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Localization modelling with inner softening band finite elementsTano, Robert January 1997 (has links)
<p>Godkänd; 1997; 20070418 (ysko)</p>
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Avvattning : Fallstudie av väg 818 / Drainage : Case study of road 818Boström Sandin, Ante January 2020 (has links)
I den här rapporten kommer jag undersöka ifall den nya vägen 818 mellan Kilvo och Mukkavaara byggts enligt Trafikverkets standard gällande avvattning. Att inte säkerställa en god avvattning av vägen och på så sätt riskera att få vatten i vägkroppen kan vara helt avgörande för vägens livslängd. I de här arbetet så har jag sammanställt information om vägen och den tekniska beskrivningen som Trafikverket har skrivit och ifall Tyréns ritningar följer deras dokument. Enligt de kontrollberäkningar jag har gjort och kontrollerat dokumenten så följer alla diken och trummor de givna dimensioner som Trafikverket har satt och säkerställer att vägen ska klara den dimensionerade livslängden.
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Steel fibre corrosion in cracks : durability of sprayed concreteNordström, Erik January 2000 (has links)
Steel fibre reinforced sprayed concrete is common practice for permanent linings in underground construction. Today there is a demand on "expected technical service life" of 120 years. Thin steel fibres could be expected to discontinue carrying load fast with a decrease of fibre diameter caused by corrosion, especially in cracks. The thesis contains results from inspections on existing sprayed concrete structures and a literature review on corrosion of steel fibres in cracked concrete. To study the mechanisms ruling inititation and propagation of corrosion both field exposure tests and accelerated laboratory exposure tests with cracked steel fibre reinforced sprayed concrete have been performed. Parameters tested are type of spraying method, exposure environment, fibre length, usage of accelerators, crack width and time of exposure. A discussion on how the influence of corrosion on load bearing capacity should be considered in a service-life model is also presented. / Godkänd; 2000; 20070317 (ysko)
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Are we ready? : Swedish road operators readiness for automated vehiclesLarsson, Alva January 2021 (has links)
The European Union as well as Governments all around the world,including the Swedish Government, are putting a lot of time, money andeffort into facilitating the implementation of Automated Vehicles (AVs).The majority of these efforts tend to focus on either the technicalaspects, action plans or the legal scope. However, little attention isbeing drawn to the practical implications of these efforts. Hence, this thesis investigates the road operators’ willingness to act and their readiness in regards to data and information provision for AVs, as well as how the readiness can be improved. In particular, focus is geared towards the three largest road operators in Sweden: the city of Stockholm, the city of Gothenburg and the Swedish Transport Administration. The primary segments of data consists of information gathered through semi-structured in-depth interviews and benchmarking against international road operators. The results show a gap between the official visions of being at the forefront in automated mobility, and the actual practical implementations of these visions in the road operator organisation's. The author assigns this gap to a lack of incitements, decision-making,and monetary assets. Moreover, the findings suggest a correlationbetween the approach towards automated mobility within the organisationsand the actual level of readiness. This correlation is intensifiedduring the second data collection, when benchmarking international road operators against the Swedish. Further, the author underlines theimportance of managing this gap in order to achieve the strong coordination needed to reach the set up goals. The paper conclusively suggests, by comparing how road operators work with such matters in theNetherlands, Norway and Finland, how to overcome such obstacles.
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Klimatkalkyl, en konceptstudieStark, Elsa January 2020 (has links)
Klimatkalkylmodellen används i infrastrukturprojekt för både väg- och järnväg och tillhandahålls av Trafikverket. Verktyget är online baserat och uppdateras en gång per år. Hur vida en klimatkalkyl ska genomföras eller inte i projekten förhandlas fram i avtalen som skrivs mellan Trafikverket och AFRY. Klimatkalkylen resulterar i en sammanställning av samtliga typåtgärder och byggdelar som används och deras utsläpp beräknat i koldioxidekvivalenter. Utöver detta summeras även den totala användningen av bland annat asfalt med bitumen och diesel. Den totala sammanställningen presenteras i både koldioxidekvivalenter och energiförbrukning som presenteras i gigajoule. Med hjälp av denna sammanställning önskas ett verktyg tas fram för att underlätta uträkningar i klimatprojekt för att minska klimatutsläppen. Verktyget ska underlätta för konsulterna i sitt arbete att ta fram exempelåtgärder för att minska utsläppen ifrån projektet. Rapporten tar upp den konceptstudie som gjorts och tar fram exempel på hur framtagandet hur ett sådant verktyg kan se ut och rekommenderar AFRY att fortsätta med arbetet att ta fram detta.
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Laboratory Seismic Testing of Asphalt ConcreteGudmarsson, Anders January 2012 (has links)
Nondestructive laboratory seismic testing to characterize the complex modulus and Poisson’s ratio of asphalt concrete is presented in this thesis. These material properties are directly related to pavement quality and the dynamic Young’s modulus is used in thickness design of pavements. Existing standard laboratory methods to measure the complex modulus are expensive, time consuming, not truly nondestructive and cannot be directly linked to nondestructive field measurements. This link is important to enable future quality control and quality assurance of pavements based on the dynamic modulus.Therefore, there is a need for a more detailed and accurate laboratory test method that is faster, more economic and can increase the understanding and knowledge of the behavior of asphalt concrete. Furthermore, it should be able to be linked to nondestructive field measurements for improved quality control and quality assurance of pavements. Seismic testing can be performed by using ultrasonic measurements, where the speed of sound propagating through a material with known dimensions is measured. Seismic testing can also be used to measure the resonance frequencies of an object. Due to any excitation, a solid resonates when the frequency of the applied force matches the natural frequencies of the object. In this thesis, resonance frequency measurements have been performed at several different temperatures by applying a load impulse to a specimen while measuring its dynamic response. The measured resonance frequencies and the measured frequency response functions have been used to evaluate the complex modulus and Poisson’s ratio of asphalt concrete specimens. Master curves describing the complex modulus as a function of temperature and loading frequency have been determined through these measurements.The proposed seismic method includes measurements that are significantly faster, easier to perform, less expensive and more repeatable than the conventional test methods. However, the material properties are characterized at a higher frequency range compared to the standard laboratory methods, and for lower strain levels (~10-7) compared to the strain levels caused by the traffic in the pavement materials. Importantly, the laboratory seismic test method can be linked together with nondestructive field measurements of pavements due to that the material is subjected to approximately the same loading frequency and strain level in both the field and laboratory measurements. This allows for a future nondestructive quality control and quality assurance of new and old pavement constructions. / <p>QC 20121120</p>
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On investigation of stripping propensity of bituminous mixturesBagampadde, Umaru January 2004 (has links)
In this study, an experimental programme was designed toestablish a relationship between bituminous mixture constituentmaterial properties and their propensity to moisture induceddamage in form of stripping. Six bitumen types (3 from Ugandaand 3 from Sweden) with presumably varying characteristics wereevaluated basing on rheology and chemistry. Eleven aggregateswere used in this study. Seven were sourced from activequarries in Uganda and four were from Sweden. Bitumen rheology was established basing on penetration,softening point, viscosity, ductility and visco-elasticparameters obtained from dynamic mechanical analysis. Bitumenchemistry was studied using Fourier Transform InfraredSpectroscopy, Gel Permeation Chromatography (GPC) and ThinLayer Chromatography (TLC). Bituminous mixtures were reconstituted from the bitumen andaggregate combinations basing on the Swedish mix designprocedure ROAD 94 using dense graded mixtures with 16mm maximumaggregate size (AG16). Mixture sensitivity to moisture wasevaluated basing on Swedish FAS 446-98 specifications closelyrelated to the modified Lottman procedure. The investigation was done in two phases namely, (a) theeffect of aggregate properties on mixture moisture sensitivityand (b) the of cross effects of bitumen and aggregates onmixture moisture sensitivity. The results reveal chemical compositional differences inbitumens that would be considered similar basing on classicalrheological properties like penetration and viscosity. Resultsof dynamic mechanical analysis show that binders have similarvisco-elastic response around 0oC. This could be a potentialphenomenon to serve as a grading scheme for bitumen as is thecase with penetration and viscosity grading systems. The results from phase I of the study show that presence ofCa-feldspars and ferromagnesian minerals in aggregates largelyrelates to improved resistance of mixtures to moisture damage.In addition, mixtures from aggregates with high concentrationsof acid insolubles (SiO2 and Al2O3) are sensitive to moisturedamage. The results of phase II of this study show that the choiceof aggregate type is the dominant factor affecting moisturesensitivity of the resulting mixtures. Bitumen type seems notto be an important factor in determining moisture sensitivityof bituminous mixtures. Aggregates with Ca-feldspars andferromagnesian minerals seemed to be the most resistant tomoisture damage irrespective of the bitumen type. Assessment of moisture sensitivity basing on absolutestiffness values of water treated mixtures seems not to bereliable. Results from this study show that mixtures withsimilar wet resilient moduli had varying tensile strengthratios, hence varying moisture sensitivity tendencies. Modulusof resilience ratio (MRR) and tensile strength ratio (TSR)parameters show similar trends in comparing moisturesensitivity of different mixtures. However, MRR values aregenerally lower than TSR values for the same mixtures.
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Vägskador av tung trafik : Upplåtande av vägnätet för 74-tons lastbilar. / Road damage due to heavy vehicles. : Introducing 74-ton trucks on the road system.Lundberg, Kevin, Gonzales, Elkin January 2016 (has links)
No description available.
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Pavement Response to Moving LoadsKhavassefat, Parisa January 2014 (has links)
The response of flexible pavements at vehicle-road interaction has been studied in this thesis. A quasi-static and a dynamic framework for analysing the pavement structure under moving load has been developed. Both frameworks are general, robust and computationally efficient. The quasi-static procedure is based on superposition principle and is computationally favourable, as it requires only reduced incremental problem to be solved numerically. Using the developed framework the effect of vehicle configuration and traffic characteristics on the damage induced in pavements is investigated numerically. It is shown that the developed numerical model provides a more accurate explanation of different distress modes. Moreover the conventional analysis and design methods with layered linear elastic behaviour assumption for asphalt layer are unable to capture several important aspects of pavement response. In the dynamic analysis approach the pavement roughness and vehicle suspension system is linked to a dynamic pavement model in order to account for the dynamic effects at vehicle-road interaction on pavement response. A finite element method is relied upon in order to establish the response function for a linear viscoelastic pavement structure with dynamic effects taken into account. The computational procedure developed is applied to evaluate the effect of the pavement surface roughness on the pavement structure response to truck traffic loading. Stress field parameters governing fracture initiation in asphalt layers are reported for two measured road roughness profiles. It is shown that the dynamic effects at vehicle-road interaction may have a profound influence on the stresses induced in flexible pavements; therefore these effects need to be taken into account for accurate prediction of the road performance in the field. / <p>QC 20140516</p>
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Möjligheter och utmaningar för ökad användning av miljövänlig betong i anläggningsprojektHamid Garakani, Sasha, Karlsson, Måns January 2022 (has links)
Reducing carbon dioxide emissions is one of the biggest and most important tasks in modern times in the world. Sweden has a national climate target that net emissions of carbon dioxide should be zero by 2045. Construction projects in Sweden account for approximately 8% of total emissions, where concrete is one of the building components with the largest emissions. Concrete is one of the world's most widely used building materials and accounts for approximately 43 percent of emissions in the construction industry. In order to reduce emissions and for Sweden to reach the climate goals by 2045, a change in the current use of concrete is required. One measure could be for the construction industry to use more environmentally friendly concrete with less carbon dioxide emissions. Increased use of environmentally friendly concrete can contribute to a change in the construction industry for a reduction in carbon dioxide emissions. The purpose of the study is that the work will investigate what challenges there are in implementing environmentally friendly concrete and that the study will propose what measures are required to promote the use of environmentally friendly concrete for contractors in construction projects. The aim of the study is to develop challenges and potential measures to promote the implementation of environmentally friendly concrete in the construction industry for contractors. In order to be able to answer the purpose, the following research questions have formed the basis of the study: 1. What are the challenges for construction contractors to increase the use of environmentally friendly concrete in construction projects? 2. What measures are required to promote increased use of environmentally friendly concrete in future construction projects? The study is based on an interview study with respondents who work with the implementation of environmentally friendly concrete in some way. The interview study consisted of nine respondents whose roles were project manager, client and concrete researcher. That the study is based on an interview study that has interviewed people with different roles in the construction industry was to broaden the study to get more perspectives on challenges and measures with the use of environmentally friendly concrete. The challenges that have emerged in the study of implementing environmentally friendly concrete in construction projects are limited regulations, time aspect, dependence on key people, internal communication, uncertainty in deliveries and rumours in the construction industry. Based on the challenges, four different measures have been presented to promote the use of environmentally friendly concrete. The four measures are that time planning should take place earlier in the process, focus more clearly on feedback on environmental aspects, more organization-driven projects on environmental choice and to introduce a budget for innovation solutions in the construction industry. Environmentally friendly concrete is constantly being developed and the study must be relevant even when the development of environmentally friendly concrete has progressed further. The regulations in the construction industry affect all the challenges and measures presented in the study. In order to be able to approach net zero emissions from concrete in the construction industry, updated regulations are required that call for change and innovations. / concrete, implementing, increase, challenges
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