Digitala Vetenskapliga Arkivet

Change search
Refine search result
1234567 1 - 50 of 6032
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1.
    Aagah, Orod
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Aryannejad, Siavash
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Dynamic analysis of soil-steel composite railway bridges: FE-modeling in Plaxis2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    A soil-steel composite bridge is a structure comprised of corrugated steel plates, which are joined with bolted connections, enclosed in friction soil material on both sides and on the top. The surrounding friction soil material, or backfill, is applied in sequential steps, each step involving compaction of the soil, which is a necessity for the construction to accumulate the required bearing capacity. Soil-steel composite bridges are an attractive option as compared with other more customary bridge types, owing to the lower construction time and building cost involved. This is particularly true in cases where gaps in the form of minor watercourses, roads or railways must be bridged.

    The objective of this master thesis is the modelling of an existing soil-steel composite railway bridge in Märsta, Sweden with the finite element software Plaxis. A 3D model is created and calibrated for crown deflection against measurement data collected by the Division of Structural Engineering and Bridges of the Royal Institute of Technology (KTH) in Stockholm, Sweden.

    Once the 3D model is calibrated for deflection, two 2D models with different properties are created in much the same way. In model 1, the full axle load is used and the soil stiffness varied, and in model 2 the soil stiffness acquired in the 3D model is used and the external load varied. The results are compared to measurement data. In 2D model 1 an efficient width of 1,46 m for the soil stiffness is used in combination with the full axle load, and in 2D model 2 an efficient width of 2,85 m is used for the external load, in combination with the soil stiffness acquired in the 3D model.

    Aside from this, parametric studies are performed in order to analyse the effect of certain input parameters upon output results, and in order to analyse influence line lengths.

    Recreating the accelerations and stresses in the existing bridge using finite element models is complicated, and the results reflect this. Below are shown the discrepancies between model results and measurement data for the pipe crown. The scatter in the measurement data has not been taken into consideration for this; these specific numbers are valid only for one particular train passage.

    For crown deflection, the 3D model shows a discrepancy of 4%, 2D model 1 5% and 2D model 2 8% compared with measurement data. For crown acceleration, in the same order, the discrepancy with measurements is 1%, 71% and 21% for maximum acceleration, and 46%, 35% and 28% for minimum acceleration. For maximum crown tensile stress, the discrepancy is 95%, 263% and 13%. For maximum crown compressive stress, the discrepancy is 70%, 16% and 46%.

    Download full text (pdf)
    fulltext
  • 2. Aalhuizen, Christoffer
    Potential of V2G in a Rural Low-Voltage Grid on Gotland for Voltage and Power Capacity Control2019Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Swedish transportation sector needs to undergo major changes in order to achieve the established goals for climate and environment. The largest change is the replacement of fossil-fuelled vehicles to vehicles propelled by renewable energy sources, such as biofuels and electricity. To account for an increase in local electric power consumption, the electric power infrastructure of Sweden needs to adapt through expansion and reconstruction of the electric power grid. However, changes in infrastructure are usually expensive. It is therefore suitable to also examine alternative solutions, which could potentially be more cost efficient. One of these solutions are vehicle-to-grid (V2G), where electric vehicles acts as local electric power control and provides auxiliary services to the electric power grid. This thesis is a case study of a part of a low-voltage electric power grid on Gotland, with the goal of analysing the potential of V2G in the investigated area. The study focused on utilizing V2G for balancing electric power consumption and generation, and for adjusting voltage levels. Simulations of the area were executed in PSS®E for three different cases; one high-load case, low-load case and average-load case. It was found that by utilizing V2G a ramp up of electric power during mornings was delayed by approximately one hour, making the electric power grid potentially more compatible with photovoltaics (PV). However, the overall effects from V2G was fairly low. This outcome can partly be explained by the assumptions made in the report, and also due to some odd behaviour of the system model. 

    Download full text (pdf)
    fulltext
  • 3.
    Abbas, Nada
    et al.
    Linnaeus University, Faculty of Technology, Department of Informatics.
    Kans, Mirka
    Linnaeus University, Faculty of Technology, Department of Mechanical Engineering. Chalmers University of Technology, Sweden.
    Information Needs of Gravel Road Stakeholders2022In: Infrastructures, E-ISSN 2412-3811, Vol. 7, no 12, article id 166Article in journal (Refereed)
    Abstract [en]

    Within any ecosystem, information sharing is essential. In this paper, the Swedish gravel road ecosystem is studied, where information plays a crucial role for the effective management of operations and maintenance. However, efficient information sharing is not enabled due to the lack of appropriate information systems. For addressing this issue, this paper intends to elicit information needs of gravel road stakeholders to support the design of a cloud-based information system. The main purpose is to explore the information needs of stakeholders within the Swedish gravel road ecosystem. Data were collected through in-depth semi-structured interviews with 11 participants representing key stakeholders in the ecosystem. Template analysis was used for analyzing the interview results. The major findings were a set of information needs covering road identification and condition, weather conditions, accessibility and traffic, maintenance policy, and sensor data. The results form a comprehensive information model for the further development of a cloud-based gravel road management system that would contribute to increased traffic safety and comfort, lower maintenance and management costs, and better decision-making abilities.

    Download full text (pdf)
    fulltext
  • 4.
    Abbasiverki, Roghayeh
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Analysis of underground concrete pipelines subjected to seismic high-frequency loads2016Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Buried pipelines are tubular structures that are used for transportation of important liquid materials and gas in order to provide safety for human life. During an earthquake, imposed loads from soil deformations on concrete pipelines may cause severe damages, possibly causing disturbance in vital systems, such as cooling of nuclear power facilities. The high level of safety has caused a demand for reliable seismic analyses, also for structures built in the regions that have not traditionally been considered as highly seismically active. The focus in this study is on areas with seismic and geological conditions corresponding to those in Sweden and Northern Europe. Earthquakes in Sweden for regions with hard rock dominated by high-frequency ground vibrations, Propagation of such high-frequency waves through the rock mass and soil medium affect underground structures such as pipelines.

    The aim of this project is investigating parameters that affect response of buried pipelines due to high-frequency seismic excitations. The main focus of the study is on reinforced concrete pipelines. Steel pipelines are also studied for comparison purposes. The effects of water mass, burial depth, soil layer thickness and non-uniform ground thickness caused by inclined bedrock are studied. The results are compared to those obtained for low-frequency earthquakes and the relationship between strong ground motion parameters and pipelines response is investigated. It is shown that, especially for high frequency earthquake excitations, non-uniform ground thickness due to inclined bedrock significantly increase stresses in the pipelines. For the conditions studied, it is clear that high-frequency seismic excitation is less likely to cause damage to buried concrete pipelines. However, the main conclusion is that seismic analysis is motivated also for pipelines in high-frequency earthquake areas since local variation in the ground conditions can have a significant effect on the safety.

    Download full text (pdf)
    fulltext
  • 5.
    Abbasiverki, Roghayeh
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Analysis of buried reinforced concrete pipelines subjected to seismic waves2014Conference paper (Refereed)
  • 6.
    Abbasiverki, Roghayeh
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Seismic response of large diameter buried concrete pipelines subjected to high frequency earthquake excitations2020In: Int. J. Structural Engineering, ISSN 1758-7328, Vol. 10, no 4, p. 307-329Article in journal (Refereed)
    Abstract [en]

    Buried pipelines are tubular structures that cross large areas with different geological conditions. During an earthquake, imposed loads from soil deformations on pipelines may cause drastic damages. In this study two dimensional finite element models of pipelines and surrounding soils are usedfor simulation of seismic waves that propagate from the bedrock through thesoil. The models describe both longitudinal and transverse cross-sections ofpipelines and the soil-pipe interaction is described as a nonlinear behaviour.The effects of uniform ground with different burial depth and soil layer thickness, soil stiffness and non-uniform ground on the seismic response of reinforced concrete pipelines is studied. Two earthquakes, with high and low frequency contents, are employed for the dynamic analysis. The results show asignificant effect on the response due to non-uniform ground caused by inclined bedrock, especially for high frequency earthquake excitations.

  • 7.
    Abbasiverki, Roghayeh
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Larsson, Stefan
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Soil and Rock Mechanics.
    Seismic response of buried concrete pipelines subjected to highfrequency earthquakesIn: Geotechnical and Geological Engineering, ISSN 0960-3182, E-ISSN 1573-1529Article in journal (Refereed)
    Abstract [en]

    Buried pipelines are tubular structures that cross large areas with different geological conditions. During an earthquake, imposed loads from soil deformations on concrete pipelines may cause severe damages. In this study, the use of two-dimensional finite element models of pipelines and surrounding soil for simulation of seismic waves that propagate from the bedrock through the soil are demonstrated. The models describe both longitudinal and transverse cross-sections of pipelines and the soil-pipe interaction is modelled as a nonlinear behaviour. The effects of uniform ground with different burial depths, soil layer thickness, soil stiffness and bedrock geometry on the seismic response of reinforced concrete pipelines is studied. Two earthquakes, with high and low frequency contents, are employed for the dynamic analysis. The results show that there is a much smaller risk of damage from high-frequency earthquakes, but that there is a significant effect on the response due to possible irregular ground with inclined bedrock.

  • 8.
    Abbasiverki, Roghayeh
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Malm, Richard
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Analysis of shallowly buried reinforced concrete pipelines subjected to earthquake loads2014In: Nordic Concrete Research, ISSN 0800-6377, no 51, p. 111-130Article in journal (Refereed)
    Abstract [en]

    Buried reinforced concrete pipelines are widelyused in e.g. water and wastewater systems. Failure of these infrastructures mayresult in drastic effects and recently they have been brought into focus asvital components in safety systems for nuclear power installations. The highlevel of safety has here lead to a demand for reliable earthquake risk analyses.In this paper, methods are compared and the use of seismic design loadsdemonstrated. FE analysis in 2D of soil-pipe interaction under seismic wavepropagation is performed. The performance of concrete pipes subjected toseismic waves with different frequency content is evaluated with respect todifferent soil condition but also water mass effect.

  • 9.
    Abbasiverki, Roghayeh
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Malm, Richard
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Ansell, Anders
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Nordström, Erik
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Nonlinear Behaviour of Concrete Buttress Dams under High-Frequency Excitations Taking into Account Topographical Amplifications2021In: Shock and Vibration, ISSN 1070-9622, E-ISSN 1875-9203, Vol. 2021, p. 1-22Article in journal (Refereed)
    Abstract [en]

    Concrete buttress dams could potentially be susceptible to high-frequency vibrations, especially in the cross-stream direction, due to their slender design. Previous studies have mainly focused on low-frequency vibrations in stream direction using a simplified foundation model with the massless method, which does not consider topographic amplifications. This paper therefore investigates the nonlinear behaviour of concrete buttress dams subjected to high-frequency excitations, considering cross-stream vibrations. For comparison, the effect of low-frequency excitations is also investigated. The influence of the irregular topography of the foundation surface on the amplification of seismic waves at the foundation surface and thus in the dam is considered by a rigorous method based on the domain-reduction method using the direct finite element method. The sensitivity of the calculated response of the dam to the free-field modelling approach is investigated by comparing the result with analyses using an analytical method based on one-dimensional wave propagation theory and a massless approach. Available deconvolution software is based on the one-dimensional shear wave propagation to transform the earthquake motion from the foundation surface to the corresponding input motion at depth. Here, a new deconvolution method for both shear and pressure wave propagation is developed based on an iterative time-domain procedure using a one-dimensional finite element column. The examples presented showed that topographic amplifications of high-frequency excitations have a significant impact on the response of this type of dam. Cross-stream vibrations reduced the safety of the dam due to the opening of the joints and the increasing stresses. The foundation modelling approach had a significant impact on the calculated response of the dam. The massless method produced unreliable results, especially for high-frequency excitations. The free-field modelling with the analytical method led to unreliable joint openings. It is therefore recommended to use an accurate approach for foundation modelling, especially in cases where nonlinearity is considered.

  • 10. Abd-Alla, E. S. M .
    et al.
    Moriyoshi, A.
    Partl, Manfred
    EMPA, Swiss Federal Laboratories for Materials Testing and Research.
    Takahashi, K.
    Kondo, T.
    Tomoto, T.
    New wheel tracking test to analyze movements of aggregates in multi-layered asphalt specimens2006In: Journal of the Japan Petroleum Institute, ISSN 1346-8804, E-ISSN 1349-273X, Vol. 49, no 5, p. 274-279Article in journal (Refereed)
    Abstract [en]

    This paper describes a new wheel tracking test for analyzing movements of aggregates in mixtures. The test device is conducted using as examples four-layered specimens taken from two Swiss national motorways, where severe rutting (G section) and longitudinal cracking (H section) were observed. This test method was developed by Moriyoshi. Tests can be carried out under temperature distributions similar to field situation. Two-dimensional movements and strains between aggregates for four-layered specimens due to the moving wheel loads were analyzed by right angle for direction of wheel pass. For this purpose, the cross section of the slabs with a width of 30 cm was divided optically into 5 vertical subsections. The transverse permanent surface deformations, the area changes in the transversal subsections as well as the maximum deformation of the surface and layer-interface through the centerline of the applied wheel load were determined. Strain distributions between aggregates in mixtures at high temperature (45 degrees C) under 600 passes were also measured by photo analysis. Test results show consolidation of the asphalt mixtures and material flow on the surface near the wheel load. The results also demonstrate that the aggregates (size of aggregate: 2 mm or larger) in each mixture move mainly in vertical direction. Large strains (40% or larger) between aggregates at summer condition were measured in the surface mixture near wheel track after 600 passes.

  • 11.
    Abdeljaber, Osama
    et al.
    Qatar University, Qatar.
    Younis, Adel
    Qatar University, Qatar.
    Avci, Onur
    Qatar University, Qatar.
    Catbas, Necati
    University of Central Florida, USA.
    Gul, Mustafa
    University of Central Florida, USA.
    Celik, Ozan
    University of Central Florida, USA.
    Zhang, Haiyang
    University of Alberta, USA.
    Dynamic Testing of a Laboratory Stadium Structure2016In: Geotechnical and Structural Engineering Congress 2016, American Society of Civil Engineers (ASCE), 2016, p. 1719-1728Conference paper (Other academic)
    Abstract [en]

    Studies with large physical models are a vital link between the theoretical work and field applications provided that these models are designed to represent real structures where various types and levels of uncertainties can be incorporated. While comprehensive analytical and laboratory joint studies are ongoing at Qatar University, University of Central Florida and University of Alberta, this paper presents the initial findings of dynamic testing at Qatar University. A laboratory stadium structure (grandstand simulator) has been constructed at Qatar University. Capable of housing thirty spectators, Qatar University grandstand simulator is arguably the largest laboratory stadium in the world. The structure is designed in a way that several different structural configurations can be tested in laboratory conditions to enable researchers to test newly developed damage detection algorithms. The study presented in this paper covers the finite element modeling and modal testing of the test structure.

  • 12.
    Abdelmomen Samir Abdeljawad, Najmadin
    Mälardalen University, School of Business, Society and Engineering.
    Fastighetsförvaltningsbolags definition av BIM som objektbaserad informationsbärare: En fallstudie av BIM användning vid Nya Karolinska Solna2020Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of the study was to explore how property management companies view of Building Information Modeling (BIM) as a working method in property management process, and to explore the companies efforts at BIM in terms of the level of detail on BIM object implementation in property management. The study includes both companies that have and do not have contributions in BIM. The exploration was aimed at two companies and their varying ways of working to inform the needs of BIM in property management. The purpose of the study was also to give a clear picture of how BIM tools should be defined in the management process. The work was used of qualitative methods to answer the questions first consisted of a literature review, interviews and case study. The case study was about BIM implementation in New Karolinska Solna. The result showed that the definition of BIM in property management companies is not clear yet. The companies have intended to use BIM, but they are not there yet, there should be a type of requirements list that works with planning and production and benefit from using BIM in the property management. According to respondents, most of the common reasons why BIM was not used were because the approach of the tool. There is no proper structure or common working method of how the tool would be applied. Many literature sources including respondents claimed that BIM seemed good and have a good potential to be the future work process. BIM leads to improved work environment, improved sustainability development, good marketing, increased quality in work, time savings, and improved project management. As a suggestion as to how BIM could be implemented, it can be described in a few steps, which is status analysis, identify the benefits of BIM, start implementing on a smaller scale, follow up continuously, improve and expand the work and last but not least Integrate information. The conclusions that can be drawn from the results and literature study were that BIM can improve the quality management of the properties, but it is important to find a reasonable level of BIM implementation as well as a suitable detail level of BIM-model.

    Download full text (pdf)
    Examensarbete Abdelmomen Najmadin
  • 13.
    Abdi, Adel
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Lind, Hans
    KTH, School of Architecture and the Built Environment (ABE), Real Estate and Construction Management.
    Birgisson, Björn
    KTH, School of Architecture and the Built Environment (ABE), Transport Science.
    Designing appropriate contracts for achieving efficient winter road and railway maintenance with high performance quality: A survey of the state of practice in Sweden2014In: International Journal of Quality and Service Sciences, ISSN 1756-669X, E-ISSN 1756-6703, Vol. 6, no 4, p. 399-415Article in journal (Refereed)
    Abstract [en]

    Purpose - For a long time, the winter maintenance of the Swedish road and railway network had been performed in-house by Swedish Transport Administration, Swedish local authorities i.e. municipalities and Stockholm public transport. During the last 15 years the winter operation and maintenance of these state infrastructures have been performed by public procurement and contracting from independent contractors, where in practice the lowest price is the dominating selection criteria. The aim of this paper is to investigate and identify how these contracts are designed and how satisfied the parties are with the contract and the quality of the performed work during the winter and point our directions for improvement. Design/methodology/approach - The study was conducted by a literature review and followed by semi-structured interviews and electronic questionnaire. Findings - The results of the study which are based on the interviews and the online questionnaire show that there is widespread dissatisfaction with the contracts among both clients and contractors. Practical implications - The article prepares a basis showing how a contract affects the quality of the performed winter road and railway maintenance services. Originality/value - The findings lead to a number of suggestions about how to improve the contracts, e.g. having a separate winter maintenance contract to increase the quality of performed winter maintenance measures, a more partnering-like structure where consultations and adjustment can be made during the contract period. A partnering structure also makes it less important to get all the details right in the contract.

  • 14.
    Abdi Yussuf, Yusuf
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    Jalal Ibrahim, Zand
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Technology and Design.
    FRP:s användning inom brokonstruktioner2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    At present, most bridges in Sweden are made with concrete or steel. These bridges are often associated with high costs, which often depend on maintenance and repair. FRP, which stands for Fiber Reinforced Polymer, is a relatively new material in load-bearing structures but is a well- established material in the context of reinforcement. In Europe and in particular the Netherlands, there are several bridges built in FRP. But due to a lack of norms and regulations to lean against, there is rarely any kind of FRP bridge construction in Sweden. The aim of this thesis is to examine existing norms and study how the material FRP is used in the reinforcement and construction of bridges. Furthermore, this thesis also aims to investigate the properties of FRP as building material and compare it with conventional materials such as steel and concrete. FRP, also called fiber-composite, is a composite material that can be assembled in several different ways. Through various materials that are combined and different manufacturing processes used, one can thus provide individual designs for the material. The benefits of FRP are many, but generally it has good strength, good durability while having a low weight. This results in that within bridge construction, it gives the structure a reduced self-weight, which in turn facilitates a variety of things. This thesis shows that FRP materials have advantageous properties and in some situations can be more favorable to use than steel or concrete. However, as previously pointed out, there are no specific Eurocodes for this material. However we are sure that the introduction of a new Eurocode and encouragement from authorities will undoubtedly increase the use of FRP in bridge construction.

    Download full text (pdf)
    fulltext
  • 15.
    Abdulameer, Hasanain
    et al.
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Chamoun, Kristian
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    BIM i små och medelstora anläggningsföretag.2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose: The purpose of this bachelor thesis is to improve the usage of BIM in facility projects.

    Method: The methods used for this bachelor thesis are qualitative interviews and literature studies.

    Findings: Free programs will be available for usage where models can be opened, viewed, examined and studied. The small and medium-sized facility companies will not be forced to use resources to cope with the requirements of Trafikverket.

    Implications: Consequences are that the small and medium-sized civil engineering companies understand and follow the requirements.

    • Using more 3D models to gain more experience and skills in the subject.

    • Attend the Trafikverkets industry days when opportunities arise, the authors believe that it was very instructive.

    • Engage in more BIM projects.

    • Older projects where the drawings are in 2D is converted into 3D.

     

    Limitations: How BIM is used during the management process will not be covered.

    Keywords: Productivity, resource, competence, experience, BIM.

    Download full text (pdf)
    fulltext
  • 16.
    Abdulkader, Ammar
    Umeå University, Faculty of Science and Technology, Department of Applied Physics and Electronics.
    Förseningar i byggprojektering och hur de kan förebyggas2023Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Idag är förseningar inom byggbranschen vanliga och orsakar problem och konsekvenser i byggprojekt. När ett projekt blir försenat uppstår extra kostnader för projektägaren, entreprenören eller båda parter. Med andra ord innebär förseningar ekonomiska förluster och skapar en stressig arbetsmiljö för alla inblandade aktörer och projektmedlemmar. I detta examensarbete identifieras betydande risker som kan orsaka förseningar i projekteringsfasen av byggprocessen, samt presenteras lösningar för att förebygga dem.

    Byggprocessen består av fyra faser: förstudie, projektering, produktion och överlämning. Projekteringsfasen är ett av de viktigaste stegen i byggprocessen och har stor betydelse för att förebygga förseningar. I denna fas utformas och ritas byggnader, och bygghandlingar tas fram med konstruktionsritningar, tekniska lösningar och beskrivningar upprättas för att styra hela byggprocessen.

    Detta arbete fokuserar på förseningar i själva projekteringsfasen och dess påverkan på hela projektet, samt hur de kan förebyggas. Arbetet består av en teoretisk och en praktisk del. Syftet med arbetet är att undersöka orsakerna till förseningar inom projekteringsfasen och att hantera dem på bästa sätt genom att utveckla riskhanteringen. Orsakerna kan vara ofullständig information, förändringar i projektspecifikationer och tekniska problem. Teorin bygger på litteratur om projektering i byggprocessen för att ge en bred kunskapsbas om projektering innan den praktiska delen genomförs. Den praktiska delen baseras på intervjuer med erfarna projektledare inom projektering som har varit involverade i olika försenade projekteringsprocesser. Resultatet presenterar projektledarens svar angående orsakerna till förseningarna i de två projekten. I diskussionen jämförs och analyseras resultaten med teorin, vilket visar att sjukdomar och bristande kommunikation, tillsammans med andra risker, kan vara orsaker till förseningar i projekteringsfasen. Förbättringsförslag inkluderar att skapa en trygg och hälsosam arbetsmiljö som en viktig faktor för projektets framgång, genom att anlita ytterligare konsulter från andra företag vid arbetsbelastning och erbjuda avkopplande aktiviteter som exempelvis spa-besök när det behövs. Andra förslag innefattar att lägga extra tid på riskanalys för att identifiera potentiella problem samt att etablera en kommunikationsmetod för grupper, såsom en grupp på Messenger eller en annan applikation, där all information om projektet regelbundet delas.

    Download full text (pdf)
    fulltext
  • 17.
    Abdullah, Gamil M. S.
    et al.
    Department of Civil Engineering, College of Engineering, Najran University, Najran, Saudi Arabia.
    Chohan, Imran Mir
    Department of Mechanical Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Malaysia.
    Ali, Mohsin
    Graduate School of Urban Innovation, Department of Civil Engineering, Yokohama National University, Kanagawa, Japan.
    Bheel, Naraindas
    Department of Civil and Environmental Engineering, Universiti Teknologi PETRONAS, Bandar Seri Iskandar, Malaysia.
    Ahmad, Mahmood
    Institute of Energy Infrastructure, Universiti Tenaga Nasional, Kajang, Malaysia; Department of Civil Engineering, University of Engineering and Technology Peshawar (Bannu Campus), Bannu, Pakistan.
    Najeh, Taoufik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Operation, Maintenance and Acoustics.
    Gamil, Yaser
    Department of Civil Engineering, School of Engineering, Monash University Malaysia, Jalan Lagoon Selatan, Selangor, Malaysia.
    Almujibah, Hamad R.
    Department of Civil Engineering, College of Engineering, Taif University, Taif, Saudi Arabia.
    Effect of titanium dioxide as nanomaterials on mechanical and durability properties of rubberised concrete by applying RSM modelling and optimizations2024In: Frontiers in Materials, E-ISSN 2296-8016, Vol. 11, article id 1357094Article in journal (Refereed)
    Abstract [en]

    The use of rubber aggregates derived from discarded rubber tyres in concrete is a pioneering approach to replacing natural aggregate (NA) and promoting sustainable building practices. Recycled aggregate in concrete serves the dual purpose of alleviating the accumulation of discarded rubber tyres on the planet and providing a more sustainable alternative to decreasing natural aggregate. Due to fact that the crumb rubber (CR) decreases the strength when used in concrete, incorporating titanium dioxide (TiO2) as a nanomaterial to counteract the decrease in strength of crumb rubber concrete is a potential solution. Response Surface Methodology was developed to generate sixteen RUNs which contains different mix design by providing two input parameters like TiO2 at 1%, 1.5%, and 2% by cement weight and CR at 10%, 20%, and 30% as substitutions for volume of sand. These mixtures underwent testing for 28 days to evaluate their mechanical, deformation, and durability properties. Moreover, the compressive strength, tensile strength, flexural strength and elastic modulus were recorded by 51.40 MPa, 4.47 MPa, 5.91 MPa, and 40.15 GPa when 1.5% TiO2 and 10% CR were added in rubberised concrete after 28 days respectively. Furthermore, the incorporation of TiO2 led to reduced drying shrinkage and sorptivity in rubberized concrete, especially with increased TiO2 content. The study highlights that TiO2 inclusion refines pore size and densifies the interface between cement matrix and aggregate in hardened rubberized concrete. This transformative effect results in rubberized concrete demonstrating a commendable compressive strength comparable to normal concrete.

    Download full text (pdf)
    fulltext
  • 18.
    Abdulrahman, Keiwan
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Potrus, Fadi
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Numerical analysis and model updating of a steel-concrete composite bridge: Parametric study & Statistical evaluation2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the year 2006, only 10 years after the steel- concrete composite bridge, Vårby bridge was built, fatigue cracks were found during an inspection. To further investigate the reasons and the potential danger of the cracks, an investigation under the commission of the Swedish Transport Administration was issued in 2009. After the detection of fatigue cracks, several measurements were carried out in order to monitor the static behavior by the use of strain gauges at selected positions along the bridge. The measurements from the strain gauges monitoring the global behavior were then used to calibrate an finite element model.

     

    The present report is part of the research of understanding the behavior of steel-concrete composite bridges. Numerical analysis and model updating have been used in order to understand and determine how different parameters affects the strain range and the global behavior. The numerical analysis and parameter study were performed in the Finite Element software Abaqus and programming language Python. The outcome of the parameter study was then used to perform the model updating by the method of falsification in MATLAB.

     

    The results from the parameter study and the model updating showed that the measured strains could be reached with a wide range of parameter combinations. Even with unreasonable parameter values, the measured strains were obtained. To investigate the reason for this, a multiple linear regression analysis was performed which showed that the strain range is strongly correlated to the Young’s modulus of steel and concrete and also to the connector elasticity, which resembles the studs in the real bridge.

     

    Two different finite element models, with two completely different input parameter values, obtain the same strain range for the global behavior. It is therefore not certain to assume that a model is accurate and valid based on the fact that the predicted strain range from the finite element model is close to the measured strain range since the global behavior of a steel- concrete composite bridge can be modeled by many different sets of parameters.

    Download full text (pdf)
    Numerical analysis and model updating of a steel-concrete composite bridge
  • 19. Abed, Ahmed
    et al.
    Bizarro, Diana Eliza Godoi
    Neves, Luis
    Parry, Tony
    Keijzer, Elisabeth
    Kalman, Björn
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Carrion, Ana Jimenez Del Barco
    Lo Presti, Davide
    Mantalovas, Konstantinos
    Buttitta, Gabriella
    Airey, Gordon
    Uncertainty analysis of life cycle assessment of asphalt surfacings2024In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 25, no 2, p. 219-238Article in journal (Refereed)
    Abstract [en]

    The Life Cycle Assessment (LCA) of asphalt pavements are associated with significant uncertainty resulting from variability in the quantity and impact of individual components, the quality of data for each component, and variability of asphalt durability. This study presents a framework to quantify and incorporate the uncertainty of LCA and asphalt durability data into LCA of asphalt surfacings. The suggested framework includes: estimating the uncertainty of asphalt production processes by the pedigree matrix method, conducting a deterministic LCA, applying Monte Carlo Simulation (MCS) to estimate the probability density functions (PDFs) of the considered impacts using the uncertainty data, deterministic solution, and asphalt durability. This framework was applied to six asphalt mixtures; the results show that there is significant uncertainty in the processes that contribute to the environmental impacts. They also showed that considering asphalt durability and its uncertainty is critical and can significantly change the results and interpretation of LCA.

  • 20.
    Abrahamsson, Josef
    et al.
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Karlsson, Mikael
    Jönköping University, School of Engineering, JTH, Civil Engineering.
    Bullerbegränsande åtgärder för byggnation nära befintlig väg2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Purpose: When cities grow at a faster rate, new places are needed to build housing.The municipalities that are growing tends to choose build sites that previously wererejected due to noise pollution. There are requirements from the state that the noise maynot exceed certain values. The requirements originate from the fact that over twomillion swedes are exposed to noise daily. Noise can lead to health problems, in theform of sleep disorders and cardiovascular disease. To reduce health problems noiseinvestigations are made, where suggestions are made in how noise levels can bereduced. The purpose of the work is to provide the reader with knowledge of whichfactors influence noise investigations and the approach to the choice of noise reductionmeasures so that construction can be made closer to trafficked roads.

    Method: The methods used are literature studies, document analysis and interviews.The literature gathered consists of scientific articles. The documents consist of noiseinvestigations conducted by different companies all over Sweden. Persons to interviewwere chosen from the conductors of the noise investigations documents.

    Findings: To answer the report's purpose, three questions were raised. The firstquestion deals with noise-reducing technologies and which technologies are used today.The report found that there are several ways to reduce noise. In the following order, themost frequently used are: silent facade, noise screen, speed reduction, distance betweenhouse and roads, vegetation, road moving and quiet asphalt. The second question of thereport addresses the factors that influence the choice of noise reduction measure. Fromthe literature study, absorption, reflection and reduction were found to be importantfactors. In the document analysis, surroundings, traffic and speed emerged as importantfactors. In the interviews, aesthetics and price emerged as important in the choice ofwhich reducing action should be taken. The third question deals with the question ofhow construction can be made closer to the road. In the result it appears that all of thesolutions mentioned earlier have the ability to reduce noise, but how effective they areand how well they reduce noise varies from case to case. Surroundings and trafficvolume are of great importance.

    Implications: Making use of the technical solutions previously described, results in areduced noise level and there for construction near road can be made possible.Executing a noise investigation at an early stage means that later and more expensivechanges can be avoided, which means that construction can take place sooner. Thereport suggests therefore that noise issues should be considered early in projects. It isalso important to get a solution that everyone can accept.

    Limitations: The report's results are limited to a smaller selection of noiseinvestigations and interviews. More investigations and interviews could hadcontributed to a larger spectrum. The report does only consider noise outdoors and whatopportunities for noise reduction there are.

    Download full text (pdf)
    Bullerbegränsande åtgärder för byggnation nära befintlig väg
  • 21.
    Acar, Yalda
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Jingstål, Pontus
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Influence of the Non-linear Effects in the Design of Viscous Dampers for Bridge Cables2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this master thesis the performance of external viscous dampers attached to cables in cable-stayed bridges have been studied. A comparison has been performed between a linear and a non-linear cable model. The comparison was carried out for two bridge cables, one from the Dubrovnik Bridge and the other from the Normandie Bridge. The performance of the dampers have been measured in terms of maximum achieved damping ratio and minimum amplitude of vibration.

    The analysis was performed using the finite element method. The damping ratio was measured using both the half-power bandwidth method and by calculating the loss factor. The half-power bandwidth method can only be applied to a linear system. Therefore, the loss factor was evaluated for the linear model and compared to the results obtained using the half-power bandwidth method. From the comparison, it was concluded that the damping ratio evaluated using the loss factor was similar to the results obtained when using the half-power bandwidth method. However, when calculating the loss factor, it was of great importance that the resonance frequency of the system was accurately determined. The loss factor was then calculated for the non-linear model and compared to the results obtained for the linear model. Since the loss factor measures the energy dissipated in a system, it could be utilised for the non-linear model. When computing the strain energy for the non-linear model an approximate method was used to take into consideration the strain energy caused by the static deformation of the cable.

    From the comparison between the linear and non-linear cable models, it was concluded that the optimal damper coefficients obtained by both models are not significantly different. However, there is an uncertainty in the results due to the fact that an approximate method was used when calculating the strain energy for the nonlinear model. It was also observed that a very accurate evaluation of the system’s resonance frequency was needed to calculate the loss factor. It was also observed that the variation in amplitude of vibration for varying damper coefficient was small for all modes of vibration for the Dubrovnik Bridge Cable as well as for the first mode of vibration for the Normandie Bridge Cable. The difference in the results between the two bridge cables needs to be investigated further in order to get a better understanding of the results.

    Download full text (pdf)
    fulltext
  • 22. Acciona, S.A.
    C4R D 4.3.2 Demonstration of new monitoring techniques2017Report (Other academic)
    Abstract [en]

    This Deliverable D4.3.2 presents the results of the research carried out in task 4.3.4 of SP4 Advanced Monitoring - WP4.3 Implementation in new structures. The aim of this deliverable is to describe the specific design, installation process, testing protocol and test results from the monitoring system devised in previous tasks (and described in D4.3.1). Said system has been installed in the demonstrators for the new infrastructure concepts developed in SP1, which shall also be thoroughly described in the document.

    Download full text (pdf)
    C4R D 4.3.2 Demonstration of new monitoring techniques
  • 23.
    Adamsson, Mathias
    et al.
    Jönköping University, School of Engineering, JTH, Civil Engineering and Lighting Science.
    Petersson, Mikael
    Jönköping University, School of Engineering, JTH, Civil Engineering and Lighting Science.
    Aries, Myriam
    Jönköping University, School of Engineering, JTH, Civil Engineering and Lighting Science.
    A holistic approach for a natural light variation experience: a pilot study of a practical application for office lighting2019Conference paper (Refereed)
    Abstract [en]

    Lighting is crucial for vision and has important effects beyond vision, influencing a variety of physiological and behavioral processes. When designing lighting, visual aspects, effects beyond vision, and perception of the environment should be considered together in a holistic approach. As humans evolved under daylight, a lighting protocol, based on a room context and daylight characteristics, was developed and described. The lighting, with customized light levels, spectral composition and light distribution that changed dynamically to evoke a perception of daylight conditions, was realized using commercially available luminaires and a digital control system. The resulting lighting conditions are described by measurements.

  • 24. Adell, Anton
    Innovativ tätning av läckande dilatationsfogar i betongdammar: Bentonit: Metoder, Utvärdering och Fallstudie2022Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Most of Sweden’s concrete dams were built during the 1900’s. Therefore, they are starting to reach the estimated end of their life-cycle; 50-160 years. Some of these concrete dams are used for hydroelectric purposes. Hydroelectric power is one of Sweden’s primary source for electricity, which approximately makes for 45% of our total electric production. Hence, the need for reparation is increasing for further management and maintaining our electricity production in these concrete dams. Concrete dams are linked by expansion joints. These expansion joints help to reduce the stress, during swelling and shrinking, in the concrete caused by temperature variation. Due to the placement of these expansions joint, they become difficult to repair as well as ensuring the success of a reparation.

    Inside the expansion joint there are dimbands. The dimbands can be sealed with bitumen to help their water stopping abilities. For every expansion joint that is sealed with bitumen the estimated climate impact is 0,5 to 1,5 kg CO2-e per joint. If the dimbands, inside the expansion joint, or the surrounding concrete gets damaged or breaks the bitumen varnishes downstream. This generates for an increased environmental and climate impact, due to the need for new bitumen and steel to fill and seal the leak and oils being released into the surroundings. Therefore, it is also of interest to reduce the usage of bitumen or remove it completely from these dimbands. To minimize the complexity and reduce the usage of bitumen this thesis will evaluate a reparation method with bentonite pellets. The reparation method consists of a borehole, which is then backfilled, with bentonite pellets. There are two concrete dams in Sweden which have used this method. Therefore, this thesis work also aims to evaluate how this reparation will last, regarding time, against other options and future expectations regarding the replacement of bitumen.

    To begin, the bentonite pellets where first evaluated based on their swelling capabilities and moisture absorption. These attributes were tested by new methods, which are partly based on previous standards. These new methods for the material properties also allowed for long-term evaluation. To evaluate how the bentonite pellets would react over time they were placed in a temperature change cabinet. Five days in these cabinets, were assumed to, correspond to the Northern Swedish climate changes that takes place over a year.  The bentonite pellets were then evaluated by the new methods after 1,5 and 3 years. The results, for both swelling and moisture absorption, showed a difference depending on the bentonite type. The pure Na-bentonite moisture absorption has better absorption capabilities over time, compared to chemically produced Na-bentonite. The results from swelling shows that, regardless of bentonite type, they all induce worse swelling capabilities over time. Although, if they begin thawing cycles at a lower water content their swelling capabilities increases due to the bentonite experiencing exsiccation. 

    After the first experimental part, and this newly gathered material knowledge, a miniature version of a concrete dams’ expansion joint were built. The background to this was to research how many altitude meters (mVp) the bentonite pellets could withstand before collapse. Vattenfalls engineers built the testrigg, expansion joint, which primarily consisted of steel. A splintered concrete cube, with a predrilled hole in the middle, was then placed in this steel cartridge. The hole was then filled with bentonite pellets. To see the sequence of the material reaction during pressure tests the testrigg had a top of plexiglass. A manometer was then attached to the plexiglass. The manometer, and a consistent flow of water, allowed for the pressure to be monitored and regulated. When the sedimented bentonite pellets collapses the pressure drops. 

    Results from the pressure tests show a correlation between the bentonite pellets declared swelling pressure and the externally supplied water pressure. Depending on the inflow the bentonite pellets can withstand a pressure between 5 to 12 meters of water height – where the exact value is given by the time it is allowed to sediment. These values only consider the initial expansion of the material. Further research is required to evaluate how much water pressure the material can withstand over time.

    Based on the findings of this study one of the previously repaired concrete dams’ bentonite seal will collapse in due time, since the reparation exceeds 12 meters in height.

    Based on the information provided in this thesis it is difficult to decide whether a bentonite seal will be beneficial for the concrete structure. Further research is required to ensure the sustainability of using bentonite inside concrete structures.

    Download full text (pdf)
    fulltext
  • 25. Adell, Emeli
    et al.
    Evanth, Katarina
    Åström, Jonas
    Fotgängare och cyklister inom systemet för uppkopplade och samverkande transporter2016Report (Other academic)
    Abstract [sv]

    Rapporten är framtagen med ekonomiska bidrag från Trafikverkets Skyltfond. Ståndpunkter och slutsatser i rapporten reflekterar författaren och överensstämmer inte med nödvändighet med Trafikverkets ståndpunkter och slutsatser inom rapportens ämnesområden. Detta projekt är en förstudie inför mer omfattande studier i framtiden om hur ett uppkopplat och samverkande transportsystem kan integrera oskyddade trafikanter och hur det påverkar dem. Fokus har varit hur oskyddade trafikanter kan kopplas upp till systemet och vad trafiksäkerhetsnyttan är för dessa trafikanter. Trots stora forskningsframsteg har konsekvenser för oskyddade trafikanters trafiksäkerhet eller hur oskyddade trafikanter kan inkluderas i det uppkopplade transportsystemet inte undersökts i någon större utsträckning. Det finns flera studier som undersöker de positiva effekterna av samverkande transporter, men dessa är ofta avgränsade till motorfordonstrafik och trafikflöden. Helhetsperspektivet där alla trafikantgrupper ingår som samverkande komponenter i systemet saknas. Hittills ligger mycket fokus på den tekniska utvecklingen. Oskyddade trafikanter har hittills oftast setts som ”hinder” som ska undvikas genom teknikens hjälp. Få projekt inom ITS utgår från de oskyddade trafikanterna eller erbjuder tekniska lösningar för att hindra olyckor relaterade till dem. Det är viktigt att tillämpa ett systemtänkande vid utvecklingen av systemet redan initialt för att nå de bästa effekterna för alla trafikantgrupper. Denna studie har visat att det finns olika möjligheter att koppla upp fotgängare och cyklister i det uppkopplade och samverkande trafiksystemet. Det som verkar enklast och smidigast i dagsläget är att oskyddade trafikanter använder en app i sin smartphone. Att utrusta alla oskyddade trafikanter med en ny typ av sensor eller dosa är inte lika enkelt att genomföra. Och att bygga upp ett system där infrastrukturen och fordon detekterar de oskyddade trafikanterna utan att dessa själva ”behöver” någon utrustning verkar ligga längre i framtiden. Än viktigare att påpeka är att en sådan lösning verkar exkludera interaktion med eller mellan de oskyddade trafikanterna, vilket borde vara målsättningen för ett helt uppkopplat och samverkande transportsystem. Kunskapssammanställningen visar att de flesta experter bedömer att förbättrad trafiksäkerhet är en av de stora fördelarna med ett uppkopplat och samverkande transportsystem. I enkätstudien 2:3 som genomfördes inom detta projekt svarade flest respondenter att trafiksäkerhetsvinsten är den största fördelen med ett uppkopplat och samverkande transportsystem samt specifikt att ett sådant system skulle leda till ökad trafiksäkerhet för oskyddade trafikanter. Dock har det inte visats inom föreliggande studie exakt hur eller i vilken omfattning trafiksäkerheten kommer att förbättras för någon trafikantgrupp inklusive oskyddade trafikanter. För att kunna öka trafiksäkerheten för fotgängare och cyklister, måste hänsyn tas till psykologiska faktorer så som t ex beteendekompensation, d v s när trafikanter ändrar sitt beteende för att uppväga för en ändring i trafiksituationen. Även hur ny teknik i form av visuella, auditiva och taktila signaler påverkar trafikanter bör undersökas närmare. Hur nya system påverkar trafikantbeteenden är en nyckelfaktor när det gäller vilka effekter de nya systemen kommer få. En bättre förståelse av detta är nödvändigt både i utveckling och i utvärdering av systemen.

    Download full text (pdf)
    Fotgängare och cyklister inom systemet för uppkopplade och samverkande transporter
  • 26. Adell, Emeli
    et al.
    Ljungberg, Caroline
    Börefelt, Alexander
    Rosqvist, Lena Smifelt
    Systemeffekter av införande av HCT på väg: Befintlig kunskap och intressenters inställning2014Report (Other (popular science, discussion, etc.))
    Abstract [sv]

    Debatten kring ett införande av HCT (High Capacity Transport) går het både i Sverige och runt om i Europa. En av de punkter som det diskuteras mycket kring är vilka effekter en sådan reform skulle få på trafiksystemet som helhet, dvs. vilka systemeffekter en sådan förändring skulle föra med sig. En av de känsligaste frågorna är om att HCT skulle flytta gods från järnväg till väg. Om detta är en riktig bild eller inte finns det många åsikter om. Både bland olika delar av industrin, bland politiker och bland olika forskargrupper - nationellt och internationellt. Denna studie syftar till att sammanställa den dokumenterade kunskap som finns kring systemeffekter av ett införande av HCT på väg, samt att beskriva olika intressenters inställning till ett införande på väg, inklusive vad denna inställning grundas på. Studien behandlar systemeffekterna av ett införande av HCT, d.v.s. effekter på trafiksystemet på grund av införande av HCT. Fokus ligger på överflyttningseffekter. Med HCT menar vi i denna rapport ekipage som är tyngre och/eller längre än det som är tillåtet idag. Studien inkluderar alla olika typer av HCT på väg, och begränsar sig därmed inte enbart till den förändring som i dagsläget är aktuellt i Sverige (vikthöjning från 60 ton till 74 ton). Eftersom de flesta europeiska länder idag tillåter 40 ton och 18,75 meter, är detta utgångspunkten för mycket av den europeiska litteraturen som ingår i litteraturstudien. Detta bör hållas i minnet vid tolkning av resultaten. Projektet har utförts i två delstudier: 1. Systemeffekter av ett införande av HCT på väg – en sammanställning av befintlig kunskap (litteraturstudie) 2. Intressenters inställning till införande av HCT på väg – en intervjustudie Litteratursammanställningen visar att kunskapen kring systemeffekter av ett införande av HCT på många sätt är bristfällig. Den samlade bild som ges av befintlig litteratur är att effektiviseringar är att vänta per tonkm, vilket t.ex. avspeglar sig i lägre transportkostnader. Oenighet råder dock om de totala effekterna vilket bottnar i olika bedömningar av överflyttningseffekten (inkl. en eventuell ökad efterfrågan på transporter). Detta gör att det inte är möjligt att dra några tydliga slutsatser kring systemeffekterna vid ett införande av HCT utifrån den litteratur som finns idag. Detta sammanfattar också relativt bra inställningarna bland intressenter i området. De olika inställningarna kring ett införande av HCT på väg beror i huvudsak på olika bedömningar av storleken på överflyttning av transporter från järnväg/sjöfart till väg och hur man bedömmer att efterfrågan av transporter skulle påverkas om man inför HCT på väg. Överflyttning från järnväg och sjöfart är den springande punkten till varför det finns olika slutsatser kring systemeffekter av ett införande av HCT. Intressenter och litteratur med en negativ inställning till ett införande av HCT har generellt sett ett längre tidsperspektiv än de som är positiva och neutrala/kluvna. De som är negativa till ett införande av HCT utgår i större utsträckning från riktningen man vill att samhället ska utvecklas i, och lägger mindre betydelse vid de närliggande vinster man uppfattar att ett införande av HCT kan föra med sig.

    Download full text (pdf)
    Systemeffekter av införande av HCT på väg: Befintlig kunskap och intressenters inställning
  • 27.
    Adler, Jeremy
    et al.
    The Wenner-Gren Institute, Stockholm University, Sweden.
    Bergholm, Fredrik
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Pagakis, Stamatis N.
    Biomedical Research Foundation Academy of Athens, Athens, Greece.
    Parmryd, Ingela
    The Wenner-Gren Institute, Stockholm University, Sweden.
    Noise and colocalization in fluorescence microscopy: solving a problem2008In: Microscopy and Microanalysis, ISSN 1431-9276, E-ISSN 1435-8115, Vol. 22, no 5Article in journal (Refereed)
  • 28.
    Adolphson, Marcus
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Transport planning.
    Impact on urban form by the localization of railway stations: Evidence from Sweden2019In: Cities, ISSN 0264-2751, E-ISSN 1873-6084, Vol. 95, article id 102362Article in journal (Refereed)
    Abstract [en]

    Since the 1990s a number of new railway stations have been established in Sweden on new or rerouted lines, while other stations have been reconstructed at their original locations. Some stations were located in urban surroundings, others in semi-urban or peripheral locations depending on the trade of between regional speed, and local urban circumstances. The urban form consequences depending on station localisation of these transport infrastructure investments are nonetheless unknown. In order to provide a basis for future planning, this research aims to provide knowledge on urban form consequences of relocating railway stations. 13 stations were selected in a case study. Changes in urban densities from 1993 to 2013 were analysed by a combination of kernel techniques and estimation of monocentric density models. Stations within an urban and semi-urban environments show strong agglomeration tendencies. Within peripheral environments, the urban development was unclear or even negative. In an urban environment, the location of the station still attracted more urban resources compared to the location of the urban density centre. These findings should be understood in the light of a market-oriented socio-economic context since 1990th influencing the planning system and the development of urban form.

  • 29.
    Afridi, Amjad
    et al.
    Skellefteå Municipality, Sweden; Department of Building Materials, KTH Royal Institute of Technology, Stockholm, Sweden.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure.
    Management of municipal street network in Sweden: results from a national survey2024In: Sammanställning av referat från Transportforum 2024 / [ed] Fredrik Hellman; Mattias Haraldsson, Linköping: Statens väg- och transportforskningsinstitut , 2024, p. 395-396Conference paper (Other academic)
    Abstract [en]

    Management of street networks is different from state roads due to its multifunctional role in society. This requires timely maintenance of the street network to improve socioeconomic development. Municipalities in Sweden are responsible for the management of about 42000 km of street network in their jurisdiction. Maintenance budget and resources vary from municipality to municipality depending on their network size, geographical location, and population density. 

    A questionnaire was sent to all 290 municipalities across the country to investigate the street network and pavement management practices at the municipal level. An in-depth interview of 14 municipalities took place afterwards. A total of 51% of responses were officially received to highlight the frequently and infrequently occurring pavement distresses and their causes. Furthermore, the study highlights the maintenance approaches and allocation of budget to manage the street network. Lastly, the study highlights the factors which need to be addressed to improve street network management.   

    Visual assessment of pavements is common and the use of pavement management system (PMS) is not only limited but also lacks pavement performance prediction models. Common pavement distresses are excessive formation of potholes, surface unevenness and alligator distress among the municipalities. Frequent causes of distress include the ageing of the street network, heavy vehicles, patching and high traffic flow. Furthermore, cold climate and population density are important factors in the degradation process. Allocation of maintenance and reconstruction budget is relatively high in municipalities located in the north. Densely populated municipalities have higher taxpayers’ contributions to maintenance and reconstruction. Other major issues are limited resources and maintenance of budget, which adversely affect the maintenance backlog and the choice of maintenance alternatives, ultimately the decision-making. This restricts the use of preventive maintenance among the municipalities. 

    Municipalities are required to improve the frequency and quality of pavement data collection, enhance the sophistication of PMS by using pavement deterioration models, and increase the maintenance budget and resources. An insight into the capabilities of municipalities would help in long-term strategic planning and effective utilisation of the maintenance budget to improve the street network across the country.  

  • 30.
    Afridi, Muhammad Amjad
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Skellefteå Municipality, Strömsörgatan 15, 93134 Skellefteå, Sweden.
    Municipal street pavement maintenance and management practices in Sweden2024Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    A well-functioning street network is pivotal in the socio-economic development of a region. Street networks not only facilitate the movement of people and goods but also allocate space for utility services. Maintaining the street network in good condition and meeting the sustainability targets necessitate implementing optimal street maintenance strategies, leading to an efficient utilization of taxpayers' money. 

    The objectives of this Licentiate thesis are to analyse pavement management practices and challenges faced by Swedish municipalities, specifically focusing on asphalt concrete (AC) pavements within street networks. Additionally, it seeks to integrate a sustainability tool into pavement maintenance to select maintenance measures that contribute to sustainability goals at the municipal street network management level. Furthermore, the study aims to enhance municipal-level pavement maintenance approaches through the implementation of machine learning (ML) models within a pavement management system (PMS). 

    Within this context, three individual studies were conducted—two case studies and a survey involving Swedish municipalities. One case study explores sustainability framework application, whereas the other investigates the utilization of ML models in municipal AC pavement maintenance. The survey investigates the practices and challenges faced by municipal street network administrations in AC pavement maintenance.

    The sustainability framework SUNRA (Sustainability National Road Administrations) was adopted by the Swedish Transport Administration (STA) with a primary emphasis on promoting sustainability in pavement management on state-level roads. In this study, the framework has been tested, applied and further streamlined to be applicable for setting sustainability targets and monitoring sustainability performances at the project level within both the STA and municipal contexts. The aim was to simplify the framework so it is appropriate for investment, re-investments, maintenance and operation projects and also to enhance its applicability for various users. The study additionally explored how the framework could contribute to sustainability, identified the drivers and barriers for its application, and examined its applicability and adaptability to projects of varying complexities. The results indicate that the framework can be readily utilized and adapted for investment, reinvestment, maintenance, and operational pavement projects during the planning stage. Additionally, it is also suitable for small municipal establishments, construction or reconstruction of residential areas, and regular maintenance.

    A web-based questionnaire survey was disseminated to municipalities across the country to gather first-hand insights into the current practices and challenges associated with street maintenance at the municipal level in Sweden. Survey responses were received from 147 of the 290 (51%) municipalities nationwide. The study reveals that predominant pavement distress encompasses potholes, surface unevenness, and alligator cracking, with the most prevalent causes being pavement ageing, heavy traffic, and patches. Likewise, cold climate and population density serve as influential factors contributing to pavement deterioration. The automated survey methods for collecting pavement condition data, such as road surface scanning vehicles and application of commercial PMS, are very limited. On the contrary, the windshield method, a subjective approach for pavement condition assessment, is widely adopted among municipalities utilizing PMS. The allocation of the budget for maintenance, rehabilitation and reconstruction is higher in the northern regions of the country, as well as in densely populated municipalities.

    Manually collected pavement condition data for the years 2014 and 2018 were acquired from Skellefteå municipality to assess the performance of ML models in comparison to the observed pavement condition index (PCI) of the street network. In this context, the supervised ML models Linear Regression (LR), Random Forest (RF), and Neural Network (NN) were employed in conjunction with several variable combinations. The RF model, utilizing paired variables of pavement age (A) and pavement distresses (D) data, consistently demonstrated higher accuracy compared to the other models for residential streets. However, RF models constructed with paired variables of A and traffic (T) consistently outperformed other models in the context of non-residential streets. The significance of input variables fluctuates based on the model's complexity and the pavement performance objective. Nonetheless,  variable A consistently emerges as the predominant factor for predicting PCI in both residential and non-residential street models. 

    Further evaluation of the models and simplification of the SUNRA framework to enhance pavement performance and sustainability are recommended. 

    Download (pdf)
    Kappan_utan artiklar
  • 31.
    Afridi, Muhammad Amjad
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Skellefteå Municipality, Strömsörgatan 15, 93134 Skellefteå, Sweden.
    Erlingsson, Sigurdur
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Swedish National Road and Transport Research Institute, 58195 Linköping, Sweden.
    Englund, Cristofer ()
    Center for Applied Intelligent Systems Research (CAISR), Halmstad University, 30118 Halmstad, Sweden.
    Predicting pavement condition using an ML approach: A municipal case studyIn: Journal of Transportation Engineering, Part B: Pavements, ISSN 2573-5438Article in journal (Other academic)
  • 32.
    Afridi, Muhammad Amjad
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Skellefteå Municipal, Skellefteå, Sweden..
    Erlingsson, Sigurdur
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Building Materials. Swedish Natl Rd & Transport Res Inst VTI, Linköping, Sweden.;Univ Iceland, Fac Civil & Environm Engn, Reykjavik, Iceland..
    Sjogren, Leif
    Swedish Natl Rd & Transport Res Inst VTI, Linköping, Sweden..
    Municipal street maintenance challenges and management practices in Sweden2023In: Frontiers in Built Environment, E-ISSN 2297-3362, Vol. 9, article id 1205235Article in journal (Refereed)
    Abstract [en]

    The municipal street network acts as a multifunctional asset by providing people, vehicles and public services with a well-functioning infrastructure. To keep it in good condition, optimal maintenance measures are required which would result in an efficient use of taxpayers' money. This paper investigates the street network deterioration processes and the management practices that the municipal administrations have applied in Sweden. The study is based on a survey with Swedish municipalities using questionnaires and complementary interviews. The answers provide insight into a wide range of common pavement distresses and deterioration factors, along with pavement management practices. The study identifies that potholes, surface unevenness and alligator cracking are the most cited challenges, while pavement ageing, heavy traffic and patches are the most noted causes. Similarly, the cold climate and population density are influential factors in pavement deterioration. Allocation of the maintenance and rehabilitation and reconstruction budget is higher in the northern part of the country as well as in densely populated municipalities. Condition data collection and use of commercial Pavement Management Systems (PMS) are limited. Addressing the challenges effectively may be possible through the enhancement of the budget, feasible/clear guidelines from municipal councils/politicians, and reducing the gap between street network administrations and utility service providers.

  • 33.
    Afridi, Muhammad Amjad
    et al.
    KTH, Sverige.
    Erlingsson, Sigurdur
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology. KTH, Sverige.
    Sjögren, Leif
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Municipal street maintenance challenges and management practices in Sweden2023In: Frontiers in Built Environment, E-ISSN 2297-3362, Vol. 9, article id 1205235Article in journal (Refereed)
    Abstract [en]

    The municipal street network acts as a multifunctional asset by providing people, vehicles and public services with a well-functioning infrastructure. To keep it in good condition, optimal maintenance measures are required which would result in an efficient use of taxpayers' money. This paper investigates the street network deterioration processes and the management practices that the municipal administrations have applied in Sweden. The study is based on a survey with Swedish municipalities using questionnaires and complementary interviews. The answers provide insight into a wide range of common pavement distresses and deterioration factors, along with pavement management practices. The study identifies that potholes, surface unevenness and alligator cracking are the most cited challenges, while pavement ageing, heavy traffic and patches are the most noted causes. Similarly, the cold climate and population density are influential factors in pavement deterioration. Allocation of the maintenance and rehabilitation and reconstruction budget is higher in the northern part of the country as well as in densely populated municipalities. Condition data collection and use of commercial Pavement Management Systems (PMS) are limited. Addressing the challenges effectively may be possible through the enhancement of the budget, feasible/clear guidelines from municipal councils/politicians, and reducing the gap between street network administrations and utility service providers.

    Download full text (pdf)
    fulltext
  • 34.
    Agrawal, Dhiraj
    et al.
    Department of Civil Engineering, Yeshwantrao Chavan College of Engineering, Hingna Road, Wanadongri, Nagpur, 441110, India.
    Waghe, Uday
    Department of Civil Engineering, Yeshwantrao Chavan College of Engineering, Hingna Road, Wanadongri, Nagpur, 441110, India.
    Ansari, Khalid
    Department of Civil Engineering, Yeshwantrao Chavan College of Engineering, Hingna Road, Wanadongri, Nagpur, 441110, India.
    Amran, Mugahed
    Department of Civil Engineering, College of Engineering, Prince Sattam Bin Abdulaziz University, 11942, Alkharj, Saudi Arabia; Department of Civil Engineering, Faculty of Engineering and IT, Amran University, 9677, Amran, Yemen.
    Gamil, Yaser
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Department of Civil Eng., School of Eng., Monash University Malaysia, Jalan Lagoon Selatan, 47500, Sunway, Selangor, Malaysia.
    Alluqmani, Ayed E.
    Department of Civil Engineering, Islamic University of Madinah, Madinah, 41411, Saudi Arabia.
    Thakare, Nitin
    Department of Civil Engineering, G. H. Raisoni Institute of Engineering and Technology, Nagpur, 441110, India.
    Optimization of eco-friendly concrete with recycled coarse aggregates and rubber particles as sustainable industrial byproducts for construction practices2024In: Heliyon, E-ISSN 2405-8440, Vol. 10, no 4, article id e25923Article in journal (Refereed)
    Abstract [en]

    In this technology era, sustainable construction practices have become quite imperative. The exploration of alternative materials to reduce the environmental footprint is of paramount importance. This research paper delves into an exhaustive investigation concerning the utilization of recycled coarse aggregates (RCA) and rubber particles (RP) in concrete. It contributes to the growing body of knowledge aimed at fostering sustainable development in the construction industry by reducing waste, promoting recycling, and mitigating the environmental footprint of building materials. The objective of the study is to evaluate the potential benefits and limitations associated with incorporating these materials, thereby providing a sustainable alternative to conventional concrete. In this research, construction and demolition waste were recycled and used as RCA as a fractional switch of natural coarse aggregate (NCA) from 0% to 100%, with an increment of 20% replacement of NCA in concrete. The RP received from discarded tires generated as automobile industry waste were used as a volumetric fractional substitution of sand in concrete from 0% to 20%, with a 5% increment. No pre-treatment for RCA and RP was carried out before their utilization in concrete. A total of 26 mixes, including control concrete without NCA and RP, with a design strength of 40 MPa, were prepared and tested. Concrete mixes were examined for workability, density, mechanical, and durability properties. It was found that the concrete with 60% RCA and 10% RP showed satisfactory results in evaluation with the strength parameters of control concrete, as the compressive strength obtained for this concrete mix is 40.18 MPa, similar to the control mix. The optimization for RCA and RP was conducted using Response Surface Methodology (RSM). The major concern observed was a rise in water absorption with an increase in the percentage replacement of NCA and natural sand by RCA and RP. Findings from the investigation illustrate a promising prospect for the use of RCA and RP in concrete applications, displaying competent mechanical properties and enhanced durability under certain conditions, offering a viable option for environmentally friendly construction practices. However, the research also sheds light on some constraints and challenges, such as the variability in the quality of RCA and the necessity for meticulous quality control to ensure the reliability and consistency of the end product. It is discerned that further refinement in processing techniques and quality assurance measures is pivotal for mainstream adoption of RCA and RP in concrete construction.

    Download full text (pdf)
    fulltext
  • 35.
    Agredo Chavez, Angelica Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Gonzalez, Jaime
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Andersson, Kasper
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Leidzen, Jon
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Andersson, Erik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Petersson, Mats
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Häggström, Jens
    Swedish Traffic Administration, Luleå, Sweden.
    Cracking and Fatigue of Heavy Loaded Prestressed Concrete Bridge in Sweden2022In: IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures - Report, International Association for Bridge and Structural Engineering / [ed] František Wald; Pavel Ryjáček, Zürich: International Association for Bridge and Structural Engineering, 2022, p. 792-799Conference paper (Refereed)
    Abstract [en]

    A prestressed concrete bridge was built in 1963 with BBRV cables. It has three spans and a total length of 134.8 m. Due to mining activities the bridge was loaded with trucks with a total weight of 90 ton during 2012-2014 and from 2019. Crack development has been monitored manually and from 2020 with strain gauges and LVDTs.

    Cracks normally vary between 0.1 to 0.3 mm in width and grow in length with time. In November 2020 some of the strain gauges on the concrete showed alarming growth and the bridge was closed for traffic. Additional strain gauges were installed on vertical reinforcement bars and an assessment was carried out of the fatigue capacity of the bridge. It was found that the new strain gauges did not indicate any growth in strain and that the fatigue capacity was sufficient. The bridge could be opened again for traffic after being closed for five weeks. Monitoring drift in the strain gauges and fatigue are discussed.

    Download full text (pdf)
    fulltext
  • 36.
    Agredo Chavez, Angelica Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Gonzalez, Jaime
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Capacci, L.
    Politecnico di Milano, Milan, Italy.
    Biondini, F.
    Politecnico di Milano, Milan, Italy.
    Structural model updating of an existing concrete bridge based on load testing and monitoring data2023In: Life-Cycle of Structures and Infrastructure Systems / [ed] Fabio Biondini, Dan M. Frangopol, Taylor & Francis Group, 2023, Vol. 1, p. 3999-4006Conference paper (Other academic)
    Abstract [en]

    The backbone of European infrastructure was built after the end of the second World War and has reached, or is near to, the end of its nominal design life. This issue urges the development of structural assessment procedures that can provide infrastructure managers the information to make decisions for repairing, upgrading, or replacement. In this paper, a methodology based on load testing and Structural Health Monitoring (SHM) for the assessment of a 65- year-old prestressed concrete bridge located in Northern Sweden is presented. The retrieved data is used to develop and calibrate structural models with different levels of data completeness. The SHM procedure includes the evaluation of material properties by diagnostics, definition of the layout and installation of the instrumentation, test execution, and data analysis. A preliminary structural model is developed based only on the original design parameters, and it is sequentially updated with monitoring data retrieved during a performed proof loading test of the bridge.

  • 37.
    Agredo Chavez, Angelica Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Gonzalez, Jaime
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Bianchi, Silvia
    Politecnico di Milano, Milan, Italy.
    Biondini, Fabio
    Politecnico di Milano, Milan, Italy.
    Kukay, Brian
    Montana Technological University, Montana, United States.
    Available Tests to evaluate Residual Prestressing Forces in Concrete Bridges2022In: IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures - Report, International Association for Bridge and Structural Engineering / [ed] František Wald; Pavel Ryjáček, International Association for Bridge and Structural Engineering, 2022, p. 1123-1131Conference paper (Refereed)
    Abstract [en]

    The reduction of the structural capacity and eventual collapse of existing concrete bridges is often related to the loss of the initial prestressing forces. This loss can be associated to immediate or time dependent factors such as elastic shortening, creep, relaxation, loading, and cracking, among others. In addition, environmental factors can lead to corrosion of the strands with the subsequent reduction of their area, loss of bond with the concrete and additional cracking which in turn will influence the value of the residual prestress force and the bridge capacity. Therefore, the evaluation of such losses is critical in the decision-making process of defining a financial and environmental cost optimized intervention strategies (e.g., strengthening or replacement). In this paper, a detailed literature review regarding destructive and non-destructive methods for measuring the residual force in prestressed concrete bridges is carried out and used to develop a database of existing experimental tests.

    Download full text (pdf)
    fulltext
  • 38.
    Agredo Chavez, Angelica Maria
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Ulfberg, Adrian
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Gonzalez-Libreros, Jaime
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Data Validation of Strain-Based Monitoring Systems in Low Temperature Conditions, Case Study: The Kalix Bridge2023In: Building for the Future: Durable, Sustainable, Resilient - Proceedings of the fib Symposium 2023 - Volume 2 / [ed] Alper Ilki; Derya Çavunt; Yavuz Selim Çavunt, Springer, 2023, Vol. 2, p. 986-995Conference paper (Refereed)
    Abstract [en]

    Over the last decades, economic growth and sustained development have enforced the need to ensure reliable and long-lasting infrastructure network to guarantee serviceability and safety. Nevertheless, detrimental effects can lead over time to insufficient structural performance under increasing service loadings and extreme events. Hence, Structural Health Monitoring (SHM) arises as a solution to cope with the need of having timely and continuous data to assess the state of crucial structural assets, such as prestressed concrete bridges. On this matter, the validation of the retrieved data becomes essential for the risk-based decision making in the assessment of bridges, where selecting the most suitable monitoring system could allow to addressed main causes to the right phenomena of deterioration during the service life of the bridge. Consistently with these efforts, this paper deals with a comparative study between the data acquired by different strain-based sensors such as Fiber optic systems (FOS) and strain gauges that were installed to monitor a proof loading test developed on a 65-year-old balanced cantilever prestressed concrete bridge located in Northern Sweden. The monitored data led to establish main differences between emerging types of monitoring systems such as FOS to the well-based strain gauges when exposed to low temperature conditions. Conclusions regarding the influencing parameters between both retrieved data are drawn when evaluating the structural response under serviceability loading conditions is performed, supporting decision makers when different levels of structural assessment are required.

  • 39.
    Agredo Chávez, Angélica
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Gonzalez-Libreros, Jaime
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Wang, Chao
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Capacci, Luca
    Department of Civil and Environmental Engineering, Politecnico di Milano, Milan, Italy.
    Biondini, Fabio
    Department of Civil and Environmental Engineering, Politecnico di Milano, Milan, Italy.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Assessment of residual prestress in existing concrete bridges: The Kalix bridge2024In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 311, article id 118194Article in journal (Refereed)
    Abstract [en]

    The direct socio-economic consequences of the deterioration of aging infrastructure systems have triggered a continuous process of revising and updating current design standards and guidelines for critical network components. Specifically, long-term degradation processes demand the analysis and evaluation of vital structural assets such as prestressed concrete bridges. It is crucial to develop theoretically consistent, user-friendly, and non-destructive methodologies that engineering professionals can employ to prevent and mitigate potential catastrophic outcomes during the service life of these bridges. This study provides a thorough review of the available testing methods employed over the years for prestressed concrete bridges and introduces a comprehensive framework for evaluating existing methods for residual prestress force assessment. Through a multi-criteria selection process, the three most feasible tests were designed and carried out on an existing 66-year-old balanced cantilever box girder bridge exposed to freezing temperatures that affected the instrumentation plan and test execution. Finally, predictive models compliant with standard codes were calibrated based on the experimental results and the life cycle loss of prestress forces was evaluated to assess relevant bounding intervals. Findings reveal limited on-site testing and discrepancies between calculated residual forces and predictions by standard codes. The saw cut method showed a 18% difference from the initial applied prestress according to the prestress protocol, suggesting the use of a cover meter and concrete modulus evaluation for improved accuracy. The strand cutting method resulted in a 14% difference, emphasizing the need for stress redistribution assessment. The second-order deflection method showed a 6% difference, indicating a focus on enhanced boundary conditions and thorough sensitivity analysis for future investigations.

    Download full text (pdf)
    fulltext
  • 40.
    Aguilera, Nina
    et al.
    Efterklang.
    Naglitsch, Henrik
    Sweco.
    Olofsson, Katrin
    Strategigruppen.
    Beräkningsmanual Nord2000: för bullerberäkningar i väg- och järnvägsplaner2024Report (Other academic)
    Abstract [sv]

    Syftet med denna beräkningsmanual är att underlätta övergången från de nordiska beräkningsmodellerna (Nord96-Spår respektive Nord96-Väg) till Nord2000 vid beräkning av trafikbuller i väg- och järnvägsplaner. Manualen syftar även till att ge förutsättningar för att bullerutredningar inom olika projekt ska utföras på ett likvärdigt sätt. Målgruppen för beräkningsmanualen är akustikkonsulter som utför bullerberäkningar i Trafikverkets väg- och järnvägsprojekt.

    Download full text (pdf)
    Beräkningsmanual Nord2000
    Download (png)
    presentationsbild
  • 41. Agustsson, Larus
    Danish experiences with speed zones/variable speed limits2001In: Proceedings of the conference Traffic Safety on Three Continents: International conference in Moscow, Russia, 19-21 September, 2001 / [ed] Asp, Kenneth, Linköping: Statens väg- och transportforskningsinstitut, 2001, p. 793-804Conference paper (Other academic)
    Abstract [en]

    The first Danish Road Safety Action plan in 1989 reduced the number of fatalities and casualties by 30% by the year 2000. The goal of the new Danish Road Safety Action Plan is to reduce the number of fatalities and serious casualties by 40% from 1998 to the year 2012. One of the actions that will be used to actuate this plan is the implementation of speed management and speed zones. This paper discusses the Danish experience with speed zones and variable speed limits.

  • 42.
    Ahlberg, Sven-Olof
    et al.
    Kulturbyggnadsbyrån.
    Spade, Bengt
    Industriminnesbyrån.
    Våra broar: en kulturskatt2001Book (Other (popular science, discussion, etc.))
    Abstract [sv]

    Banverket och Vägverket förvaltar idag tillsammans cirka 17 500 broar. Den samlade kunskapen om dessa broars kultur- och teknikhistoriska värden har hittills varit ganska liten. För att råda bot på detta inventerade Vägverket och Banverket gemensamt under åren 1997-98 framförallt 1900-talets broar - industrisamhällets broar. Dessa broar som uppförts av industrisamhällets främsta byggnadsmaterial, stål och betong, har i många fall glömts bort.

  • 43.
    Ahlgren, Bengt
    et al.
    RISE Research Institutes of Sweden, Digital Systems, Industrial Systems.
    Claesson, Åsa
    RISE Research Institutes of Sweden, Digital Systems, Smart Hardware.
    Honfi, Daniel
    RISE Research Institutes of Sweden. Ramböll, Sweden.
    Kardeby, Victor
    RISE Research Institutes of Sweden, Digital Systems, Industrial Systems.
    Karoumi, Raid
    KTH Royal Institute of Technology, Sweden.
    Leander, John
    KTH Royal Institute of Technology, Sweden.
    Digitaliseringens möjligheter och utmaningar inom förvaltning och underhållsplanering av broar: Förstudie2020Report (Other academic)
    Abstract [en]

    Rapporten behandlar digitalisering – att införa ny digital teknik – i förvaltningsverksamheten av broar. Omfattningen är en förstudie med syftet att identifiera behovet av framtida forskning för en långsiktig utveckling av broförvaltningen. En grundläggande ansats var att en digitalisering ska minska behovet av kostsamma underhållsåtgärder men bibehålla en hög säkerhet för våra broar. Projektets mål var att samla information om digitala informationsmodeller som skapas under investeringsskedet, utvärdera överlämningen av digitala modeller till förvaltningsskedet, och värdera den eventuella nyttan med digital informationsinsamling för tillståndsbedömning och underhållsplanering. En viktig del av detta var beskrivningen av dagens förvaltningssystem och hur det skulle kunna utvecklas. Studierna har bedrivits genom en enkätundersökning med respondenter från konsultfirmor aktiva inom broprojektering, intervjuer med tekniska experter och litteratursökningar. Resultatet visar att projekteringen av broar idag huvudsakligen görs genom byggnads-informationsmodellering (BIM). Inriktningen är mot byggskedet där samordning och kommunikation bedöms vara de största nyttorna. Överlämningen till förvaltningen består dock av relationsritningar i formen av enkla ritningsfiler. Trots att Trafikverkets strategi för BIM beskriver att en informationsmodell bör leva kvar under hela brons livslängd, finns det tveksamheter huruvida en modell från projekteringen är lämplig som förvaltningsmodell. Istället lyfts andra metoder fram för att skapa en modell av det byggda utförandet. Till exempel optiska metoder för skanning och fotogrammetri. Förvaltningssystemen bör utvecklas med funktioner för att lagra och tillgängliggöra stora mängder digital information från sensorer maskinella inspektioner. Syftet är att minska osäkerheterna i det byggda utförandet och graden av nedbrytning, för att slutligen skapa ett bättre underlag för beslut om åtgärder. Ett framtida scenario är en digital tvilling som speglar den verkliga konstruktionen och uppdateras kontinuerligt genom sensordata. Gällande hårdvara för mätningar behöver sensorer och system utvecklas med avseende på energiförbrukning, energiskördning och underhållsåtgärder, t.ex. genom kombinationer av utbytbara komponenter med kort livslängd och andra delar med lång livslängd. Fiberoptiska sensorer visar på lovande egenskaper men utveckling behövs för att göra dem mer kostnadseffektiva i relation till konventionella sensorer.

    Download full text (pdf)
    fulltext
  • 44.
    Ahlm, Nils
    et al.
    Swedish Transport Administration.
    Martini, Veronika
    Swedish Transport Administration.
    Regeringsuppdrag att vidta åtgärder för planeringen av transportinfrastrukturen i Norrbottens och Västerbottens län2024Report (Other academic)
    Abstract [sv]

    Den 14 mars 2024 gav regeringen Trafikverket i uppdrag att vidta åtgärder för planeringen av transportinfrastrukturen i Norrbottens och Västerbottens län. 

    Enligt uppdraget avser regeringen att utarbeta en strategi för nyindustrialiseringen och samhällsomvandlingen i Norrbottens och Västerbottens län och ser stora möjligheter för norra Sverige att leda den nya industriella revolutionen och bli en motor för gröna innovationer. Regeringen ser ett stort behov av förstärkningar av vägnätet och järnvägsinfrastrukturen, inte minst strategiska investeringar för att möjliggöra och accelerera den industriella gröna omställningen i norra Sverige, exempelvis genom objekten i den nationella trafikslagsövergripande planen för transportinfrastrukturen för perioden 2022–2033 som avser Malmbanan. 

    Regeringen gav Trafikverket därför i mars 2023 i uppdrag (LI2023/02196) att beskriva aktuell status och aktuellt planeringsläge för de åtgärder i den nationella planen som har betydelse för att åtgärda eventuella brister och flaskhalsar som kan uppstå i transportsystemet med anledning av de större företagsetableringarna och företagsexpansionerna i Norrbottens och Västerbottens län. Trafikverket fick också i uppdrag att redogöra för möjligheterna att tidigarelägga de nämnda åtgärderna. Trafikverket redovisade uppdraget den 15 september 2023 (TRV 2023/42130). I sin redovisning redogör Trafikverket för möjligheterna att tidigarelägga ett antal planerade åtgärder – kapacitetshöjande åtgärder på järnvägen mellan Luleå och Kiruna, Norrbotniabanan och E4 förbifart Skellefteå – samt föreslår ett nytt objekt, Dubbelspår Luleå-Boden. 

    Download full text (pdf)
    Regeringsuppdrag att vidta åtgärder för planeringen av transportinfrastrukturen i Norrbottens och Västerbottens län
    Download (jpg)
    presentationsbild
  • 45.
    Ahlman, Lars
    et al.
    JS Konsult.
    Magnusson, Hans
    JS Konsult.
    Wilde, Bengt
    JS Konsult.
    Söderström, Jan
    JS Konsult.
    Cykeltrafikregler och utformning för ökad säkerhet och framkomlighet2022Report (Other academic)
    Abstract [sv]

    Denna rapport är framtagen med ekonomiskt stöd från Trafikverket Skyltfonden. Ståndpunkter, slutsatser och arbetsmetoder i rapporten reflekterar våra egna och överensstämmer inte med nödvändighet med Trafikverkets inom rapportens arbetsområde.  

    Vi har i vår rapport listat ett antal förslag på förändringar i lagar och förordningar som vi anser på ett bättre sätt skulle förtydliga korsningsreglerna för bilisterna och på det sättet förbättra framkomligheten och säkerheten för cyklisterna. De flesta av de fall vi studerat avser situationer där cyklisten kommer i konflikt med korsande biltrafik och där korsningsregeln ofta är tvetydig. Exempel på en sådan förändring är den som vi föreslår i trafikförordningen om väjningsregler för cyklister på en cykelbana intill en huvudled. Ett annat förslag är att vi vill tydliggöra att en cykelbana i anslutning till en cirkulationsplats inte ingår i körbanan. Därmed blir cykelbanan alltid en egen bana och med det trafikregler som följer av detta. Men den kanske viktigaste slutsatsen i vår studie är att väghållarna, som är ansvariga för utformningen av trafikmiljön, ofta inte är tillräckligt uppmärksamma på eller har kunskap om hur trafikregler och byggnadsteknisk utformning och gestaltning hänger ihop, för att på ett naturligt sätt understödja gällande trafikregler. Det finns många exempel på utformning där trafikanterna uppfattar att väjningsplikten är oklar. Vi vill särskilt peka på vikten av att en genomgående cykelbana i en korsning med en anslutande gata alltid måste ges en sådan utformning att det är tydligt för alla trafikanter att bilisten har väjningsplikt. Vi har därför i avsnittet om genomgående cykelbana listat grundläggande och önskvärda kriterier för utformningen av korsningen för att detta mål ska kunna nås.  Den tekniska utvecklingen innebär att det är allt svårare att ange vad som är en cykel och vi tror att den utvecklingen kommer att fortsätta. Det finns redan idag en- två- och trehjuliga ”cyklar” med och utan hjälpmotor som kan framföras i helt olika hastighet. Det är därför viktigt att stadsplaneringen sker med flexibilitet så att gaturummet kan användas på nya sätt över tid. Ramen för vad detaljplanen föreskriver måste därför vara tillräckligt bred för att kunna genomföra nya idéer utan att behöva starta det arbetsamma arbetet med en ny detaljplan. Det är olyckligt att det finns så många regler och begrepp som liknar varandra och som reglerar hur förare av fordon och andra trafikanter ska bete sig vid möten i trafiken. Vi anser att det därför är angeläget att göra en systematisk översyn av alla dessa regler och begrepp i trafikförordningen. Gällande trafikregler för cyklister och bilister är många och knappast möjliga att kunna ens för personer som är bevandrade i trafikförordningen. Detta gäller särskilt som cyklister är en mycket heterogen grupp. Till detta kan läggas att lagstiftaren har använt ett antal liknande formuleringar för att uttrycka delvis samma sak om hur cyklister och bilister ska förhålla sig till varandra.   För att vara tydligt för trafikanterna bör det dels finnas så få regler som möjligt, dels bör dessa vara formulerade så enhetligt som möjligt. Därtill behövs en översyn av när respektive regel ska gälla. Vårt förslag kan sammanfattas på följande sätt:

    • Reglerna ska vara få och enkla för att de ska kunna förstås och accepteras.• Reglerna ska anpassas till hur trafikanterna idag uppfattar "vad som gäller". • Samma regler ska gälla på likartade platser eller vid likartade situationer, till exempel lika såväl vid bevakade som obevakade platser. 

    Download full text (pdf)
    Cykeltrafikregler
  • 46. Ahlstrand, Ingemar
    Vad lär oss tredje spåret?: om demokrati, samhällsnytta och samhällskostnad1997In: Kulturmiljövård, ISSN 1100-4800, no 1, p. 91-94Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

    Aktörer med en stark roll i be­slutsprocessen kan ge sina särin­tressen en orimlig tyngd när poli­tikerna inte förmår att hävda be­slutsprocessens rationalitet, me­nar författaren. Trots att Kungs­holmenbanan funnits med i re­gionplanearbetet för Stockholm och förordats av många trafikex­perter finns ännu inte någon till­fredsställande utredning om ba­nan. Samhällsekonomiskt vore Kungsholmenbanan - det "raka spåret" - det mest lönsamma al­ternativet till tredje spåret över Riddarholmen.

    Download full text (pdf)
    fulltext
    Download (jpg)
    presentationsbild
  • 47.
    Ahlström, Christer
    et al.
    VTI, Swedish Natl Rd and Transport Res Inst, Linkoping, Sweden.
    Anund, Anna
    Linköping University, Department of Medical and Health Sciences, Division of Community Medicine. Linköping University, Faculty of Medicine and Health Sciences. VTI, Swedish Natl Rd and Transport Res Inst, Linkoping, Sweden.
    Fors, Carina
    VTI, Swedish Natl Rd and Transport Res Inst, Linkoping, Sweden.
    Åkerstedt, Torbjorn
    Stockholm Univ, Sweden; Karolinska Inst, Sweden.
    Effects of the road environment on the development of driver sleepiness in young male drivers2018In: Accident Analysis and Prevention, ISSN 0001-4575, E-ISSN 1879-2057, Vol. 112, p. 127-134Article in journal (Refereed)
    Abstract [en]

    Latent driver sleepiness may in some cases be masked by for example social interaction, stress and physical activity. This short-term modulation of sleepiness may also result from environmental factors, such as when driving in stimulating environments. The aim of this study is to compare two road environments and investigate how they affect driver sleepiness. Thirty young male drivers participated in a driving simulator experiment where they drove two scenarios: a rural environment with winding roads and low traffic density, and a suburban road with higher traffic density and a more built-up roadside environment. The driving task was essentially the same in both scenarios, i.e. to stay on the road, without much interaction with other road users. A 2 x 2 design, with the conditions rural versus suburban, and daytime (full sleep) versus night-time (sleep deprived), was used. The results show that there were only minor effects of the road environment on subjective and physiological indicators of sleepiness. In contrast, there was an increase in subjective sleepiness, longer blink durations and increased EEG alpha content, both due to time on task and to night-time driving. The two road environments differed both in terms of the demand on driver action and of visual load, and the results indicate that action demand is the more important of the two factors. The notion that driver fatigue should be countered in a more stimulating visual environment such as in the city is thus more likely due to increased task demand rather than to a richer visual scenery. This should be investigated in further studies.

  • 48.
    Ahmad, Numan
    et al.
    National University of Sciences and Technology, Pakistan.
    Ahmed, Anwaar
    National University of Sciences and Technology, Pakistan.
    Shah, Akhtar Ali
    University of Peshawar.
    Effectiveness of enforcement of seatbelt law: an exploratory empirical analysis using aggregate data2018Conference paper (Refereed)
    Abstract [en]

    Increasing motorization has enhanced the risk of road traffic crashes worldwide. Enforcing legislation on key risk factors such as seatbelt use by vehicle occupants is critical in reduction of road crash fatalities and injuries. This study estimated an ordered probit model to explore the relationship between effectiveness of enforcement of seatbelt law and different exploratory variables using data from World Health Organization. This study categorizes the enforcement of seatbelt law into four different levels including very low, low, medium and high. Through this study an attempt has been made to establish the relationship between effectiveness of enforcement of seat belt laws and socio-economic conditions, road crash fatalities, road safety legislation and public policies. Model results revealed that effectiveness of enforcement of seat belt law is significantly associated with road crash fatalities per thousand registered vehicles, legislation on cell phone use while driving, availability of training in emergency medicine for doctors, existence of national or sub-national policy for promoting walking and cycling, the existence of funded lead agency and maximum speed limit on rural road of a country. This research aims to provide a preliminary insight to planners and enforcement agencies to identify significance of seatbelt enforcement and suggest measures compatible to the typical socio-cultural and institutional set up for making the roads safer.

    Download full text (pdf)
    fulltext
  • 49.
    Ahmadiyan, Sara
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Mehari, Daniel
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Estimation of the characteristic in-situ compressive strength class of concrete structures - A case study of the Skuru bridge2021Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    It is inevitable that Structures become older and their intended use changes or the structuralcodes regulations change. In some regions the damage from seismic activities is a possibility.It becomes, therefore crucial to assess the structural capacity of such structures. The purposeof this study is to assess the different methods used for testing and estimating thecharacteristic in-situ compressive strength which is the most vital parameter required instructural assessment.

    The focus of the study is for existing structures where there is no prior knowledge about theconcrete strength. This study first investigates and evaluates the merits and demerits of thesemethods for investigation of the condition of in-situ compressive strength of concrete inexisting structures. A case study of the Skuru bridge that was built in 1914 was utilized forthis study. The study is based on information of the construction data and some results fromprior investigation performed by the company COWI. Afterwards, non-destructive tests werecarried out with the UPV and Rebound hammer to assess the quality of the concrete.

    In addition, the study assesses the use of different interpretation methods with regards toreliability and practical application. The results were interpreted in accordance to theEuropean codes, Swedish codes and other interpretation methods. The difference of theresults from the different interpretation methods are compared and evaluated for reliabilityand efficiency.

    The test results confirmed that the concrete consisted of the same strength class. However,the results from the different interpretation methods are dissimilar. The reason for obtainingdifferent results is because the methods depend on different methodologies. The studyshowed that some methods can sometimes overestimate the results and become unsafe forstructural assessment. On the contrary, the other methods can yield lower but safer estimates.

    Moreover, the use of small number of cores is evaluated for various methods. The reasons arebecause in practice, the preference is to avoid large number of cores. As a result, it isrecommended to apply care and proper judgment in selection of the methods andinterpretation of the results. It is also recommended to consider the methods with respect tothe aim of the investigation, their limitations and assumptions.

    Download full text (pdf)
    fulltext
  • 50.
    Ahmed, Abubeker
    et al.
    Swedish National Road and Transport Research Institute, Infrastructure, Pavement Technology.
    Carlsson, Håkan
    Swedish National Road and Transport Research Institute, Infrastructure, Measurement technology and engineering workshop.
    Lundberg, Thomas
    Swedish National Road and Transport Research Institute, Infrastructure, Infrastructure maintenance.
    Utvärdering av gummiasfalt: provväg E22 Mönsterås : etapp 12019Report (Other academic)
    Abstract [en]

    Laboratory and filed investigations have been carried out to evaluate the performance of rubber modified asphalt test road on E22 Mönsterås.

    The laboratory investigations indicated that there are no significant differences in stiffness and shear modulus between the reference and rubber modified mixtures. The rubber modified mixture however showed slightly lower phase angle compared to the reference mixture which indicate that the rubber modified mixture is more elastic. The rubber modified mixtures also showed lower modulus at lower temperatures and slightly higher modulus at higher temperature which are desired properties for resistance against low temperature cracking and permanent deformation respectively. The fatigue tests indicated that the rubber modified asphalt mixture has slightly better fatigue cracking performance. But the difference is not significant.

    The road surface profile measurements indicated no significant differences between the reference and asphalt rubber sections. It is however early to draw conclusions after one year of traffic therefore additional follow-up of the test sections is needed to draw a conclusion.

    Download full text (pdf)
    fulltext
1234567 1 - 50 of 6032
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf