. The compatibility of the local model with the connection size in structural design models, was investigated by studying the effect of the floor length and the wall height in the numerical model. The results showed that both rotational elastic stiffness and moment capacity of the floor connection increase with increasing compressive force on the CLT wall. However, a moderate decrease in stiffness, but a stronger rotation hardening was found for higher wall pressures, while lower wall pressures yielded an ideal plastic behaviour. The wall thickness showed a higher influence on the connection stiffness and moment capacity than the floor thickness. The influence of the support condition on the deflection of a CLT floor was exemplified. This study includes novel stiffness data for the design of CLT floors in platform type constructions.

Material properties of wood under compression perpendicular to the grain and rolling shear are important for the engineering design of timber structures. This regards the short-term stiffness and strength, their dependence on the moisture content of wood, as well as the time-dependent behavior. Norway spruce clear wood properties in the transverse plane of wood were studied inan experimental campaign exploiting an earlier developed biaxial test setup. The moisture dependence of the stiffness and strength and the short-term time-dependent creep deformations under compression in the radial direction and under rolling shear were characterized. Loading and unloading stiffness, as well as the strength, were determined in quasi-static tests at five different moisture contents from 4% to 29%. The elastic and viscous stiffnesses were identified in creep tests at three compressive stress levels of 0.50, 0.75, and 1.00 N/mm2, and at two rolling shear stress levels of 0.33 and 0.50 N/mm2. The test data complements the existing experimental database, especially with novel data regarding the moisture dependence of the rolling shear strength, which showed less moisture dependence than the compressive strength perpendicular to the grain. The results of the creep tests revealed different material properties for the different loading and material directions of wood.

The use of cross-laminated timber (CLT) in multi-story buildings is increasing due to the potential of wood to reduce green house gas emissions and the high load-bearing capacity of CLT. Compression perpendicular to the grain (CPG) in CLT is an important design aspect, especially in multi-storied platform-type CLT buildings, where CPG stress develops in CLT floors due to loads from the roof or from upper floors. Here, CPG of CLT wall-to-floor connections are studied by means of finite element modeling with elasto-plastic material behavior based on a previously validated Quadratic multi-surface (QMS) failure criterion. Model predictions were first compared with experiments on CLT connections, before the model was used in a parameter study, to investigate the influence of wall and floor thicknesses, the annual ring pattern of the boards and the number of layers in the CLT elements. The finite element model agreed well with experimental findings. Connection stiffness was over estimated, while the strength was only slightly under estimated. The parameter study revealed that the wall thickness effect on the stiffness and strength of the connection was strongest for the practically most relevant wall thicknesses between 80 and about 160 mm. It also showed that an increasing floor thickness leads to higher stiffness and strength, due to the load dispersion effect. The increase was found to be stronger for smaller wall thicknesses. The influence of the annual ring orientation, or the pith location, was assessed as well and showed that boards cut closer to the pith yielded lower stiffness and strength. The findings of the parameter study were fitted with regression equations. Finally, a dimensionless ratio of the wall-to-floor thickness was used for deriving regression equations for stiffness and strength, as well as for load and stiffness increase factors, which could be used for the engineering design of CLT connections.

Numerical modeling is an efficient tool for experimental validation and for gaining a deeper understanding of complex material phenomena, especially when causal relationships are overlaid by material variability. Wood is such a highly orthotropic and complex material, which in engineering problems however is considered as macro- homogeneous. The aim of this study is to numerically investigate stress and strain states of wood in the radial- tangential plane and the influence of the orthotropic material behavior on the structural response. Model vali-dation is based on experiments performed on clear wood of Norway spruce (Picea abies) by using a biaxial test setup. Three material models were used, namely Hill’s plasticity model, the Hoffman criterion and a novel quadratic multi-surface (QMS) criterion. After validation on the local material scale, the models were applied to the engineering problem of compression perpendicular to the grain for studying the effect of the unloaded length. As a novel part, the influence of the annual ring structure on the local material behavior and the global elasto- plastic force–displacement behavior of wood under compression perpendicular to the grain were numerically investigated. Hill’s failure criterion was found to be the least suitable at both length scales, local material behavior and global structural response. The Hoffman and the QMS criteria showed quite good agreement with the biaxial experiments in terms of force–displacement relations and strain distributions for different loading situations, especially for combinations with radial compression, while there was less agreement with experiments for  the  behavior of  combinations with tangential compression. Application of  these material models to compression perpendicular to the grain for studying the unloaded length effect yielded similar trends as observed in structural tests. A reasonable and similar force–displacement response by Hoffman and QMS criteria was observed, while Hill’s model yielded significantly overestimated force carrying capacity. Differences in force-–displacement response for different loading situations were well in line with literature findings and the infl-ence of the annual ring curvature on the overall force–displacement behavior could be quantified.

Plans for construction of the tallest residential timber building has driven the Technical Research Institute of Sweden (SP), Linnaeus University, Växjö and more than ten interested companies to determine an appropriate design for the structure. This thesis presents a part of ongoing research regarding wind-induced vibration control to meet serviceability limit state (SLS) requirements. A parametric study was conducted on a 22-storey timber building with a CLT shear wall system utilizing mass, stiffness and damping as the main parameters in the dynamic domain. Results were assessed according to the Swedish Annex EKS 10 and Eurocode against ISO 10137 and ISO 6897 requirements. Increasing mass, stiffness and/or damping has a favorable impact. Combination scenarios present potential solutions for suppressing wind-induced vibrations as a result of higher efficiency in low-increased levels of mass and damping.

Pedestrian bridges are designed with consideration for both static and dynamic loads, but dynamic loads are more critical for the structural dimensions and material selection of the pedestrian bridge. Depending on the usage and location, the bridge is constructed with the understanding that all movement activities affect it at different comfort levels. For example, a large group of individuals moving at a high frequency can generate greater dynamic vibrations compared to a single person walking or jogging.

The purpose of the study is to evaluate the vertical acceleration based on a number of tests, as well as to examine how a pedestrian bridge behaves under vibration loading. Additionally, the study aims to determine the modal parameters of the pedestrian bridge, such as natural frequencies and damping ratios. Damping is the energy loss in an oscillating system through the dissipation of kinetic energy, which leads to a reduction in amplitude at resonance frequencies.

The pedestrian bridge spans between the N and K buildings at Linnaeus University and is approximately 30 meters long. It is constructed of wood and concrete and is covered and glazed. By performing tests with different activities such as walking, running, and jumping on the bridge, acceleration, natural frequencies, and mode shapes have been evaluated. The results have been compared with the guidelines in Eurocode 5 and the French guidelines from Sétra.

Tests have been conducted using a data acquisition system and accelerometers placed along the bridge on both sides. The aim was to assess the behavior of the pedestrian bridge under vibrations and determine different comfort levels compared to Eurocode 5-2 and Sétra. The results show that the acceleration values for the tests are within maximum, medium, and minimum comfort levels. Additionally, the natural frequency falls within a range that minimizes the risk of resonance phenomena in the structure.

The interpretation of the results indicates that the properties of the pedestrian bridge meet the standards and guidelines, otherwise, the pedestrian bridge would have been improperly constructed. The results show that the pedestrian bridge is suitable for pedestrian activities, but there may be situations where students need to evacuate quickly, i.e., run on the pedestrian bridge, and in such situations, the structure of the pedestrian bridge is not negatively affected as it does not occur often where accelerations can be at a level that exceeds the recommended maximum levels in the lowest comfort class.

Floating-Slab Tracks (FST) are predominantly used for mitigating railway-induced vibrations where the concrete slab is mounted on soft resilient bearings to provide vibration isolation. This paper presents a research study on the dynamic behavior of a special type of FST used in the recently built subway system in Doha, Qatar. The special FST has a continuous concrete slab with periodic grooves. Therefore, the track can be modeled as a periodic structure with a slab unit having two elements with different cross-sections. Extensive numerical and experimental investigations were conducted on a multi-unit full-scale mockup track representing the special FST. A fast running model based on the Dynamic Stiffness Method was developed and examined, in an initial numerical exercise, against a detailed Finite Element model for a track with a finite length. In the experimental campaign, a test was performed with an impact hammer to identify the actual vibration response of the mockup track. Results from the experimental investigations were then used for model updating of the fast running model. The model updating process was carried out according to an automated hybrid optimization approach that combines genetic algorithms with a local search method. Finally, the updated model was extended to an infinite model to investigate the influence of varying grooves thickness on the dynamic behavior of the special track with infinite length for both bending and torsion scenarios. The investigations suggested that reducing the thickness below 50% of the full thickness of the slab significantly affects the dynamic behavior of the special FST.

More buildings are being built for various reasons nowadays. Constructing, maintainingand renovating buildings requires building materials in large amounts and this in turn canaffect the environment in many different ways.  

This work studies the sustainable aspects and consequences of construction, as well as theopportunities that can be found and can be developed to build more sustainably and findsolutions for the use of different buildings and building elements. This report focuses onexplaining and clarifying the conditions for the reuse and recycling of the entire buildingsand their prefabricated concrete elements. 

The report shows the advantages of building an increasingly sustainable society,especially in the construction industry, the difficulties that exist and can be encounteredon the way to creating it. The highest proportion of recycling of concrete structures is thereuse of the entire building, if the possibility of recycling the building does not exist thenthe next step will be to dismantle the building where a large amount of elements fromstructures can be used in the best possible way. 

The goal of creating a more sustainable construction society is to reuse/recycle thebuilding materials, especially concrete and the prefabricated elements. This could be donein different ways, such as crushing the element and separating it from its variousmaterials. Meanwhile this is not common in Sweden today, where companies prefer toeither reuse the entire element on another building or to keep elements and resell them tothe private market or to other companies. The recycling of the material is costly andtherefore many companies avoid doing it. 

Different types of connections have been studied in this study, to enable the reuse ofprefabricated elements, the advantages and disadvantages of these connections have beenmentioned and a comparison between these has also been made. The couplings mentionedin this report include bolted fasteners, welded fasteners and cast in place (wet) fastenersand reinforced (wet) fasteners that usually occur in combination with previous couplings.Several trials and study cases have been reported, these trials have been done in differentcountries such as Germany, Finland and the United Kingdom to get a betterunderstanding into how to work internationally with sustainability and assembly ofprefabricated elements.  

n this study, the design of the runway structure of the runways is studied in order tocompare different material compositions in the pavement. This is done with the helpof a survey, the program FAARFIELD and peer reviewed studies. Generally, thereare two different types of road structures in an airfield, rigid and flexible (concreteand asphalt). The result obtained shows the difference between the differentdimensions and the material content of the different types of road structures, whenthey are loaded with either heavy or light aircraft models. These results are based ona design period that has been selected for 20 years. In contrast, the stiffness of theconcrete was much higher than the asphalt stiffness, which means that it is better touse concrete in large commercial airports. According to the CDF diagram (thediagram showing whether the structural design conditions are met), the damagecaused by the aircraft is approximately at the same location on the runway for bothsuperstructures, it also means that flexible superstructure maintenance needs to bedone more often, compared to rigid superstructures. The fact that the asphalt has alower modulus of elasticity than the concrete is also a reason why maintenance forflexible superstructures needs to be done more often. However, when the roadstructures became heavily loaded, the total demanding thickness for the rigid roadstructure is calculated to be 760 mm and for the flexible road structure 710 mm.

This study was carried out in Backaryd’s church following a proposal from Ankdammen konsult. Backaryd’s church was built more than 200 years ago in Ronneby municipality in Blekinge County. Due to changes in heating methods and energy requirements since the church was built, the church today does not meet the energy and comfort requirements of today’s buildings. The study of the Backaryd’s church aims to investigate the floor construction in the church and to find out what factors may be at risk of moisture damage. The study will analyse the church and mainly the condition of the crawl space. In addition, some improvement measures will be proposed to get a comfortable heating inside the church with an appropriate energy use. Both law and society place high requirements on the preservation of valuable and cultural-historical buildings for future generations. In addition, any changes to churches that have been built before 1939 must be approved by the county administrative board.Results from the study show that relative humidity does not reach critical levels either in the crawl space or the church room. There are also no injuries such as mold and rot attacks on the structure. The inventory is of good quality and lacks damage such as cracks and rots.The writers have come up with the following improvement measures:● An annual entertainment of water management systems in crawl space. ● Cover the stone walls with plastic wrap on the inside and make them as dense as possible. ● Place the base of the panty bottom from below up against the floor beam. ● Insulate the floor structure with mineral wool. ● Place a plastic wrap all over the ground in the crawl space. ● install a dehumidifier. 

Ett behov finns av att fördröja dagvatten innan det släpps på det kommunala ledningsnätet för att minska flödestopparna och undvika överbelastning. Studien avser att ta fram en förenklad metod för val och utformning av LOD-metod som är anpassad för privata fastighetsägare.

Ett flertal LOD-anläggningar samt förutsättningar kring dessa har undersökts. Studien har gett en grundläggande information och en beräkningsgång som har förenklats, är lätt att följa och som kan anpassas efter befintliga förutsättningar och önskemål. 

The study aims to investigate water damage that has become increasingly common in Swedish buildings. Water damage exposes humans to health risks due to a high risk for microbial growth. The purpose of the work is to discuss water damage, where water damage occurs and why, what costs do the insurance companies cover and what costs do the property owners cover. The study also examines how different actors view water damage and risks with different types of frame material. The result of the study is that the insurance companies assess all frame materials equally in terms of compensation for water damage, that is, they treat wood and concrete frames in the same way. However, the age of the building is more decisive as they make age deductions to evaluate the compensation for the respective water damage. Damage should be remedied as soon as possible, the faster the damage is rectified the less water damage spreads. The method used in the work was a qualitative method and the reliability is considered high since the results are consistent with the theoretical starting points.

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. 

Södra DuraPulp is a relatively new eco-composite, made from natural wood fibers and polylactic acid (PLA), which comes from corn starch. Until now, there are only few applications for DuraPulp, mainly in the area of design. To find new fields of application, more knowledge about its mechanical material properties are of great interest.This study deals with characterizing the mechanical properties of DuraPulp in an analytical way by means of micromechanical modelling and evaluation with help of Matlab. The mechanical properties for PLA were taken from scientific literature. Not all properties of the wood fibers could be found in literature (particularly Poisson’s ratios were unavailable). Therefore, they partly had to be assumed within reasonable boundaries. These assumptions are later validated regarding their influence on the final product.Figures and tables were used to present and compare the in- and out-of-plane E-Moduli, shear moduli and Poisson’s ratios of DuraPulp. The calculated in-plane E-Moduli were then compared to those obtained from an earlier study, where DuraPulp was tested in tension. The results showed that experimental and analytical values are very similar to each other.

Den ökade användningen av BIM har ändrat villkoren inom byggsektorn. Arbetet syftar till att identifiera och definiera de krav och kvalitetssäkringar av BIM-objekt som finns inom projektering, produktion samt förvaltning. Avsaknad av en gemensam standard försvårar kravställning och kvalitetssäkring av BIM-objekt vilket har lett till vissa komplikationer, främst vid konvertering mellan olika programvaror.

BIM är med sin potential med största sannolikhet en stor del av byggsektorns framtid. För att kunna ta nästa steg i utvecklingen måste en gemensam standard gällande krav och kvalitetssäkring utarbetas.

Water is an essential resource, and its significance is growing with the global populationincrease. Historically, Sweden has had ample supplies of clean water, but futurechallenges in drinking water availability cannot be ruled out. To conserve the availabledrinking water, several approaches are possible, one of which is greywater recycling.Greywater refers to wastewater from baths, dishwashing, and laundry. This usedgreywater can be purified and then reused as flush water for toilets.

The purpose of this report is to investigate whether a greywater recycling system isfeasible to implement in an existing building, what investments are required, and whatsavings can be achieved. A greywater recycling system is designed, and a comparison ismade between a technical solution in an existing building versus a new building.Additionally, the potential of greywater recycling and the challenges involved areanalyzed.

In this work, a case study was conducted where a hotel building was analyzed. Theexisting hotel building served as the basis for the design of a greywater recycling systemin both the existing structure and in a theoretical new construction. Calculations of waterflows and pipe sizing formed the basis for the design of the greywater recycling system.Throughout the work, a literature review was conducted to expand the understanding ofthe subject. Furthermore, information was gathered from experts to investigate thegeneral possibilities and challenges of greywater recycling.

The results show that a greywater recycling system is designed the same way in anexisting building as in new construction. However, extensive measures are required in anexisting building when implementing a greywater system, which leads to it not beingoptimally feasible from an economic and sustainable perspective. Preliminary costestimates show that there is a significant economic difference between implementing asystem for recycling greywater in an existing building versus in a new construction. Themost commonly used purification system for greywater is a biological purificationprocess with filtration, which is also proposed in the designed system.

The analysis shows that there is potential for water savings through the recycling ofgreywater for toilet flushing, a method that is not only feasible but also aligns with theUN's goals for sustainable cities and communities. Currently, economic gain is difficult toachieve in a greywater recycling system. Installation and operational costs exceed theeconomic savings of water due to the current low water prices. However, potential futureincreases in water prices could mean that systems with greywater recycling could becomeeconomically advantageous. It is therefore important to continue developing thetechnology and the current laws and regulations concerning greywater recycling, tobroaden the possibilities for the use of recycled greywater.

Cross-laminated timber (CLT) is a rather new construction material that has increased its popularity and usage significantly within the building industry in the past years. In timber buildings, the connections are one of the most challenging parts to design. Thus, there are high demands put on structural engineers to make a safe and economic design. Today structural engineers have no specific and clear guideline that they can use as help for design of connections in CLT-buildings. By reviewing the most common CLT-handbooks, comparing them with each other, and picking out the best parts from each of the handbooks, a new guideline for design of connections in CLT-structures was developed in this thesis with complementary design examples. The guidelines main purpose is to act as help for the structural engineer when designing connections in CLT-structures. It is indented that the guideline acts as basis for the development of a future CLT-handbook with a collection of supporting calculation examples.

This work has been carried out to show how it is possible to combine accessibility in buildings of cultural heritage and historical value. In this case, three local buildings have been studied on Storgatan in Växjö, with a focus on people with reduced mobility. 

The work was carried out by studying laws that apply accessibility, making a site visit and interviewing experts on the subject. The goal was to come up with a proposal for each selected premises. Solutions should be able to be an inspiration to implement in real projects for buildings with the same characteristics.

The results of the study showed that there is a lack of accessibility in three selected entrances. Inaccessible buildings can mean restrictions for people with reduced mobility to be able to carry out daily activities. There is also a need to include accessibility in buildings that have a building memory.

Hybrid simulation is a numerical and experimental structural testing technique in which the critical structural members are tested experimentally, while the rest of the structure is modeled numerically. During hybrid testing, the numerical model is updated continuously based on the output of the experimental test. In this study, a quasi-static hybrid simulation was conducted on a steel truss structure. A single truss member was considered as the physical substructure, while the remaining members were modeled using Abaqus finite element software. The communication between the physical and numerical models was established using OpenFresco as a middleware. Using this setup, the structure was loaded until the physical substructure failed due to buckling. Finally, the results of the hybrid simulation were verified numerically and experimentally.

Over the past decades, there has been a rise in greenhouse gas (GHG) emissions into the atmosphere, thereby contributing to global warming and climate change. The building sector is among the top contributors to the world’s GHG emissions. In order to reduce GHG emissions, different strategies are being explored and investigated to provide a sustainable solution. In this thesis, the carbon footprint of a seven-story cross-laminated timber (CLT) building system is assessed and optimized from a life cycle perspective. The overall goal is to identify strategies to reduce the carbon footprint of the CLT building through material substitutions and optimized use of materials.

In this thesis, both life cycle assessment (LCA) and finite element method (FEM) using RFEM is carried out. A cradle-to-cradle life cycle assessment (LCA) of the building is conducted according to the European standard EN 15978. Life cycle inventory datasets from the Ecoinvent database are used for the analysis of the product (A1-3) and construction (A4-5) stages of the building, while environmental product declarations (EPDs) are used for the analysis of end-of-life stage. The service life stage of the building is analysed over a 100-year time horizon, considering the maintenance and replacement (B2 and B4) activities linked to the building. Because the CLT technology is relatively young, a web-based was carried out to gather additional data for the analysis of the building’s service life stage.

The finite element analysis using RFEM is used to ensure the stability of the CLT building system after reducing the CLT panel thicknesses. In, addition, relevant calculations are carried out based on different Eurocodes. In this process, deflection checks are performed for the slabs and buckling checks are carried out for the walls, as well as vibration (fundamental frequency) is made sure to satisfy the limits recommended for CLT structures.

The results show that the life cycle carbon footprint of the complete CLT building system is 489.8 kgCO₂-eq/m². Out of this, the production stage has the highest carbon footprint, accounting for 300 kgCO₂-eq/m². Optimizing the CLT panels' thickness in the floor, walls (interior and exterior), and roof reduced the carbon footprint of the building by 1.1% (from 300 to 296.6 kgCO₂-eq/m²). In addition, substituting cellulose fiber for mineral wool insulation reduced the product stage carbon footprint of the insulation in the building by 6.2% (227.5 to 213 kgCO₂-eq/m²). On the other hand, due to the density differences between mineral wool and cellulose fiber, a greater mass of cellulose fiber was required to achieve the same thermal insulation performance. Consequently, the transportation carbon footprint increased by 5.8% compared to when using the original mineral wool insulation. Therefore, a net carbon footprint reduction of 16.6 kgCO₂-eq/m² (5.5%) is achieved in the production stage (A1-5) when substituting cellulose fiber for mineral wool insulation.

The analysis shows that including biogenic carbon reduced the total carbon footprint of the structure by 62% (489.8 to 185.4 kgCO₂-eq/m²). Furthermore, the configuration of the floor of the structure, consisting of aggregates and CLT contributed significantly to reducing the carbon footprint of the building. The two strategies implemented in this study reduced the product stage carbon footprint by 7.3% (227.5 to 211 kgCO₂-eq/m²) and the total life cycle carbon footprint of the building by 2.7 % (489.8 to 476.5 kgCO₂-eq/m²).

The result shows that 45% of the respondents indicated that maintenance, replacement, repair, and refurbishment would not be necessary for the studied building, while 25% reported that these actions would be necessary twice within the building’s service life of 100 years. Based on these scenarios, carbon footprint of 21.3 and 72.9 kgCO₂-eq/m² may be attributed to maintenance and replacement of the building, respectively. The analysis shows that the end-of-life stage, including deconstruction and demolition, transport and material processing (C1-3) gives carbon footprint of 70.3 kgCO₂-eq/m².

This thesis results imply that optimized use of materials, using renewable materials (wood), and substituting non-renewable materials with renewable can give reductions in the carbon footprint of the studied CLT building system. In addition, in this study it is observed that conducting structural analysis of the CLT building is essential in order to get accurate results and for further trials of thickness reduction by prioritizing and confirming the stability of the CLT building system.

The climate impact from the construction and property sector has in recent years been adriving cause of emissions of greenhouse gases, which is a challenge for society. InSweden, the climate impact caused by the construction and real estate sector in 2020 hasbeen estimated at approximately 9.8 million tonnes of carbon dioxide equivalents, whichcorresponds to 21% of Sweden's climate impact. Sweden is a country that constantlyworks to reduce the climate impact from new buildings and as a result the governmenthas introduced requirements for climate declarations for newly constructed buildings.Climate declarations must cover a building's product stage (module A1 – A3), transport(A4), construction waste and energy consumption on the construction site (A5).

The thesis has been carried out with the help of the 3D modeling program Revit,Boverket's climate database and SundaHus's database. Revit was used to calculatematerial quantities to be included in the climate declaration. Boverket's and SundaHus'sdatabase was used to collect the material's climate data.

In the climate declaration, the total climate impact is reported, which corresponds to 545𝑘𝑔𝐶𝑂2𝑒/𝑚2𝐵𝑇𝐴. The result of the climate impact covers the modules concerning theconstruction phase, i.e. A1 – A5 where product stage A1 – A3 has amounted to 492,transport 28, construction waste 15 and energy 10 in 𝑘𝑔𝐶𝑂2𝑒/𝑚2𝐵𝑇𝐴.

The climate declaration act contributes to increased competence and understanding withinthe construction and property sector for how different materials affect the climate.Currently, there are no limit values to refer to when calculating the climate impact andtherefore it is difficult to assess the result. The calculations made reflect the estimatedvalue of hospitals supported by the standard values, which are estimated values regardingdiesel and heating oil at the construction site.

Detta examensarbete är utfört för att ge Växjö kommun ett underlag för utformning av en ny ÅVC på Häringetorp. Återvinningscentralen ska vara estetisk tilltalande för att öka trivsel för både brukare och personal. Vid utformning måste hänsyn till trafiksäkerheten tas för att undvika problem. Utformningen påverkar även sorteringskvalitén hos det sorterade avfallet, Resultatet uppnås genom att forska, granska och utreda. Utöver detta ska dessutom utformningen av återvinningscentralen påverka sorteringskvalitén på så vis att det ska vara enkelt konstruerat samt att det ska finnas en välbetänkt yta med utrymme för att sortera avfallet.