Production of one family houses has over time developed successfully in Sweden and producers have managed to reduce the production costs and industrialize the production process. The development has however not been that successful when it comes to high-rise buildings. There are many attempts made, but no one has really managed to create a product that can persuade the market. The systems used are not flexible and cannot cope very well with variations in the design. The aim of this work has been to develop and evaluate the idea of prefabricated high-rise buildings within the outlines of a scientific research. By understanding the problems that the building sector experiences today it will be possible to identify the solutions that are needed tomorrow. The main objective has been to develop new technologies and system concepts for buildings. Concepts that are highly flexible and respect the ambitions of the architect and technologies that will facilitate a more effective building process and address relevant key issues in building physics and building construction for cost reduction and a sustainable performance. Aside from the actual production cost it is also important to consider the lifecycle cost of the building. The production cost represents only a fraction of the total lifecycle cost of a building. A background research has been made to understand the building process and its problems, this information served for the formulation of a building concept. The work has been interdisciplinary and has not been limited to only one single point of view. Because of the nature of the method the work has resulted in new construction techniques. The initial idea of the prefabricated high-rise building has during the course of this work developed to a complete building concept. The Symphony Concept as it is called is about industrial prefabricated buildings that are assembled on site and is based on the idea of large and flat building elements with a very high degree of prefabrication. To evaluate the concept technology detailed researches have been made in different fields. The detailed researches made in this thesis regards the strength of sheet metal studs embedded in stiff insulation blocks, hazards connected with plastering on light weight constructions and fire protection of light weight constructions. The experiences from these researches are then applied in the building concept. Theory was put to practice with the construction of an experimental building called the Research Tower. The purpose of this pilot-project was primary to evaluate the construction technology and secondary to evaluate the properties of the building concept. To be able to find methods for production of sustainable, cost-effective and attractive high-rise buildings it is necessary to have a holistic view. A holistic concept that takes into consideration the whole building process will yield time- and cost-efficient production while it will also make it possible to achieve better quality. The detail researches shows that embedding of the sheet metal profiles in the rigid insulation blocks will increase the buckling load of the stud and that the thickness of the plastering layer and the material properties of its substrate will affect the strains in the plastering layer and the moisture stored in it. Regarding the fire protection it could be stated that the Symphony outer wall construction protected with a double layer of gypsum board can maintain segregation of the fire up to 60 min as long as the gypsum boards do not crumble. In the production of the pilot projected it could be stated that the fact that the whole building was designed by one homogenous team with information about all details, made it possible to foresee many problems. The production of elements even in the temporary experimental production facility proved to be fast and economic, even with untrained labour force and the elements could be prefabricated to a very high level with facades that are plastered before assembly. / QC 20101108

One of the major degradation problems in concrete structures is chloride initiated reinforcement corrosion resulting in cracked, spalled and delaminated concrete. Thesedamages are repaired for large amounts of money and because of high repair costs it is important to perform durable repairs. This thesis work has included interviews, laboratory and field studies in the area of concrete repairs. The interviews were held mainly with bridge engineers at the Swedish Road Administration and Banverket (the Swedish Railway Administration). The questions asked tothese people were about their experience in the field of concrete repairs. The objective withthe interview study was to collect knowledge and experience about concrete repair at these two governmental authorities. The main objective of the laboratory study was to investigate chloride transport in the transition zone between a chloride contaminated substrate concrete and an initially chloride free repair concrete by establishing chloride profiles. The second objective was to detect any reinforcement corrosion in relation to the transition zone. The reinforced laboratory specimens with premixed chlorides (1 or 4 wt % per cement) in the substrate concrete have been exposed during 13 years either outdoors or in a climate chamber with relative humidity of 80 %. The main results show that reinforcement corrosion occurred in and near the transition zone in local active areas with passive areas between, macrocell corrosion, and that the chlorides are transported from the contaminated substrate concrete into the repair concrete. Three different repaired concrete structures, one road bridge, one pedestrian bridge and one parking structure, were investigated in the field study. All three structures are treated with deicing agents in the winter time. The objective with the field study was to investigate if the same phenomenon can be observed as in the laboratory study. The main conclusions, from the investigation on drilled cores from each structure, are that chlorides in contaminated substrate concrete can be transported into a repair concrete and reinforcement corrosion may occur in the transition zone between the two different materials. The results are in accordance with the results in the laboratory study. It was also seen that a repair concrete with relative low w/cratio may reduce the ingress of external chlorides. Finally, the results in this thesis indicate that there is a risk for reinforcement corrosion in the vicinity of the transition zone between repair concrete and a substrate concrete which must be considered in concrete repair work. For example the chloride content around a repair must not exceed a certain level when a repair is performed. The chloride transport into the repair concrete can be useful to transport chlorides and reduce the content of chlorides in the substrate concrete. The advantages with this are that the amount of removed contaminated substrate concrete can be minimized and the risk for corrosion in the substrate concrete is lower. If the repair concrete is reinforced with conventional black steel there may on the other hand be a risk for corrosion in the repair concrete instead if high levels of chlorides are transported. Also external exposure of chlorides must be considered for the risk of corrosion in the repair material. Further research is needed about when different corrosion mechanisms and chloride diffusion mechanisms occur in reinforced concrete repairs. The experience from the used analyzing methods in the laboratory investigations are possible to use in coming research projects in the field of concrete repair. The next step after this thesis work should be in order to increase the understanding of the repaired concrete system including the important compatibility issues, the author believes that the most fruitful way consists of further laboratory investigations, field studies and optimisation of the repair material. / QC 20101129

Water repellent agents, today mainly consisting of alkylalkoxysilanes, are often used on concrete to prolong the service life of the structure. This is accomplished by protecting the reinforcement bars from chlorides or by changing the moisture content inside. When the concrete is treated with a water repellent agent the properties of the surface layer turn from hydrophilic to hydrophobic and thereby water droplets are stopped from entering, still allowing water vapour to pass through. This property change can reduce chloride ingression and stop heavy rain from penetrating through the surface layer. This thesis presents results concerning how the moisture transport and fixation in the surface layer of the concrete is affected by a water repellent treatment. It also presents an investigation in which the effective penetration depth and the factors that influence it are studied. The methods used covers uni-dimensional transport of moisture using the so called cup method, measurements on moisture fixation using climate boxes with saturated salt solutions, penetration depth by cracking samples and spraying water on them, and field tests in a harsh tunnel environment. The moisture diffusion coefficient for a water repellent treated concrete is close to constant and not nearly as dependent on the relative humidity (RH) as for untreated concrete. Unlike untreated concrete, where capillary suction plays an important role for the moisture transport at high RH, the vapour transport is the dominant transport mechanism even at high RH for water repellent treated concrete. The moisture fixation is affected by a water repellent treatment and the effect is clearest at high moisture levels. There is, however, a certain amount of moisture present in a concrete treated with a water repellent agent. It can also be seen that the main reason for this is that the capillary porosity is affected by the treatment to a relatively high degree while the gel porosity to a large extent remains unaffected. The three most important factors for the penetration of any water repellent agent into concrete is time, porosity and degree of saturation. An empirical equation is derived that gives an idea on how much these factors affect the efficient penetration depth of the water repellent agent. Measures prolonging the service life of a concrete structure will lead to savings of natural resources and thus both economical and environmental savings for the community. The aim with the PhD-project is to develop explanation models to the promising results that have been obtained from the empirical research during the last decade and by doing this also create a better knowledge about when and how to apply a water repellent agent in order to benefit as much as possible from the product. The results presented in this Lisenciate thesis will be used as input in these models in the planned second phase of this project. / QC 20101117

Travel time estimation is an integral part of transportation management. The use of advanced technologies in collecting travel time information has been a major concern to transportation engineers and system operators who rely on such data to improve safety and emergency response of transportation facilities. GPS and Bluetooth are two of the available technologies which are efficient and cost effective in collecting travel time data. This study focuses on the accuracy analysis of them. This thesis begins with a review of the theory of Intelligent Transportation System (ITS) instruments. Then it illustrates the methods of travel time collection in three techniques, License Plate, Global Positioning System (GPS) and Bluetooth. Third, it outlines the method of processing of the data and the statistical method to compare the accuracy of GPS and Bluetooth. Last, it presents the results and analyzes the accuracy of two technologies.

No description available.

Human activity is the primary cause of climate change, particularly through the emission of greenhouse gases. The construction industry is one of the sectors that significantly contributes to the increasing amount of greenhouse gases in the atmosphere, and sustainable building materials can be part of the solution to this problem. This report analyzes the climate impact and cost of constructing building envelopes using materials of hemp and cellular glass compared to conventional ones from a life cycle perspective. The study includes a case study of a single-family house Hällebol. The focus of the study is the life cycle analysis of the production stage (A1-A3) and the end of life stage (C1-C4). The study demonstrates that building envelopes of hemp and cellular glass contribute to a lower level of climate impact compared to those made from conventional building materials. It also indicates that building envelopes of hemp and cellular glass can be more expensive alternatives than conventional ones, but the cost may vary depending on the specific conventional materials chosen. Furthermore, the study highlights the significant role of biogenic carbon storage in hemp cultivation in reducing overall climate impact. The rapid growth characteristics of hemp enable it to absorb substantial amounts of carbon dioxide through photosynthesis during the growth phase. If carbon storage is included in the assessment, the climate impact of climate barriers decreases significantly. The choice of materials in a climate barrier should be based on prioritized aspects in the specific context and the trade-off between climate impact and cost considerations.

In the dimensioning of a structural element, it is the structural engineer’s responsibilityto choose the type of concrete to be used by the given circumstances. However, theinfluence of external factors like the client or the contractor could affect the decision.But ultimately the decision comes down to the structural engineer. The approach ofstructural engineers in choosing concrete varies across individuals and companies, thereis no standardized method.The purpose of this study is to develop an effective and clear method for structuralengineers in selecting concrete and to discuss its potential impacts. This study is aqualitative case study with an initial survey. Data collection methods used in this studyinclude questionnaires, document analysis and interviews.In this study a flowchart was developed to make the process of selecting concrete clearand effective. The flowchart also includes climate-improved concrete as an optionproviding the structural engineers with the opportunity to propose both conventionalconcrete and climate-improved concrete using the same method.The study finds that the structural engineers use different methods in selecting concretewhich creates ambiguity regarding the correct choice. After applying the flowchart, thestructural engineers found it to be a clear method that was well visualized. Discussionsabout a standardized approach similar to the flowchart in selecting concrete wasdiscussed and its effects were seen as a good approach to increase insurance and clarityin selecting concrete. Additional discussions in the study regarding climate-improvedconcrete indicate a significant lack of knowledge among the structural engineers andthe need for improvement in the upcoming years.

No description available.

Vid uppförandet av träkonstruktioner är knutpunkter en del som de läggs mycket tid, pengar och resurser på. En knutpunktslösning kan utformas på flera olika sätt och är en kritisk del under flera skeden i ett projekt, hela vägen från anbud till montering. Martinsons Byggsystem AB (hädanefter ”Martinsons”) har genom åren arbetat fram olika typer av knutpunktslösningar och för att ständigt utvecklas och förbättras har de gett i uppgift att utreda och uppdatera lösningar mellan pelare och balk i limträstommar. Målsättningen med detta arbete har varit att utveckla knutpunktslösningar mellan pelare och balk i limträstommar för att sedan jämföra de mot varandra samt befintliga lösningar utifrån ett antal aspekter. Exempel på aspekter som jämfördes är tillverkning, kapacitet, projektering, montering, ekonomi och miljö. Detta har utförts i förstahand med hjälp av beräkningar i Excel och ritningar i AutoCAD. De knutpunktslösningar som har utretts är utanpåliggande stål- och trälaskar, trälaskslösningen inkluderar även en krysskruvning 45˚ genom skarven mellan pelare och balk. Det har uppförts ett dimensioneringsstöd i Excel för att kunna kontrollera kapaciteter och sammanställa egenskaper för olika utformningar och varianter av förband. I stödet kommer en utomstående person med kunskaper inom konstruktion kunna ange värden på laster och dimensioner som verkar och gäller för en anslutning. Dessa värden kommer resultera i att en cell vid förbanden visar grönt eller rött beroende på om de har godkända eller icke godkända kapaciteter och utformningar utifrån kontrollerna som stödet utför. I stödet ingår även en jämförelsetabell där egenskaper för de olika förbanden jämförs mot varandra. Denna information kommer en konstruktör kunna ha som grund vid valet av knutpunktslösning i ett projekt. Exempel på egenskaper som anges är materialåtgång, materialkostnad och miljöpåverkan. Slutsatsen som dragits är att metoden som använts har resulterat i en arbetsmetod som gör det möjligt att välja den mest optimala knutpunktslösningen för specifika projekt. Det är numera möjligt för konstruktörer på Martinsons att enkelt kontrollera kapaciteter och egenskaper för olika förband. Hen kommet att kunna jämföra lösningarna med varandra för att välja ut det bäst lämpade förbandet för just den anslutningen.

In Sweden, more buildings are being built today than ever before, while awareness of the consequences this has for the climate has increased. On January 1, 2022, a law came into effect to introduce climate declarations for new constructions. This is one step towards becoming a country that will have net zero emissions by 2045. To further develop the law, Boverket has developed a proposal to introduce limit values in climate declarations, which will apply from 2027. The introduction of limits will affect the construction industry as the future buildings will need to be built differently than they are today to meet the requirements.  This project aims to contribute knowledge in sustainability to reduce emissions in the construction industry. Furthermore, to provide suggestions for changes in a building's construction to meet the future limits. The building in this project is to symbolize a typical apartment building in Sweden. It has been modeled in the software Revit and then been exported to the Carbon Cost Compass software, where different examples of the building have been created, with differences in material choices. This while maintaining the average thermal transmittance, Um, as to not affect the building's insulation capacity. The result of the climatic action in the original building was 396.1 kg CO2e/m2BTA according to the requirements for 2027, in comparison with the limit value which was calculated to be 257-294 kg CO2e/m2BTA. Four different versions of the building were created with suggestions for changes in the construction, to meet the limit values. The version of the building with the lowest emission is the one referred to as "Minimum", with a climate action of 160.1 CO2e/m2BTA.  In May 2023, Boverket released an updated proposal regarding the expansion of climate declaration laws. The proposal presents initial threshold values for various building types, including apartment buildings. The suggested limit of 375 kg CO2e/m2BTA is planned to be implemented in 2025, with subsequent reductions every five years starting from 2030. This proposed number differs from the findings of this study. The variation could be attributed to the intention of initially avoiding overly strict regulations, allowing companies a reasonable opportunity to transition their production towards more sustainable construction practices. In conclusion, it is apparent that the use of wood as a building material will need to increase progressively. Alternatively, new methods for manufacturing other climate-friendly materials must be developed. / I Sverige byggs det idag mer än vad det någonsin gjorts tidigare, samtidigt som vetskapen om vilka konsekvenser detta har för klimatet blivit större. Den 1 januari 2022 trädde lagen i kraft om att införa klimatdeklarationer för nybyggnationer i Sverige. Detta är ett steg på vägen mot ett land som ska ha netto noll utsläpp 2045. För att vidareutveckla lagen har Boverket tagit fram ett förslag om att införa gränsvärden i klimatdeklarationer, som ska börja gälla 2027.   Införandet av gränsvärden kommer påverka byggbranschen då framtidens byggnader behöver byggas annorlunda än vad de görs idag, för att kunna möta klimatkraven. Detta arbete syftar till att bidra med kunskap inom hållbarhet, för att på sikt få ner utsläppen i byggbranschen. Vidare att ge förslag på förändringar i en byggnads konstruktion för att klara Boverkets framtida gränsvärden. Byggnaden i arbetet ska symbolisera ett typiskt flerbostadshus i Sverige, som modellerats upp i programvaran Revit. Denna har sedan exporterats till programvaran Carbon Cost Compass, där olika varianter av byggnaden har skapats, med skillnader i materialval. Detta har gjorts med bibehållen genomsnittlig värmegenomgångskoefficient i byggnaden, Um, för att inte påverka byggnadens isoleringsförmåga.   Resultatet av klimatberäkningen i det ursprungliga flerbostadshuset blev 396,1 kg CO2e/m2BTA enligt kraven för 2027, i jämförelse med gränsvärdet som beräknades ligga på 257–294 kg CO2e/m2BTA. Det skapades fyra olika versioner av byggnaden där förslag av förändringar i konstruktionen presenterades för att byggnaden skulle klara gränsvärdena. Den version av byggnad som hade minst utsläpp är den som i rapporten kallas för ’’Minimum’’, med ett klimatutsläpp på 160,1 CO2e/m2BTA. I maj 2023 kom Boverket ut med ett uppdaterat förslag på hur de ska vidareutveckla lagen om klimatdeklarationer. I förslaget framgår preliminära gränsvärden för olika byggnadstyper , däribland flerbostadshus. Gränsvärdet på 375 kg Co2e/m2BTA föreslås träda i kraft 2025 och därefter skärpas vart femte år med start 2030. Denna siffra skiljer sig från resultatet i detta arbete. Det skulle kunna bero på att lagskärpningen inte ska vara för strikt till en början, för att företag ska ha en god chans att ställa om sin produktion mot mer hållbara byggnader.   Slutsatsen är att materialen i en byggnad kommer behöva bytas ut mer och mer mot trä. Alternativt skapa nya sätt att tillverka andra material mer klimatsmart.