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  • 301.
    Nilsson, Martin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Jonasson, Jan-Erik
    Wallin, Kjell
    Emborg, Mats
    Bernander, Stig
    Elfgren, Lennart
    Crack prevention in walls and slabs: the influence of restraint1999In: Innovation in concrete structures: design and construction: design and construction ; proceedings of the international conference held at the University of Dundee, Scotland, UK on 8-10 September 1999 / [ed] Ravindra K. Dhir; M. Roderick Jones, London: Thomas Telford Ltd , 1999, p. 461-471Conference paper (Refereed)
  • 302.
    Nilsson, Martin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Ohlsson, Ulf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Effects of surface reinforcement on bearing capacity of concrete with anchor bolts2011In: Nordic Concrete Research, ISSN 0800-6377, Vol. 2011, no 44, p. 161-174Article in journal (Refereed)
    Abstract [en]

    66 tests of the influence of surface reinforcement on the tensile load capacity of cast-in fasteners have been carried through. In the tests threaded rods ∅30 mm with a ∅45 mm nut at the end were cast-in centrically in concrete slabs (1.2 m × 1.2 m × 0.3 m up to 2.2 m × 2.2 m × 0.6 m). The amount of surface reinforcement was varied from 0% up to about 1.2%. There is a considerable increase in the load capacity with surface reinforcement present. The increase depends on the geometry and the amount and placement of the reinforcement.

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  • 303. Nilsson, Martin
    et al.
    Ohlsson, Ulf
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Partialkoefficienter för hållfasthet i betongbroar längs Malmbanan1999Report (Other academic)
    Abstract [sv]

    Denna rapport redovisar två metoder att bestämma nyanserade värden på betonghållfasthetens partialkoefficienter för befintliga betongbroar längs Malmbanan. Rapporten presenterar därefter dimensionerande drag- och tryck-hållfasthetsvärden för sju broar mellan Luleå och Boden. Hållfasthetsvärden är baserade dels på de nya partialkoefficienterna, dels på provresultat, Thun et al (1999). Provresultaten ligger till grund för karakteristiska hållfasthetsvärden som bestämts enligt BBK94 (1995). Partialkoefficienter för hållfasthetsvärdena har bestämts med vad som i rapporten benämns tabellmetoden och sannolikhetsteoretisk metod. Tabellmetoden är hämtad från NKB (1978) och NKB (1987). Metoden bygger, som namnet indikerar, på tabeller varur fyra delfaktorer till partialkoefficienten bestäms. Faktorerna behandlar (1) osäkerheter i karakteristiska värden och i förhållandet mellan hållfasthet i konstruktion och i provkropp etc.; (2) osäkerheter i beräk-ningsmodeller; (3) brottkaraktär (segt eller sprött) och (4) omfattningen av kontroll vid uppförandet av broarna. Den sannolikhetsteoretiska metoden för att bestämma partialkoefficienter tar i sin tur också hänsyn till osäkerheter i karakteristiska värden, i förhållandet mellan hållfasthet i konstruktion och i provkropp och osäkerheter i beräkningsmodeller. Metoden tar även med partialkoefficienter för laster, vilka här har satts till normenliga värden förutom tåglastens partialkoefficient som satts till 1,1 enligt en utredning av Östlund (1997) i bilaga A och används här endast vid statistiska beräkningar och godtas därför inte av Banverket. Inverkan av tåglast och last av betong och ballast ingår. Även broarnas individuella längder beaktas då tåglasternas dynamiska förstoringsfaktorer bestäms. Resultaten av bestämning av partialkoefficienten med tabellmetoden och den sannolikhetsteoretiska metoden ger för de sju broarna mellan Luleå och Boden något skilda resultat. Tabellmetoden ger generellt högre värden än den sannolikhetsteoretiska metoden. Tabellmetodens värden varierar mellan 1,44 och 1,95 för draghållfastheten och mellan 1,44 och 1,48 för tryckhållfastheten. Värdena från den sannolikhetsteoretiska metoden ligger ca 15% lägre. Vi förordar i första hand, på grund av sin enkelhet, att tabellmetoden används vid bestämning av partialkoefficienten. Den sannolikhetsteoretiska metoden är något mer komplicerad och måste ofta kompletteras med kvalificerade bedömningar. De dimensionerande hållfasthetsvärdena som bestäms i rapporten är betydligt högre än de värden som föreskrivna hållfasthetsklasser ger. Den största inverkan på detta har de provade hållfasthetsvärdena, som ligger väsentligt över de föreskrivna värdena. Partialkoefficienternas inverkan är mindre. Rapporten avslutas med en diskussion om inverkan av hållfasthetens variation inom konstruktionsdelar, vilken kan ha stor inverkan på bärförmågan. Likaså har läget för uttagna provkroppar i förhållande till aktuellt beräkningssnitt betydelse. Båda dessa faktorer bör ingå vid en bestämning av hållfastheters partialkoefficienter i befintliga konstruktioner.

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  • 304.
    Nilsson, Martin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Ohlsson, Ulf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Emborg, Mats
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Fastenings (anchor bolts) in concrete structures: influence of surface reinforcement2012In: Concrete Structures for Sustainable Community: proceedings of the International FIB Symposium 2012, Stockholm, Sweden, 11 - 14 June 2012 / [ed] Dirch H. Bager; Johan Silfwerbrand, Stockholm: Swedish Concrete Association , 2012, p. 419-422Conference paper (Refereed)
    Abstract [en]

    Tests have been carried out to study the influence of surface reinforcement on the load bearing capacity of cast-in headed bars. In 66 tests, rods with a diameter of Φ30 mm and a Φ45 mm nut at the end, were cast-in place centrically in concrete slabs. Width, length and thickness of the slabs varied from 1.2 m × 1.2 m × 0.3 m up to 2.2 m × 2.2 m × 0.6 m. The top reinforcement varied from 0% to about 1.2% (Φ 16 #100). A considerable increase in the load-bearing capacity was noted. The increase depends on the geometry and the amount and placement of the reinforcement. A numerical model to evaluate the influence is proposed.

  • 305.
    Noghabai, Keivan
    et al.
    Luleå University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Extension to Swedish code for high-strength concrete1996In: Proceedings: Nordic Concrete Research Meeting, Espoo, Finland 1996, Oslo: Norsk Betongforening , 1996, p. 133-134Conference paper (Refereed)
  • 306.
    Noghabai, Keivan
    et al.
    Luleå University of Technology.
    Olofsson, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Bond between concrete and reinforcement modelled by fracture mechanics1995In: Proceedings of Nordic Symposium on Modern Design of Concrete Structures / [ed] Kirsten Aakjaer, Aalborg: Department of Building Technology and Structural Enginering, Aalborg University , 1995, p. 85-96Conference paper (Refereed)
  • 307. Noghabai, Keivan
    et al.
    Olofsson, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Fracture mechanics applied to bond1997In: Advanced design of concrete structures: [papers presented at the Symposium on Advanced Design of Concrete Structures, held in Chalmers University of Technology in Göteborg, Sweden on June 12 - 14, 1997] / [ed] Kent Gylltoft, Barcelona: International Center for Numerical Methods in Engineering (CIMNE), 1997, p. 57-64Conference paper (Refereed)
  • 308. Ohlsson, Ulf
    et al.
    Daerga, Per-Anders
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Fracture energy and fatigue strength of unreinforced concrete beams at normal and low temperatures1990In: Engineering Fracture Mechanics, ISSN 0013-7944, E-ISSN 1873-7315, Vol. 35, no 1-3, p. 195-203Article in journal (Refereed)
    Abstract [en]

    Results are presented from tests where the fracture energy and the fatigue strength have been determined for unreinforced concrete beams. The tests were performed at temperatures between +20 and −35°C with concrete with compressive strength varying between 25 and 100 MPa.

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  • 309. Ohlsson, Ulf
    et al.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Anchor bolts analyzed with fracture mechanics1991In: Fracture Processes in Concrete, Rock and Ceramics: Proceedings of the International RILEM/ESIS Conference / [ed] J.G.M. van Mier; J.G. Rots; A. Bakker, London: Taylor and Francis Group , 1991, p. 887-897Conference paper (Refereed)
  • 310.
    Ohlsson, Ulf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Anchor bolts modelled with fracture mechanics1990In: Proceedings: Nordic Concrete Research Meeting : Trondheim 1990 / [ed] Jens Jacob Jensen, Oslo: Norsk Betongforening , 1990, p. 270-271Conference paper (Refereed)
  • 311.
    Ohlsson, Ulf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Infästningar i betongkonstruktioner analyserade med brottmekanik1990In: Bygg och Teknik, ISSN 0281-658X, E-ISSN 2002-8350, no 7, p. 57-59Article in journal (Other (popular science, discussion, etc.))
  • 312.
    Ohlsson, Ulf
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Tests of the load-bearing capacity of anchor bolts1993In: Fracture and damage of concrete and rock : FDCR-2: proceedings of the second International Conference on Fracture and Damage of Concrete and Rock, Vienna, Austria, 9-13 November 1992 / [ed] H.P. Rossmanith, London: E & F N Spon (An imprint of Routledge) , 1993, p. 579-587Conference paper (Refereed)
  • 313.
    Olofsson, Ingvar
    et al.
    Skanska Teknik, Göteborg.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sustainable Bridges: Assessment for future traffic demands and longer lives2004In: Bridge Maintenance, Safety, Management and Cost: proceedings of the second International Conference on Bridge Maintenance, Safety and Management, 18-22 October 2004, Kyoto, Japan / [ed] Elichi Watanabo; Dan M. Frangopol; Tomoaki Utsnoniya, London: Taylor and Francis Group , 2004, p. 369-370Conference paper (Refereed)
  • 314.
    Olofsson, Ingvar
    et al.
    Skanska Teknik, Göteborg.
    Elfgren, Lennart
    Bell, Brian
    Network Rail, London.
    Paulsson, Björn
    Banverket, Borlänge.
    Niederleithinger, Ernst
    BAM, Berlin.
    Jensen, Jens Sandager
    COWI A/S, Lyngby.
    Feltrin, Glauco
    EMPA, Zurich.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Cremona, Christian
    LCPC, Paris.
    Kiviluoma, Risto
    North Finnish Building Cluster, Helsinki.
    Bien, Jan
    Wroclaw University of Technology.
    Assessment of European railway bridges for future traffic demands and longer lives: EC project "sustainable bridges"2005In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 1, no 2, p. 93-100Article in journal (Refereed)
    Abstract [en]

    A European Integrated Research Project has recently been started within the 6th Framework Program of the European Commission. The project aims at improved methods for the upgrading of existing railway bridges within the European railway network. The main objectives of the project are to increase the transport capacity by allowing higher axle loads and by increasing the maximum speeds. Other objectives are to increase the residual lifetime of existing bridges and to enhance management, strengthening and repair systems. The overall goal is to enable the delivery of improved capacity without compromising the safety and economy of the working railway. A consortium consisting of railway bridge owners, consultants, contractors, research institutes and universities carry out the project, having a gross budget of more than 10 million Euros. Funding from the European Commission covers a major portion of the four-year project costs

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  • 315.
    Olofsson, Jan
    et al.
    Skanska.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Bell, Brian
    Paulsson, Björn
    Niederleithinger, Ernst
    Jensen, Jens S.
    Feltrin, Glauco
    Täljsten, Björn
    Cermona, Christian
    Kiviluoma, Risto
    Bien, Jan
    Sustainable bridges, a European integrated research project: background and overview2007In: Sustainable bridges: assessment for future traffic demands and longer lives / [ed] Jan Bien; Lennart Elfgren; Jan Olofsson, Wrocław: Dolnoslaskie Wydawnictwo Edukacyjne , 2007, p. 29-49Conference paper (Refereed)
  • 316.
    Olofsson, Jan
    et al.
    Skanska Sverige AB.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Paulsson, Björn
    Banverket.
    "Sustainable Bridges " - Hållbara broar2008In: V-byggaren : väg- och vattenbyggaren, ISSN 0283-5363, no 3, p. 12-16Article in journal (Other academic)
    Abstract [sv]

    I december 2003 påbörjades ett fyraårigt europeiskt forskningsprojekt "Sustainable Bridges" (SB). Målet för projektet var att ta fram metoder för att uppgradra och förstärka befintliga järnvägsbroar. Broarna skall klara högre tåglaster och högre axellaster och samtidigt få ökad livslängd. Efter fyra års intensivt arbete har projektet nu avslutats och de sista rapporterna är på väg till Bryssel. Mer information om projektet finns på www.sustainablebridges.net Udgivelsesdato: maj

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  • 317.
    Olofsson, Jan
    et al.
    Skanska Sverige.
    Hedlund, Hans
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Skanska Sverige.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Overall Project Guide: Sustainable Bridges - Assessment for Future Traffic Demands and Longer Lives SB9.22007Report (Refereed)
    Abstract [en]

    This Overall Project Guide gives a general overview of the main outputs of the Integrated Research Project "Sustainable Bridges - Assessment for Future Traffic Demands and Longer Lives" founded by the European Commission within its 6th Framework Programme. It guides the bridge engineers, operators and managers through the number of technical guidelines and reports developed within the project, and it shows where to find relevant technical information for the specific activity related to operation, maintenance and management of existing railway bridges. Furthermore, it gives some guidance on the number of possible approaches and methods, presented in the project guidelines and reports that might be helpful in upgrading existing railway bridges for higher speeds and loads or that might help to extend their service life.

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    SB - Overall Project Guide
  • 318.
    Olofsson, Thomas
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Noghabai, Keivan
    Ohlsson, Ulf
    Elfgren, Lennart
    Anchorage and bond properties in concrete1995In: Fracture of brittle, disordered materials: concrete, rock and ceramics : proceedings of the International Union of Theoretical and Applied Mechanics (IUTAM) Symposium on Fracture of Brittle, Disordered Materials: Concrete, Rock and Ceramics / [ed] G. Baker; B.L. Karihaloo, London: Taylor and Francis Group , 1995, p. 525-543Conference paper (Refereed)
  • 319.
    Paulsson, Björn
    et al.
    Trafikverket, Uppsala.
    Bell, Brian
    Univ of Surrey, Guilford.
    Schewe, Britta
    Deutsche Bahn, Berlin .
    Jensen, Jens Sandager
    COWI AS, Lyngby.
    Carolin, Anders
    Trafikverket, Luleå.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Results and Experiences from European Research Projects on Railway Bridges2016In: 19th IABSE Congress Strockholm 21-23 September 2016: Challenges in Design and Construction of an Innovative and Sustainable Built Environment, CH - 8093 Zürich, Switzerland, 2016, p. 2570-2578Conference paper (Refereed)
    Abstract [en]

    Starting in 2003 the European Union has funded three consecutive research projects dealing with maintenance, life length, capacity and repair/strengthening of railway bridges.  The main results are that many bridges are capable of carrying increased loads and can have an increased service life if up to date technologies are used for assessment, monitoring, maintenance and strengthening.  

    In order to obtain good value for the money spent in the projects, it is important to plan, coordinate and manage the projects in an efficient way. Long range projects of four years seem to be more effective than shorter projects of two and three years.

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  • 320.
    Paulsson, Björn
    et al.
    Charmec, Chalmers tekniska högskola.
    Ekberg, Anders
    Charmec, Chalmers tekniska högskola.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Upgrading of freight railways to meet operational and market demands2018In: Proceedings of 7th Transport Research Arena, TRA 2018, April 16–19, 2018, Vienna, Austria, 2018Conference paper (Refereed)
    Abstract [en]

    The European objective of a modal shift of freight transports to railways will require extensive upgrading of existing railway lines since very few dedicated freight railways are currently being built and existing lines were built for traffic demands at the time of construction. A transition to increased and enhanced railway freight operations can therefore be costly and complicated. To minimize negative effects, a guideline for upgrading was developed within the Capacity4Rail project. The current paper presents the major findings from this guideline. In particular it outlines different upgrading possibilities and their implications, and details structured approaches to upgrading analyses. Setting out from the Capacity4Rail handbook, the current paper discusses possibilities for upgrading of substructures, bridges, tunnels, and the track structure. In these areas, an overview of challenges and possibilities is presented together with examples of experience from operational upgrading. The paper concludes that freight line upgrading using a more streamlined approach as outlined in the guideline is a necessity if EU objectives on modal shifts in transportation are to be met. Further, it demonstrates why a political drive is necessary to increase efforts to upgrade freight lines.

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    Paper
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    Poster
  • 321.
    Paulsson, Björn
    et al.
    Trafikverket, UIC.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Chryssanthopoulos, Marios
    University of Surrey.
    Schewe, Britta
    DB, Deutsche Bahn.
    Bharadwaj, Ujjwal
    TWI, Cambridge.
    Castlo, David
    NR, Network Rail.
    Bell, Brian
    NR, Network Rail, UIC.
    Paul, Adeline
    ARTTIC.
    MAINLINE Project Results - A Summary: MAINtenance, renewal and improvement of rail transport INfrastructure to reduce Economic and environmental impacts2014Report (Refereed)
    Abstract [en]

    Growth in demand for rail transportation across Europe is predicted to continue.Much of this growth will have to be accommodated on existing lines that contain old infrastructure. This demand will increase both the rate of deterioration of these elderly assets and the need for shorter line closures for maintenance or renewal interventions. However, interventions on elderly infrastructure will also need to take account of the need for lower economic and environmental impacts. This means that new interventions will need to be introduced. In addition tools will need to be developed to inform decision makers about the economic and environmental consequences of different intervention options being considered.

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  • 322.
    Paulsson, Björn
    et al.
    UIC.
    Olofsson, Jan
    Skanska.
    Hedlund, Hans
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Bell, Brian
    Network Rail.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sustainable bridges: results from a European integrated project2010In: Large structures and infrastructures for environmentally constrained and urbanised areas: 34th International Symposium on Bridge and Structural Engineering, Venice, Italy, September 22 - 24, 2010, Zurich: International Association for Bridge and Structural Engineering, 2010Conference paper (Refereed)
    Abstract [en]

    In Europe there are more than 1 million bridges, many of  them older than 50 years and quite a few of the railway bridges even have an age of more than100 years. These bridges represent a large value. Often there is a wish to increase speed and loads on existing bridges and then the question is if a bridge can be strengthened to fulfil the demands, or if it has to be replaced with a new one? This was the background for a European integrated research project within the 6th Framework Programme named "Sustainable Bridges". The project  was carried out between 2003 and 2007 with 32 partners from 12 countries and with a gross budget of more than 10 million Euros.  The aim of the project was to help to increase the use of the European railway network. For bridges, this can only be achieved by allowing higher axle loads on freight vehicles and by increasing the maximum permissible speed of passenger trains. In turn, any strengthening or maintenance work on the existing bridge stock to help in meeting this challenge must be undertaken without causing unnecessary disruption to the carriage of passengers and goods, and without compromising the safety and economy of the working railway. The project has developed many background documents and the following four major guidelines:(a) Inspection and Condition Assessment of Railway Bridges (b) Load and Resistance Assessment of Railway Bridges (c) Monitoring of Railway Bridges (d) Repair and Strengthening of Railway Bridges The results have been tested and demonstrated on several bridges in order to promote better engineering solutions which may produce savings throughout Europe. In the paper reflections on the efficiency and dissemination of the project will be given as well as examples of results and how they now are implemented.  All major results from the project are available at the website http://www.sustainablebridges.net/.

  • 323.
    Paulsson, Björn
    et al.
    Trafikverket; UIC, Paris, France; Charmec, Chalmers.
    Thunborg, Micael
    Trafikverket.
    Nelldahl, Bo-Lennart
    KTH.
    Ferriera, Tiago
    IST.
    Escriba Marin, Sergio
    CEMOSA.
    Roderiges Placa, Miguel
    ADIF.
    Nielsen, Jens
    Chalmers tekniska högskola.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Kabo, Elena
    Charmec, Chalmers tekniska högskola.
    Ekberg, Anders
    Charmec, Chalmers tekniska högskola.
    Larsson Kråik, Per-Olof
    Trafikverket.
    Upgrading of infrastructure in order to meet new operation and market demands2017Report (Refereed)
    Abstract [en]

    The European objective of a modal shift of freight transports to railways will require extensive upgrading of existing railway lines since very few dedicated freight railways are currently being built and existing lines were built for traffic demands at the time of construction. A transition to increased and enhanced railway freight operations can therefore be costly and complicated. To minimize negative effects, a guideline for upgrading was developed within the Capacity4Rail project. This handbook presents the major findings. In particular it outlines different upgrading possibilities and their implications, and details structured approaches to upgrading analyses. It discusses possibilities for upgrading of substructures, bridges, tunnels, and the track structure. In these areas, an overview of challenges and possibilities is presented together with examples of experience from operational upgrading. It concludes that freight line upgrading using a more streamlined approach as outlined in the guideline is a necessity if EU objectives on modal shifts in transportation are to be met. Further, it demonstrates why a political drive is necessary to increase efforts to upgrade freight lines.

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    fulltext
  • 324. Paulsson, Björn
    et al.
    Töyrä, Björn
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Ohlsson, Ulf
    Danielsson, Georg
    Increased loads on railway bridges of concrete1997In: Advanced design of concrete structures: [papers presented at the Symposium on Advanced Design of Concrete Structures, held in Chalmers University of Technology in Göteborg, Sweden on June 12 - 14, 1997] / [ed] Kent Gylltoft, Barcelona: International Center for Numerical Methods in Engineering (CIMNE), 1997, p. 201-206Conference paper (Refereed)
  • 325.
    Pike, Clinton W
    et al.
    Texas EMC Products, Woodlands, TX77380, USA.
    Ronin, Vladimir
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    High volume Pozzolan concrete: three years of industrial experience in Texas with CemPozz2009In: Concrete in Focus, Vol. 8, no 2, p. 22-27Article in journal (Other academic)
    Abstract [en]

    High Volume Pozzolan Concrete (HVPC) can be manufactured with low carbon dioxide footprint and energy consumption with the help of a new technology based on Energetically Modified Cement (EMC). The technology consists of mechanical processing a blend of ordinary portland cement (PC) and a pozzolan (Class F fly ash) through multiple high intensity grinding mills. The process imparts an increased surface activation of the PC and the pozzolan particles. Fly ash may be processed with all cements forming ready-to-use cement. Alternatively, fly ash can be processed with a small amount of cement (circa 5% by weight) and used as a pozzolan added to the concrete mixer. The latter product is called CemPozz and has been produced from 2004 by Texas EMC Products, Ltd, at the Limestone plant in Jewett, Texas. It can replace up to 60% of the PC in concrete. The performance of CemPozz (mechanically processed pozzolan) in concrete is equivalent to Grade 100 blast furnace slag in accordance with ASTM C 989 "Standard Specification for Ground Granulated Blast-Furnace Slag for Use in Concrete and Mortars."Th e strength of HVPC with 50% CemPozz is comparable to concrete made of ordinary portland cement, the setting time is similar, with improvements to alkali-silica reactivity mitigation and drying shrinkage. Concretes produced with CemPozz also have much higher sulfate resistance, very low permeability to chloride ions and are characterized by a signifi cantly reduced cracking.Th ere are three environmental benefi ts with the EMC-based HVPC: (i) You can activate a fl y ash that otherwise would not be suitable for high replacement of PC in concrete, (ii) You can reduce the CO 2 footprint by using a much less amount of clinker as concrete binder, and (iii) You can reduce the energy consumption associated with the binder. Calculations show that as much as 45% can be saved in energy with 45% less CO2 emissions when 50% fl y ash of cement mass is used with the EMC technology. During the period 2004-2007, over two million cubic yards (1.5 million cubic meters) of High Volume Pozzolan Concrete (HVPC) made with CemPozz have been manufactured in Texas and eff ectively used for different applications in Texas (highway paving, housing concrete, shotcrete and blocks). TX DOT and PENNDOT have included CemPozz in their specifications, which allow 50% replacement of portland cement by weight. Udgivelsesdato: March/April

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  • 326.
    Plos, M.
    et al.
    Chalmers .
    Lundgren, K.
    Chalmers.
    Rempling, R.
    Chalmers .
    Gylltoft, K.
    Chalmers.
    Cervenka, J.
    CERVENKA.
    Thelandersson, S.
    LTH.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Herwig, A.
    EPFL.
    Brühwiler, E.
    EPFL.
    Rosell, E.
    SRA.
    Gillesen, C.
    SRA.
    Non-Linear Analysis and Remaining Fatigue Life of Reinforced Concrete Bridges2007Report (Refereed)
    Abstract [en]

    The work provides methods for non-linear structural analysis and fatigue safety evaluation in assessment of existing railway bridges. The use of non-linear analysis leads to higher load carrying capacities, but also to improved understanding of the structural response, forming a better basis for decisions in the assessment. The methods for fatigue assessment lead to increased remaining service life of reinforced concrete railway bridges.

    The achievements of the work are:

    • Models for assessment of concrete bridges by non-linear analysis are described, and examples and general recommendations for practical application of the methods aregiven.

    • An overview of the effect of corrosion on the bond properties has been developed through non-linear analyses and tests found in literature. Recommendations for practical assessment of anchorage capacity in corroded railway concrete bridges are presented.

    • The determination of reliable in-situ material properties in old concrete bridges is described,including properties for fully probabilistic analysis. A particular aim was to develop better methods to describe development of concrete properties with age and degree of hydration.

    • Recommendations are given regarding re-distribution of sectional forces and moments, obtained through linear structural analysis (with FEM). In a case study, a typical slab bridge was designed using different methods, and its response evaluated through nonlinearanalyses.

    • A good understanding of the load-carrying mechanisms in combined bending-shear-torsion gives a possibility to make more accurate assessments than with standard code methods. Methods and examples are presented.

    • A state-of-the-art review of fatigue behaviour of reinforced concrete railway bridges is presented and a methodology to assess the remaining fatigue life of existing reinforced concrete bridges subjected to railway traffic is developed.

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    SB 4.5
  • 327.
    Plos, Mario
    et al.
    Chalmers University of Technology.
    Gylltoft, K.
    Chalmers University of Technology.
    Lundgren, K.
    Chalmers University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Cervenka, J.
    Cervenka Consulting, Praha.
    Brühwiler, E.
    École Polytechnique Fédérale de Lausanne.
    Thelandersson, S.
    Lund University of Technology.
    Rosell, Ebbe
    Swedish Road Administration, Borlänge.
    Structural assessment of railway concrete bridges: non-linear analysis and remaining fatigue life2006In: Bridge Maintenance, Safety, Management, Life-Cycle Performance and Cost: Proceedings of the third International Conference on Bridge Maintenance, Safety and Management. IABMAS'06 / [ed] Paulo J. da Sousa Cruz; Dan M Frangopol; Luis C Canhoto Neves, London: Taylor and Francis Group , 2006, p. 271-Conference paper (Refereed)
    Abstract [en]

    For a sustainable development in Europe, there is a need to at least double the railway transports in the coming 20 years. In order to reach this, the residual service lives of existing concrete bridges need to be extended at the same time as they are subjected to higher axle loads, higher railway speeds and heavier traffic intensity. Today, many concrete bridges are replaced or strengthened because their reliability cannot be guaranteed based on the structural assessments made. The aim of the work presented here is to provide enhanced assessment methods that are able to prove higher load carrying capacities and longer fatigue lives for existing concrete railway bridges. One main objective is to facilitate the use of non-linear analysis for structural assessment. In addition to higher load carrying capacities, the methods give improved understanding of the structural response, forming a better basis for decisions in the assessment. Another main objective is to improve knowledge about the fatigue behaviour of concrete bridges and to develop realistic methods for the evaluation of remaining fatigue life of existing bridges. The emphasis here is on short-span bridges and secondary elements. The work presented is a part of the ongoing EU-project Sustainable Bridges. The results will be implemented in the Guideline for Load and Resistance Assessment of existing European Railway Bridges that is being developed

  • 328. Plos, Mario
    et al.
    Gylltoft, Kent
    Jeppson, Joakim
    Carlsson, Fredrik
    Thelandersson, Sven
    Enochsson, Ola
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Evaluering av bärförmåga hos broar med hjälp av förfinade analysmetoder: ett samarbetsprojekt mellan LTH, LTU och Chalmers2004Report (Other academic)
  • 329.
    Plos, Mario
    et al.
    Chalmers University of Technology.
    Gylltoft, Kent
    Chalmers University of Technology.
    Lundgren, Karin
    Chalmers University of Technology.
    Cervenka, Jan
    Cervenka Consulting, Praha.
    Herwig, Andrin
    EPFL, Lausanne.
    Brühwiler, Eugen
    EPFL, Lausanne.
    Thelandersson, Sven
    Lund University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Rosell, Ebbe
    Swedish Road Administration, Borlänge.
    Structural assessment of concrete bridges2008In: Nordic Concrete Research, ISSN 0800-6377, no 2, p. 99-111Article in journal (Refereed)
    Abstract [en]

    The paper summarizes the work on concrete bridges performed in the EU project Sustainable Bridges. The work provides enhanced assessment methods that are able to provide higher load-carrying capacities and longer fatigue lives for exixixting concrete railway bridges. The work is also presented in a Guideleine available at www.sustainablebridges.net

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  • 330. Plos, Mario
    et al.
    Gylltoft, Kent
    Lundgren, Karin
    Cervenka, Jan
    Thelandersson, Sven
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Herwig, Andrin
    Bruhwiler, Eugen
    Rosell, Ebbe
    Structural assessment of concrete railway bridges2007In: Sustainable bridges: assessment for future traffic demands and longer lives / [ed] Jan Bien; Lennart Elfgren; Jan Olofsson, Wrocław: Dolnoslaskie Wydawnictwo Edukacyjne , 2007, p. 251-260Conference paper (Refereed)
  • 331.
    Plos, Mario
    et al.
    Chalmers University of Technology.
    Gylltoft, Kent
    Chalmers University of Technology.
    Lundgren, Karin
    Chalmers University of Technology.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Cervenka, Jan
    Cervenka Consulting, Praha.
    Herwig, Andrin
    EPFL, Lausanne.
    Brühwiler, Eugen
    EPFL, Lausanne.
    Thelandersson, Sven
    LTH, Lund.
    Rosell, Ebbe
    Vägverket, Borlänge.
    Structural assessment of concrete railway bridges2008In: Bridge Maintenance, Safety Management, Health Monitoring and Informatics: Proceedings of the Fourth International Conference on Bridge Maintenance, Safety and Management, July 13-17 2008, Seoul, Korea - IABMAS '08 / [ed] Hyun-Moo Koh; Dan G Frangopol, Boca Raton, Fla: Taylor and Francis Group , 2008, p. 3642-3649Conference paper (Refereed)
  • 332.
    Popescu, Cosmin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Northern Research Institute - NORUT, Narvik, Norway.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Blanksvärd, Thomas
    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.
    3D reconstruction of existing concrete bridges using optical methods2019In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 15, no 7, p. 912-924Article in journal (Refereed)
    Abstract [en]

    Routine bridge inspections usually consist of visual observations. These inspections are time-consum-ing and subjective. There is a need to identify new inspection techniques for infrastructure that reducetraffic disturbance, and improve the efficiency and reliability of the acquired data. This study comparedthe performance of three different imaging technologies for the three-dimensional (3D) geometricmodeling of existing structures: terrestrial laser scanning, close-range photogrammetry, and infraredscanning. Each technology was used to assess six existing concrete railway bridges. The technologieswere compared in terms of geometric deviations, visualization capabilities, the level of the inspector’sexperience, and degree of automation. The results suggest that all methods investigated can be usedto create 3D models, however, with different level of completeness. Measurements such as spanlength, deck widths, etc. can be extracted with good accuracy. Although promising, a full off-siteinspection is currently not feasible as some areas of the bridges were difficult to capture mainly dueto restricted access and narrow spaces. Measurements based on terrestrial laser scanning were closerto the reality compared to photogrammetry and infrared scanning. The study indicates the no specialtraining is needed for photogrammetry and infrared scanning to generate a 3D geometric model.

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  • 333.
    Popescu, Cosmin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Sintef, Narvik, Norway.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Blanksvärd, Thomas
    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.
    A comparison between laser scanning, photogrammetry and infrared scanning to create 3D digital models of existing concrete bridges2020In: 1st IABSE Online Symposium 2020: Synergy of Culture and Civil Engineering - History and Challenges / [ed] Jan Bien; Jan Biliszczuk; Pawel Hawryszkow; Maciej Hildebrand; Marta Knawa-Hawryszkow; Krzysztof Sadowski, International Association for Bridge and Structural Engineering (IABSE) , 2020, p. 1101-1108Conference paper (Refereed)
    Abstract [en]

    Routine bridge inspections usually consist of visual observations. These inspections are time-consuming and subjective. There is a need to identify new inspection techniques for infrastructure that reduce traffic disturbance, and improve the efficiency and reliability of the acquired data. This study compared the performance of three different imaging technologies for the three-dimensional (3D) geometric modelling of existing structures: Terrestrial laser scanning, close-range photogrammetry, and infrared scanning. Each technology was used to assess six existing concrete railway bridges. The technologies were compared in terms of geometric deviations, visualization capabilities, the level of the inspector's experience, and degree of automation. The results suggest that all methods investigated can be used to create 3D models, however, with different level of completeness.

  • 334.
    Popescu, Cosmin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. SINTEF Narvik, 8504 Narvik, Norway.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Invator AB, Box 1093, 181 22 Lidingö, Sweden.
    Blanksvärd, Thomas
    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.
    Remote bridge inspection using optical methods2022In: 24th NCR Symposium Proceedings / [ed] Johan Silfwerbrand, Nordic Concrete Federation , 2022Conference paper (Refereed)
    Abstract [en]

    Routine bridge inspections usually consist of visual observations. These inspections are timeconsuming and subjective. There is a need to identify new inspection techniques for infrastructure that reduce traffic disturbance, and improve the efficiency and reliability of the acquired data. This study compared the performance of three different imaging technologies for the threedimensional (3D) geometric modelling of existing structures: terrestrial laser scanning, closerange photogrammetry, and infrared scanning. Each technology was used to assess six existing concrete railway bridges. The results suggest that all methods investigated can be used to create 3D models, however, with different level of completeness.

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    fulltext
  • 335.
    Popescu, Cosmin
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Blanksvärd, Thomas
    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.
    Jimenez, Alexander
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Industrilized and sustainable construction.
    Crabtree Gärdin, David
    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.
    Carolin, Anders
    Trafikverket, Luleå, Sweden.
    Optical methods and wireless sensors for monitoring of bridges2019In: IABSE Symposium 2019: Towards a Resilient Built Environment - Risk and Asset Management, International Association for Bridge and Structural Engineering (IABSE) , 2019, p. 1191-1198Conference paper (Refereed)
    Abstract [en]

    Six railway bridges have been scanned using infrared scanning (IR), close range photogrammetry (CRP) and terrestrial laser scanning (TRS) to reconstruct point clouds and evaluate the potential ofthe technologies for building information modelling (BIM)- and assessment purposes. The resultsmay also help to improve bridge inspection routines. This is done by evaluating the accuracy and quality of the point clouds, time consumption, safety and traffic disturbance. Wireless Monitoring has been used in a demonstration project in Sweden. It consists of a base station and nodes. The base station receives signals from the node antennas and transmits thesignals to the cloud. The nodes are equipped with strain gauges, crack opening devices, temperature sensors or other suitable sensors for the investigation purpose. Results from the methods and conclusions regarding further use will be presented

  • 336.
    Puurula, Arto
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Enochsson, Ola
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sas, Gabriel
    NORUT, Narvik, NO 8517, Norway.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Ohlsson, Ulf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Bernspång, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Carolin, Anders
    Trafikverket, SE 97 125 Luleå, Sweden.
    Paulsson, Björn
    Trafikverket, SE 78 189 Borlänge, Sweden.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Assessment of the Strengthening of an RC Railway Bridge with CFRP utilizing a Full-Scale Failure Test and Finite-Element Analysis2015In: Journal of Structural Engineering, ISSN 0733-9445, E-ISSN 1943-541X, Vol. 141, no 1, article id D4014008Article in journal (Refereed)
    Abstract [en]

    A finite element (FE) model was calibrated using the data obtained from a full-scale test to failure of a 50 year old reinforced concrete (RC) railway bridge. The model was then used to assess the effectiveness of various strengthening schemes to increase the loadcarrying capacity of the bridge. The bridge was a two-span continuous single-track trough bridge with a total length of 30 m, situated in Örnsköldsvik in northern Sweden. It was tested in situ as the bridge had been closed following the construction of a new section of the Railway line. The test was planned to evaluate and calibrate models to predict the load-carrying capacity of the bridge and assess the strengthening schemes originally developed by the European research project called Sustainable bridges. The objective of the test was to investigate shear failure, rather than bending failure for which good calibrated models are already available. To that end, the bridge was strengthened in flexure before the test using near-surface mounted square section carbon fiber reinforced polymer (CFRP) bars. The ultimate failure mechanism turned into an interesting combination of bending, shear, torsion, and bond failures at an applied load of 11.7 MN (2,630 kips). A computer model was developed using specialized software to represent the response of the bridge during the test. It was calibrated using data from the test and was then used to calculate the actual capacity of the bridge in terms of train loading using the current Swedish load model which specifies a 330 kN (74 kips) axle weight. These calculations show that the unstrengthened bridge could sustain a load 4.7 times greater than the current load requirements (which is over six times the original design loading), whilst the strengthened bridge could sustain a load 6.5 times greater than currently required. Comparisons are also made with calculations using codes from Canada, Europe, and the United States.

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  • 337.
    Puurula, Arto
    et al.
    Savonia University of Applied Sciences, Kuopia, Finland.
    Enochsson, Ola
    Bodens kommun, Sverige.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Ohlsson, Ulf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Bernspång, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Täljsten, Björn
    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.
    3D non-linear FE analysis of a full scale test to failure of a RC Railway Bridge strengthened with carbon fibre bars2016In: IABSE CONGRESS, STOCKHOLM, 2016: Challenges in Design and Construction of an Innovativeand Sustainable Built Environment / [ed] Lennart Elfgren, Johan Jonsson, Mats Karlsson, Lahja Rydberg-Forssbeck and Britt Sigfrid, CH - 8093 Zürich, Switzerland: International Association for Bridge and Structural Engineering, 2016, p. 2527-2535Conference paper (Refereed)
    Abstract [en]

    At a full scale loading test to failure a 50 year old concrete railway trough bridge in Örnsköldsvik, in northern Sweden was tested to failure. The test was a part of the European Research Project “Sustainable Bridges” regarding assessment and strengthening of existing bridges. In the projectnew calculation methods were developed to capture the behaviour of the bridge during increasing load. The bridge was strengthened in bending with rods of Carbon Fiber Reinforced Polymer (CFRP) before the loading test. Failure was reached for an applied load of 11.7 MN by pulling a steel beam placed in the middle of one of the two spans downwards. The achieved failure was a combination of bond, shear, torsion and bending. The developed model, a 3D -non-linear finiteelement (FE) model with discrete reinforcement, gave accurate accounts of the response of thebridge. The FE calculations show the effect of the strengthening with CFRP and even the effect of the epoxy when using the Near Surface Mounted Reinforcement (NSMR) strengthening method.

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  • 338.
    Puurula, Arto
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Enochsson, Ola
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Load carrying capacity of a RC Bridge in Örnsköldsvik, Sweden2011In: Nordic Concrete Research: Proceedings of the XXI Nordic Concrete Research Symposium, Hämeenlinna, Finland 2011, Oslo: The Nordic Concrete Federation , 2011, p. 29-32Conference paper (Refereed)
  • 339. Puurula, Arto
    et al.
    Enochsson, Ola
    Thun, Håkan
    Nordin, Håkan
    Täljsten, Björn
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Paulsson, Björn
    Banverket.
    Olofsson, Jan
    Skanska.
    Full-scale test to failure of a strengthened reinforced concrete bridge: calibration of assessment models for load-bearing capacities of existing bridges2008In: Nordic Concrete Research, ISSN 0800-6377, no 2, p. 131-142Article in journal (Refereed)
    Abstract [en]

    A reinforced concrete railway trough bridge has been strengthened and loaded to failure. The aim was to test and calibrate methods developed in the European Research Project "Sustainable Bridges" regarding: (a) condition appraisal and inspection, (b) load carrying capacity analysis, (c) monitoring and (d) strengthening of existing bridges. The tested methods proved to be useful and to give accurate predictions. A failure in combined shear, bending and torsion was reached for an applied mid span load of 11,7 MN. This was well predicted by enhanced methods but 20 to 50 % higher than ultimate load evaluated according to predictions based on common codes and models.

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  • 340. Puurula, Arto
    et al.
    Enochsson, Ola
    Thun, Håkan
    Täljsten, Björn
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Olofsson, Jan
    Skanska Teknik, Göteborg.
    Paulsson, Björn
    Banverket.
    Test of a concrete bridge in Sweden: I. Assessment methods2008In: Bridge Maintenance, Safety, Management, Health Monitoring and Informatics: Proceedings of the fourth International Conference on Bridge Maintenance, Safety and Management, Seoul, Korea, 13-17 July 2008 / [ed] Hyun-Moo Koh; Dan M Frangopol, Boca Raton, Fla: Taylor and Francis Group , 2008, p. 3385-3592Conference paper (Refereed)
  • 341.
    Puurula, Arto M.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering. Structural Engineering, Savonia University of Applied Sciences, P.O. Box 88 (Opistotie 2), FI-70101 Kuopio, Finland.
    Enochsson, Ola
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Sas, Gabriel
    Department of Infrastructure Structures and Materials, NORUT Narvik, Lodve Langes gt. 2, P.O. Box 250, N-8504 Narvik, Norway.
    Blanksvärd, Thomas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Ohlsson, Ulf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Bernspång, Lars
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Täljsten, Björn
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Loading to failure and 3D nonlinear FE modelling of a strengthened RC bridge2014In: Structure and Infrastructure Engineering, ISSN 1573-2479, E-ISSN 1744-8980, Vol. 10, no 12, p. 1606-1619Article in journal (Refereed)
    Abstract [en]

    A reinforced concrete railway trough bridge in Örnsköldsvik, Sweden, was strengthened in bending with rods of carbon-fibre-reinforced polymer and loaded to failure. The aim was to test and calibrate methods developed in the European Research Project ‘Sustainable Bridges’ regarding assessment and strengthening of existing bridges. A steel beam was placed in the middle of one of the two spans and was pulled downwards. Failure was reached at an applied load of 11.7 MN. It was initiated by a bond failure caused by a combined action of shear, torsion as well as bending after yielding in the longitudinal steel reinforcement and the stirrups. The bond failure led to a redistribution of the internal forces from the tensile reinforcement to the stirrups, causing the final failure. The computer models developed to simulate the loading process were improved step by step from linear shell models to more detailed models. The most developed model, a three-dimensional nonlinear finite element model with discrete reinforcement, gave accurate accounts of the response of the bridge.

  • 342.
    Puurula, Arto M.
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. Savonia University of Applied Sciences, Kuopio, Finland.
    Enochsson, Ola
    Trafikverket.
    Sas, Gabriel
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Täljsten, Björn
    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.
    Failure of a RC Bridge initiated by debonding: 3-D Non-Linear Finite Element Analysis of Near Surface Mounted Fibre Reinforced Polymer Bars (NSM FRPB)2021Report (Refereed)
    Abstract [en]

    The bond failure is studied of a reinforced concrete trough bridge strengthened with near surface mounted reinforcement of carbon fibre reinforced polymer (CFRP) bars. The bars were embedded in epoxy resin in pre-sawed groves in the soffit of the bridge edge beams. The failure was modelled with 3D nonlinear finite elements, and it was possible to study the process from initiation to final collapse. A local bond failure in the interface between the concrete and the epoxy resin initiated a redistribution of forces in the bridge leading to yielding in the longitudinal and vertical steel reinforcement, rupture of stirrups and finally a full failure of the bridge. The bridge was a 50-year-old typical concrete railway trough bridge in Örnsköldsvik, in northern Sweden. It was going to be dismantled due to a relocation of the railway line. The aim of the loading test was to get detailed information of the bridge behaviour all the way up to the final failure. The test was a part of the European Research Project “Sustainable Bridges” regarding assessment and strengthening of existing bridges. The bridge was strengthened in bending before the loading test to avoid an uninteresting flexural failure. Failure was reached for an applied load of 11,7 MN by pulling downwards a steel beam placed in the middle of one of the two spans.  The FE calculations presented here show the effect of the strengthening with CFRP, the effect of the epoxy when using the Near Surface Mounted Reinforcement (NSMR) strengthening method and the high load-carrying capacity of this bridge type

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  • 343.
    Qin, Xiao-Chuan
    et al.
    School of Civil Engineering, Southeast University.
    Meng, Shao-Ping
    School of Civil Engineering, Southeast University.
    Cao, Da-Fu
    School of Civil Science and Engineering, Yangzhou University.
    Tu, Yong-Ming
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Sabourova, Natalia
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Grip, Niklas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Ohlsson, Ulf
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Blanksvärd, Thomas
    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.
    Evaluation of freeze-thaw damage on concrete material and prestressed concrete specimens2016In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 125, p. 892-904Article in journal (Refereed)
    Abstract [en]

    The pore structure of the hardened concrete and the microscopic changes of a few selected pores throughout the freeze-thaw test were investigated by a method combining RapidAir and digital metalloscope. Traditional tests were also performed to evaluate the macroscopic change caused by freeze-thaw cycles (FTCs). The investigation shows that the concrete material, of which the spacing factor is 0.405 mm and the air content is 2.38%, can still withstand more than 300 FTCs. Severe microscopic damages occurred after approximately 200 FTCs and the freeze-thaw damage were gradually aggravated afterwards. Prestress forces have a remarkable impact on the failure pattern under FTCs. It was further found that the compressive strength as an indicator is more reliable than the relative dynamic modulus of elasticity in evaluating the freeze-thaw damage on concrete material. In addition, the test and analysis show that the measured prestress losses of bonded specimen are larger than that of unbounded specimen under the attack of FTCs due to the duct grouting effect. The ultimate freeze-thaw prestress loss is about 5% of σconσcon for both the bonded and unbonded specimens because the grouting cement paste will eventually be completely destroyed.

  • 344.
    Richard, Benjamin
    et al.
    University Paris-Est, Laboratoire Central des Ponts et Chaussées, 58 bd Lefebvre, 75732 Paris cedex, France.
    Epaillard, Sébastien
    University Paris-Est, Laboratoire Central des Ponts et Chaussées, 58 bd Lefebvre, 75732 Paris cedex, France.
    Cremona, Chrisitian
    Directorate for Research and Innovation, Ministry of Ecology, Energy, Sustainable Development and Sea, Tour Voltaire, 92055 La Défense, France.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Adelaide, Lucas
    University Paris-Est, Laboratoire Central des Ponts et Chaussées, 58 bd Lefebvre, 75732 Paris cedex, France.
    Nonlinear finite element analysis of a 50 years old reinforced concrete trough bridge2010In: Engineering structures, ISSN 0141-0296, E-ISSN 1873-7323, Vol. 32, no 12, p. 3899-3910Article in journal (Refereed)
    Abstract [en]

    In this paper, a nonlinear finite element model of a full scale bridge (Örnsköldsvik bridge, Sweden) is presented in connection with load tests. In order to quantify the carrying capacity of the bridge, a collapse load test was performed within the European Union founded project ‘‘Sustainable Bridges - Assessment for Future Traffic Demands and Longer Lives''. The finite element model introduces new constitutive material models. Four materials are in particular modelled in accordance with the bridge characteristics: concrete, steel reinforcement bars, CFRP bars and steel/concrete interface. The concrete is described by a damage mechanics based model developed within the framework of the irreversible processes thermodynamics. This ensures consistency with respect to the well known physics principles (conservation and evolution). The steel reinforcement bars and the CFRP bars are modelled using classical elasto-plastic constitutive laws with an isotropic hardening. The steel/concrete interface is developed in such a way that it may include corrosion. The numerical results are very close to the experimental measurements. Based on that finite element model, the influence of local degradation due to uniform corrosion is then studied. Two effects are considered for this purpose: steel cross section reductions and bond strength variations at the steel/concrete interface. Although these latter results remain informative due to the lack of documented data regarding the corrosion content in the bridge, they allow corroborating experimental measurements published in the literature.

  • 345. Ronin, Vladimir
    et al.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Energetically Modified Cement (EMC): Performance Mechanism2002Report (Other academic)
    Abstract [en]

    Energetically Modified Cements, EMC, made of intensively milled cement (50%) and fillers (50%) of quartz or fly ash have been compared to blends of Ordinary Portland Cement, OPC, and fillers. The EMCs have better properties than other blends and are comparable to unblended OPC.

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  • 346.
    Ronin, Vladimir
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering. EMC Cement B.V., Alvägen 33, SE-973 32 Luleå, Sweden.
    Emborg, Mats
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Self-Healing Performance and Microstructure Aspects of Concrete Using Energetically Modified Cement with a High Volume of Pozzolans2014In: Nordic Concrete Research, ISSN 0800-6377, Vol. 51, p. 131-144Article in journal (Refereed)
    Abstract [en]

    Self-healing can increase the lifetime and durability of concrete structures. The self-healing properties of concrete made with Energetically Modified Cement (EMC), which has a pozzolan content of up to 70%, have been investigated. In such concretes, pozzolanic reactions within the cement cause the gradual formation of fresh C-S-H gel, which seals cracks as they form. The self-healing of small EMC concrete samples was tested in a laboratory, and field observations of an EMC concrete highway pavement were made. The EMC concrete exhibited fewer cracks than conventional concrete, and was observed to self-heal cracks with widths of up to 0.2 mm.

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    fulltext
  • 347.
    Ronin, Vladimir
    et al.
    EMC Development.
    Jonasson, Jan-Erik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    "Greener" concrete with new technology2004In: Swedish Research for Sustainability, ISSN 1650-576X, Vol. 1, no 1, p. 8-9Article in journal (Other (popular science, discussion, etc.))
    Abstract [en]

    Today a lot of attempts are made by technologists to make lower environmental impact of cement and concrete. By modifying our existing cement types with differnt types of fillers and additives, carbon dioxide emissions and energy use can be further reduced and "greener" cement and concrete can be produced.

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    fulltext
  • 348. Ronin, Vladimir
    et al.
    Jonasson, Jan-Erik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    "Grönare" betong med ny teknik2004In: Miljöforskning : Formas tidning : för ett uthålligt samhälle, ISSN 1650-4925, no 3, p. 16-17Article in journal (Other (popular science, discussion, etc.))
  • 349.
    Ronin, Vladimir
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering. EMC Cement B.V..
    Jonasson, Jan-Erik
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Elfgren, Lennart
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Construction Engineering.
    Self-Healing Concrete: Results with Energetically Modified Cement (EMC)2014In: Nordic Concrete Research, ISSN 0800-6377, Vol. 50, p. 57-60Article in journal (Refereed)
    Abstract [en]

    Energetically Modified cement (EMC) containing up to 70 % of pozzolans have been tested to have the ability to deliver long term pozzolanic reactions (calcium oxide + wateer + silicon dioxide) leading to the formation of additional amounts of C-H-S gel. This can fill voids and cracks of widths up to 0,2 mm, up to twice the crack width that usually can be healed. EMC is Portland cement mechanically activated in a process with a pozzolan, silica sand or blast furnace slag. The process was discovered 1992 at Luleå University of Technology and has been further developed since then.

  • 350.
    Sabourova, Natalia
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Duvnjak, I.
    University of Zagreb, Zagreb, Croatia..
    Grip, Niklas
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Mathematical Science.
    Damjanovic, D.
    University of Zagreb, Zagreb, Croatia..
    Tu, Yongming
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering. School of Civil Engineering, Southeast University, Nanjing, China.
    Popescu, Cosmin
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Structural and Fire Engineering.
    Ohlsson, Ulf
    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.
    Detection of sparse damages in plates2020In: IABSE Symposium, Wroclaw 2020: Synergy of Culture and Civil Engineering – History and Challenges / [ed] Jan Bień, Jan Biliszczuk, Paweł Hawryszków, Maciej Hildebrand, Marta Knawa-Hawryszków, Krzysztof Sadowski, Zürich: International Association For Bridge And Structural Engineering (IABSE) , 2020, p. 1141-1148Conference paper (Refereed)
    Abstract [en]

    Structural damage is often a spatially sparse phenomenon, i.e. it occurs only in a small part of the structure. This property of damage has not been utilized in the field of structural damage identification until quite recently, when the sparsity-based regularization developed in compressed sensing problems found its application in this field. In this paper we consider classical sensitivity-based finite element model updating combined with a regularization technique appropriate for the expected type of sparse damage. The validity of the proposed methods is demonstrated using simulations on a bridge. The pros and cons of these methods are discussed.

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    Sabourova
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