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  • 1.
    Ahlenius, Elisabeth
    KTH, Superseded Departments, Structural Engineering.
    Explosionslaster och infrastrukturkonstruktioner: risker, värderingar och kostnader1999Licentiate thesis, monograph (Other scientific)
  • 2.
    Alavizadeh-Farhang, Ali
    KTH, Superseded Departments, Structural Engineering.
    Concrete structures subjected to combined mechanical and thermal loading2000Doctoral thesis, monograph (Other scientific)
  • 3.
    Alavizadeh-Farhang, Ali
    KTH, Superseded Departments, Structural Engineering.
    Plain and steel fibre reinforced concrete beams subjected to combined mechanical and thermal loading1998Licentiate thesis, monograph (Other scientific)
  • 4.
    Ansell, Anders
    KTH, Superseded Departments, Structural Engineering.
    Dynamically loaded rock reinforcement1999Doctoral thesis, monograph (Other scientific)
  • 5.
    Ansell, Anders
    KTH, Superseded Departments, Structural Engineering.
    Töjningsmätning vintertid vid tågpassage över gamla Lidingöbron2004Report (Other academic)
  • 6.
    Ansell, Anders
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Kalinowski, Mariusz
    Undersökning av takputs i Naturhistoriska Riksmuséets lokaler2004Report (Other academic)
  • 7.
    Appelqvist, Ingert
    KTH, Superseded Departments, Structural Engineering.
    Sammanbyggnad: datastrukturer och utveckling av ett IT-stöd för byggprocessen1997Licentiate thesis, monograph (Other scientific)
  • 8.
    Ay, Lutfi
    KTH, Superseded Departments, Structural Engineering.
    Using prestressed steel fiber reinforced high performance concrete in the industrilization of bridge structures1999Licentiate thesis, monograph (Other scientific)
  • 9.
    Battini, Jean-Marc
    KTH, Superseded Departments, Structural Engineering.
    Co-rotational beam elements in instability problems2002Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The purpose of the work presented in this thesis is to implement co-rotational beam elements and branch-switching procedures in order to analyse elastic and elastoplasticinstability problems. For the 2D beam elements, the co-rotational framework is taken from Crisfield [23]. The main objective is to compare three different local elasto-plastic elements. The 3D co-rotational formulation is based on the work of Pacoste and Eriksson [73],with new items concerning the parameterisation of the finite rotations, the definitionof the local frame, the inclusion of warping effects through the introduction of aseventh nodal degree of freedom and the consideration of rigid links. Differenttypes of local formulations are considered, including or not warping effects. It isshown that at least some degree of non-linearity must be introduced in the localstrain definition in order to obtain correct results for certain classes of problems. Within the present approach any cross-section can be modelled, and particularly, the centroid and shear center are not necessarily coincident.Plasticity is introduced via a von Mises material with isotropic hardening. Numericalintegration over the cross-section is performed. At each integration point, theconstitutive equations are solved by including interaction between the normal andshear stresses. Concerning instabilities, a new numerical method for the direct computation of elasticcritical points is proposed. This is based on a minimal augmentation procedure asdeveloped by Eriksson [32–34]. In elasto-plasticity, a literature survey, mainly concernedwith theoretical aspects is first presented. The objective is to get a completecomprehension of the phenomena and to give a basis for the two branch-switchingprocedures presented in this thesis.A large number of examples are used in order to assess the performances of the elements and the path-following procedures.

  • 10.
    Battini, Jean-Marc
    KTH, Superseded Departments, Structural Engineering.
    Plastic instability analysis of plane frames using a co-rotational approach1999Licentiate thesis, monograph (Other scientific)
  • 11.
    Battini, Jean-Marc
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Pacoste, Costin
    KTH, Superseded Departments, Structural Engineering.
    Elements poutres co-rotationels avec gauchissement2001In: Proceedings CSMA 5éme colloque national en calcul des structures, Giens, 2001Conference paper (Refereed)
  • 12.
    Battini, Jean-Marc
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Pacoste, Costin
    KTH, Superseded Departments, Structural Engineering.
    Eriksson, Anders
    KTH, Superseded Departments, Structural Engineering.
    Improved minimal augmentation procedure for the direct computation of critical points2003In: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 192, no 16-18, p. 2169-2185Article in journal (Refereed)
    Abstract [en]

    This paper presents a new numerical procedure for the direct computation of critical points for elastic beam structures undergoing large displacements and rotations. Compared to the approach described by Wriggers et al. [Comput. Methods Appl. Mech. Engrg. 70 (1988) 329; Int. J. Numer. Methods Engrg. 30 (1990) 1551, two main modifications are introduced. First, following Eriksson [Comput. Methods Appl. Mech. Engrg. 114 (1994) 77; Comput. Methods Appl. Mech. Engrg. 156 (1998) 45; Comput. Methods Appl. Mech. Engrg. 179 (1999) 265; Int. J. Struct. Stability Dynam. l(l) (2001)], the condition of criticality is expressed by a scalar equation instead of a vectorial one. Next, the present procedure does not use exclusively the extended system obtained from the equilibrium equations and the criticality condition, but also introduces intermediate iterations based purely on equilibrium equations under load or displacement control, Eight numerical examples, presenting bifurcation and limit points, are used in order to compare the performances of this new method and the one presented in [Comput. Methods Appl. Mech. Engrg. 70 (1988) 329; Int. J. Numer. Methods Engrg. 30 (1990) 155].

  • 13.
    Bayoglu Flener, Esra
    KTH, Superseded Departments, Structural Engineering.
    Field Testing of a Long-span Arch Steel Culvert Railway Bridge over Skivarpsån, Sweden: Part II2004Report (Refereed)
  • 14.
    Billberg, Peter
    KTH, Superseded Departments, Structural Engineering.
    Some rheology aspects on fine mortar part of concrete1999Licentiate thesis, monograph (Other scientific)
  • 15.
    Broms, Carl Erik
    KTH, Superseded Departments, Structural Engineering.
    Elimination of flat plate punching failure mode2000In: ACI Structural Journal, ISSN 0889-3241, E-ISSN 1944-7361, Vol. 97, no 1, p. 94-101Article in journal (Refereed)
    Abstract [en]

    A design concept that eliminates the punching failure mode of flat plates is verified by testing, and design recommendations are given. Only standard reinforced is used, which is so easy to fabricate and rapid to install that the solution should be suitable as standard practice ordinary flat plates as well as for such extremes applications as air-raid shelters. The system provides excellent safely against progressive collapse of flat plate buildings, a basic requirements that seems to be overlooked in many current concrete codes. The provisions of the ACI Code 318-95 for two-way shear capacity of slabs are found unsafe for critical sections outside shear reinforcement and presumably also around large columns.

  • 16.
    Broms, Carl Erik
    KTH, Superseded Departments, Structural Engineering.
    Punching of flat plates: a question of concrete properties in biaxial compression and size effect 1990In: ACI Structural Journal, ISSN 0889-3241, E-ISSN 1944-7361, Vol. 87, no 3, p. 292-304Article in journal (Refereed)
    Abstract [en]

    The paper presents a design method to predict the punching strength and deflection of flat plates at interior columns. Failure is assumed to occur when the compression zone of the slab in the vicinity of the column is distressed by either a high radial compression stress or by a high tangential compression strain. Size effects and the effect of increasing concrete brittleness with increasing strength are both considered. The method shows excellent agreement with results from punching tests reported in the literature, with conditions ranging from ductile flexural failures to brittle punching failures, from small test specimens to a full-sized structure, from symmetrical to unsymmetrical loadings, and from low to high concrete strengths and reinforcement ratios.

  • 17.
    Broms, Carl Erik
    KTH, Superseded Departments, Structural Engineering.
    Shear reinforcement for deflection ductility of flat plates1990In: ACI Structural Journal, ISSN 0889-3241, E-ISSN 1944-7361, Vol. 87, no 6, p. 696-705Article in journal (Refereed)
    Abstract [en]

    The deflection ductility of flat plates with different types of shear reinforcement is tested. Excellent performance is achieved with a combination of bent bars and stirrups, even at reinforcement ratios exceeding 0.75ρb. Code requirements for flat plates are critically reviewed and design recommendations are given for the bent bar/stirrup reinforcement arrangement.

  • 18.
    Edlund, Stefan
    KTH, Superseded Departments, Structural Engineering.
    Arbitrary thin-walled cross sections: theory and computer implementation1997Licentiate thesis, monograph (Other scientific)
  • 19.
    Edlund, Stefan
    KTH, Superseded Departments, Structural Engineering.
    Buckling of T-section beam-columns in aluminium with or without transverse welds2000Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This thesis deals with buckling of T-section beam-columns inaluminium with or without transverse welds. Totally 26 unweldedand 39 transversely welded T-section beam-columns were tested.Five of the welded beams were clamped. All unwelded and therest of the welded beams were simply supported for bending. Thewelding affects the load-carrying capacity of the beam-columns,because it introduces a heat-affected zone with reducedstrength. All beam-columns had the same theoreticalcross-section dimensions. The thickness of the flange and theweb was 6 mm. The depth and the width were 60 mm. Thetheoretical beam lengths were 500, 1020 and 1540 mm,respectively. Tensile tests of both the parent and theheat-affected material were made in order to determine thematerial properties.

    Comparisons were made between the buckling tests and threecodes, the European aluminium code Eurocode 9, the Britishaluminium code BS 8118 and the Swedish steel code BSK. Someinterpretations of the codes had to be made, because the codesare not totally clear when applied on T-sections. Most problemsare related to the fact that the section modulus is not thesame for the two edges. In the interaction formulas, only theedge in compression was considered when the bending momentcapacity was calculated. The chosen interpretation of the codeswas often very conservative when compared with the bucklingtests.

    The general-purpose finite element program Abaqus was usedto develop numerical models of the tested beam-columns. Shellelements were used. The models were calibrated with the resultsfrom the buckling tests. The stress-strain curves used in thefinite element calculations were obtained from the tensiletests. The results of the finite element calculations weresatisfactory. The numerical models could predict the loadcarrying capacity accurate enough. A similar deformed shape ofthe tested and calculated beam-columns was also obtained.

    Different modifications of Eurocode 9 were analysed in orderto improve the results. One modification was that the ultimatestrength of the heat-affected zone was used instead of theyield strength of the parent material whenthe bucklingreduction factors of a welded section were calculated. Thecalculation of the bending moment capacity in the interactionformulas was also modified. The plastic section modulus wasused to calculate the bending moment capacity when the tip ofthe web was in tension. When the bending moment acted in theopposite direction, the calculation of the bending momentcapacity was based on a modified classification of the webelement. The investigation in this thesis indicates thatEurocode 9 is too severe in the classification of thecross-section. The way the bending moment capacity iscalculated for unsymmetric cross-sections in the interactionformulas needs to be further analysed. Tensile failure at thetip of the web was also discussed. This thesis shows that thecodes need to be improved when it concerns unsymmetriccross-sections. Some information how Eurocode 9 can be improvedis given.

    Keywords: Buckling, buckling tests, Eurocode 9, aluminiumbeam-columns, beam-columns, T-sections, finite elementanalysis, transverse welds, codes, unsymmetriccross-sections.

  • 20.
    Eriksson, Anders
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Pacoste, C.
    Element formulation and numerical techniques for stability problems in shells2002In: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 191, no 35, p. 3775-3810Article in journal (Refereed)
    Abstract [en]

    In the context of instability problems in shells or shell like structures, the objective of the present paper is twofold. Primarily, the paper describes how quasi-static, conservative instability problems can be considered in a multi-parametric context, where generalized path-following procedures for augmented equilibrium problems are used as computational tools. These allow systematic treatment of the higher-dimensional solution sets generated under the variations of certain parameters deemed relevant for the given problem. The efficient implementation of the above mentioned procedures requires however, as an essential ingredient, a non-linear finite element which is not only accurate but also inexpensive. To this end, a systematic view on a corotational Total Lagrangian formulation is described. The TRIC element of Argyris and coworkers is slightly modified, and introduced as core element formulation. Special emphasis is given to the alternative methods for treatment of finite three-dimensional rotations, with reference to both the element definition and solution algorithms. Numerical examples verify the element capabilities, and the possibility to completely describe instability phenomena of large, discretized models.

  • 21.
    Forsell, Karin
    KTH, Superseded Departments, Structural Engineering.
    Dynamic analyses of static instability phenomena1997Licentiate thesis, monograph (Other scientific)
  • 22.
    Forsell, Karin
    KTH, Superseded Departments, Structural Engineering.
    Instability analyses of structures under dynamic loads2000Doctoral thesis, monograph (Other scientific)
  • 23.
    Fransson, Håkan
    KTH, Superseded Departments, Structural Engineering.
    Rotation capacity of reinforced high strength concrete beams1997Licentiate thesis, monograph (Other scientific)
  • 24.
    Getachew, Abraham
    KTH, Superseded Departments, Structural Engineering.
    Trafiklaster på broar: Analys av insamlade och Monte Carlo genererade fordonsdata2000Licentiate thesis, monograph (Other academic)
    Abstract [en]

    This thesis begins with the description of background ,aims and goals of the project. Afterwards, a brief explanation of the probability theory and some probabilistic distribution functions that are used in this work are given.Then the concept of structural reliability is explained. Subsequently the meaning of Monte-Carlo simulation technique in relation to this workis described.

    Traffic load models given indifferent codes cannot be used directly for the design of long-span bridges, i.e.bridges with span lengths larger than 200 meters. For the determination of the characteristic load values for such bridges, the Swedish National Road Administration (Vli.gverket) conducted traffic load measurements in five different locations in Sweden.

    All measurement data of course contain errors. Therefore, the collected data from one of the measurement series are investigated in this work. The investigation shows that among the collected data there are vehicles that are registered with unreasonable lengths or/and weights. Totally about 10% of the whole collected data are considered to be inaccurate and should be excluded before further analyses of the vehicle data. About 10%,of the whole collected data, are vehicle dataregistered with one axle. Because of the limited information, these vehicles could not be identified and therefore are not excluded.

    The characteristic and design traffic load values for different queue lengths are calculated using vehicle data both before and after filtration of inaccurate data. The results hows that the influence of inaccurate data is insignificant. The largest difference between characteristic load values calculated before and after filtration of inaccurate data is 3,5%. Comparing the characteristic as well as the design traffic load values with corresponding values according to BRO 94 shows that the code values are considerably higher than the actual values.

    In this work, the Monte-Carlo simulation technique is also used to generate vehicle data. The simulated vehicle data show good agreement with the collected data. Afterwards, the probability distribution functions from the simulated as well as the collected vehicle data are calculated and compared. The result shows that the probability distribution functions agree well specially for grater queue weight values.

  • 25.
    Hassanzadeh, Ghassem
    KTH, Superseded Departments, Structural Engineering.
    Betongplattor på pelare: dimensioneringsmetoder för plattor med icke vidhäftande spännarmering1998Licentiate thesis, monograph (Other scientific)
  • 26.
    Ikäheimonen, Jukka
    KTH, Superseded Departments, Structural Engineering.
    Construction loads on shores and stability of horizontal formworks1997Doctoral thesis, monograph (Other scientific)
  • 27.
    James, Gerard
    KTH, Superseded Departments, Structural Engineering.
    Raising allowable axle loads on railway bridges using simulation and field data2001Licentiate thesis, monograph (Other scientific)
  • 28.
    Johnson, Rickard
    KTH, Superseded Departments, Structural Engineering.
    Progression of the dynamic properties of large suspension bridges during construction: a case study of the Höga kusten bridge1999Licentiate thesis, comprehensive summary (Other scientific)
  • 29.
    Karawajczyk, Eva
    KTH, Superseded Departments, Structural Engineering.
    Finite element simulations of integral bridge behaviour2001Doctoral thesis, monograph (Other scientific)
  • 30.
    Karawajczyk, Ewa
    KTH, Superseded Departments, Structural Engineering.
    Finite element approach to the mechanics of track-deck systems1997Licentiate thesis, monograph (Other scientific)
  • 31.
    Karoumi, Raid
    KTH, Superseded Departments, Structural Engineering.
    Response of cable-stayed and suspension bridges to moving vehicles: Analysis methods and practical modeling techniques1998Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This thesis presents a state-of-the-art-review and twodifferent approaches for solving the moving load problem ofcable-stayed and suspension bridges.

    The first approach uses a simplified analysis method tostudy the dynamic response of simple cable-stayed bridgemodels. The bridge is idealized as a Bernoulli-Euler beam onelastic supports with varying support stiffness. To solve theequation of motion of the bridge, the finite difference methodand the mode superposition technique are used.

    The second approach is based on the nonlinear finite elementmethod and is used to study the response of more realisticcable-stayed and suspension bridge models considering exactcable behavior and nonlinear geometric effects. The cables aremodeled using a two-node catenary cable element derived using"exact" analytical expressions for the elastic catenary. Twomethods for evaluating the dynamic response are presented. Thefirst for evaluating the linear traffic load response using themode superposition technique and the deformed dead load tangentstiffness matrix, and the second for the nonlinear traffic loadresponse using the Newton-Newmark algorithm.

    The implemented programs have been verified by comparinganalysis results with those found in the literature and withresults obtained using a commercial finite element code.Several numerical examples are presented including one for theGreat Belt suspension bridge in Denmark. Parametric studieshave been conducted to investigate the effect of, among others,bridge damping, bridge-vehicle interaction, cables vibration,road surface roughness, vehicle speed, and tuned mass dampers.From the numerical study, it was concluded that road surfaceroughness has great influence on the dynamic response andshould always be considered. It was also found that utilizingthe dead load tangent stiffness matrix, linear dynamic trafficload analysis give sufficiently accurate results from theengineering point of view.

  • 32.
    Karoumi, Raid
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Darholm, Thomas
    Sundquist, Håkan
    KTH, Superseded Departments, Structural Engineering.
    Betongbågen till Svinesundsbron: en teknisk utmaning för byggare, konstruktörer och ägare2004In: Betong, ISSN 1101-9190, no 6Article in journal (Other academic)
  • 33.
    Karoumi, Raid
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Wiberg, Johan
    KTH, Superseded Departments, Structural Engineering.
    Olofsson, Pär
    Trafikverket.
    Monitoring traffic loads and traffic load effects on the New Årstaberg Railway Bridge2004Conference paper (Refereed)
  • 34.
    Luo, Yunhua
    KTH, Superseded Departments, Structural Engineering.
    On some finite element formulations in structural mechanics1998Doctoral thesis, monograph (Other scientific)
  • 35.
    Löfsjögård, Malin
    KTH, Superseded Departments, Structural Engineering.
    Functional properties of concrete roads: general interrelationships and studies on pavement brightness and sawcutting sawcutting times for joints2000Licentiate thesis, monograph (Other scientific)
  • 36. Mohammadi Mohaghegh, Ali
    et al.
    Silfwerbrand, Johan
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering. KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges. KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures. KTH, Superseded Departments (pre-2005), Structural Engineering.
    Shear Behaviour of High-Performance Basalt Fibre Concrete – Part I: Laboratory Shear Tests on Beams with Macro Fibres and BarsIn: Article in journal (Refereed)
  • 37. Mohammadi Mohaghegh, Ali
    et al.
    Silfwerbrand, Johan
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering. KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges. KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures. KTH, Superseded Departments (pre-2005), Structural Engineering.
    Årskog, Vemund
    Shear Behaviour of High-Performance Basalt Fibre Concrete – Part II: Laboratory Punching Shear Tests on Small Slabs with Macro Fibres without BarsIn: Structural Concrete, ISSN 1464-4177, E-ISSN 1751-7648Article in journal (Refereed)
  • 38. Muravin, Gregory
    et al.
    Sundquist, Håkan
    KTH, Superseded Departments, Structural Engineering.
    Österberg, Elena
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Structural Engineering and Bridges.
    Revealing of age-related deterioration of prestressed reinforced concrete containments in   nuclear power plants - Requirements and NDT methods2004In: 4th International Conference on NDE in relation to structural integrity for nuclear and pressurised components, 2004Conference paper (Refereed)
  • 39.
    Nilsson, Ulf
    KTH, Superseded Departments, Structural Engineering.
    Load bearing capacity of steel fibre reinforced shotcrete linings2000Licentiate thesis, comprehensive summary (Other scientific)
  • 40.
    Pacoste, Costin
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Battini, Jean-Marc
    KTH, Superseded Departments, Structural Engineering.
    Calcul des chemins d'équilibres post-critiques2001In: Proceedings CSMA 5éme colloque national en calcul des structures, Giens, 2001Conference paper (Refereed)
  • 41.
    Pacoste, Costin
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Battini, Jean-Marc
    KTH, Superseded Departments, Structural Engineering.
    Eriksson, Anders
    KTH, Superseded Departments, Structural Engineering.
    Parameterisation of rotations in co-rotational elements2000In: Proceedings Euromech 2000, Metz / [ed] Aeby-Gautier, E. Clavel, M. Dunne, F, Les Ulis: EDP Sciences , 2000Conference paper (Refereed)
    Abstract [en]

    This paper presents some theoretical aspects related to the parameterisation of finite 3D rotations in the formulation of co-rotational beam and shell elements. In this context, the term "co-rotational" means that the motion of the element is decomposed into a rigid body motion followed by a pure deformation in the local coordinate system which continuously translates and rotates with the element.

  • 42.
    Paulsson, Jonatan
    KTH, Superseded Departments, Structural Engineering.
    Effects of repairs on the remaining life of concrete bridge decks1997Licentiate thesis, monograph (Other scientific)
  • 43.
    Paulsson-Tralla, Johatan
    KTH, Superseded Departments, Structural Engineering.
    Service life of repaired concrete bridge decks1999Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Pre-mature deterioration of reinforced concrete causesproblems world-wide and the search for reliable cost effectiveand environmental friendly repairs is intense. The service lifeof the repaired structure is important in order to establishthe annual cost and environmental impact for differentalternatives. This doctoral thesis focuses on the service lifeof concrete bridge decks repaired with bonded concreteoverlays. The approach was broad and based on the performanceof a number of bridge decks after approximately ten years inservice. The main aims were to establish the overall servicelife and to improve the design where improvements were needed.Efforts have been made to make the repairs as robust aspossible and the crucial production stage is always considered.The following parameters were investigated:

        Wear and rutting

        Bond strength and extent and cause of cracks

        Relative humidity and temperature in the deck

        Freeze-thaw resistance and number of freeze-thawcycles

        Concrete cover and service life criterion with respect tochloride initiated corrosion

        Service life predictions using moving boundarytheory

        Chloride concentrations in de-icing water and in thesurfaces of concrete overlays

        Absorption of water and chloride ions due to capillarysuction of de-icing water

        Chloride ingress in solid and cracked parts of bondedconcrete overlays

    The wear and rutting were found to be limited. The bondbetween new and old concrete was unaltered or increased afterten years in service. The cracking on the overlays wasgenerally limited. The main cracking causes were insufficientcuring and reflective cracking due to construction joints (coldcasting joints) in the old bridge deck. The cracks can beavoided or made non-hazardous with respect to corrosion andfreeze-thaw damages with simple measures.

    The chloride ingress was low in solid and limited in crackedparts of the overlay. Samples of concrete, snow, slush andwater were taken from the overlay during two years to quantifythe chloride concentrations and their variations. The chlorideconcentration interacted with the weather, the local climateand the salt-spreading procedures. The chloride content in theoverlays was affected to at least 10 mm from the surface.

    The relative humidity in the overlay was stable and low atapproximately 20 mm from the wear surface. The number of(salt)-freeze-thaw cycles was high. The thickness of theoverlays was found to be fairly normal distributed and this wasused in the service life predictions.

    The moving boundary method is suitable to predict theingress of a chloride threshold value. The method is easy touse with a probabilistic approach and simple and cheap toupdate and no parameters have to be guessed. Numerical methodswere also used and the influence of various surfaceconcentrations was investigated. The transport of chloride ionsinto cracked concrete was treated with a two dimensional modeland the influence of crack depth was found to be limited.

    Both conventional capillary absorption tests and cyclicwetting and drying test out-doors were conducted on matureconcrete cast and aged in-situ. The conclusion was thatcapillary suction of de-icing water could be the dominatingfactor in the chloride absorption process.

    Key words: Repairs, bridge decks, bonded concreteoverlays, service life, chloride ingress.

  • 44.
    Racutanu, George
    KTH, Superseded Departments, Structural Engineering.
    Konstbyggnaders reella livslängd1998Licentiate thesis, monograph (Other scientific)
  • 45.
    Racutanu, George
    KTH, Superseded Departments, Structural Engineering.
    The real service life of Swedish road bridges2001Doctoral thesis, monograph (Other scientific)
  • 46.
    Silfwerbrand, Johan
    KTH, Superseded Departments, Structural Engineering.
    Dimensionering av plastgjutna industriytor i betong2001Report (Other academic)
  • 47.
    Thöyrä, Tom
    KTH, Superseded Departments, Structural Engineering.
    Strength of slotted steel studs2001Licentiate thesis, monograph (Other scientific)
  • 48.
    Tibert, Gunnar
    KTH, Superseded Departments, Structural Engineering.
    Numerical analyses of cable roof structures1999Licentiate thesis, monograph (Other scientific)
  • 49.
    Tibert, Gunnar
    et al.
    KTH, Superseded Departments, Structural Engineering.
    Pellegrino, S.
    Deployable tensegrity reflectors for small satellites2002In: Journal of Spacecraft and Rockets, ISSN 0022-4650, E-ISSN 1533-6794, Vol. 39, no 5, p. 701-709Article in journal (Refereed)
    Abstract [en]

    Future small satellite missions require low-cost, precision reflector structures with large aperture that can be packaged in a small envelope. Existing furlable reflectors form a compact package which, although narrow, is too tall for many applications. An alternative approach is proposed, consisting of a deployable tensegrity prism forming a ring structure that deploys two identical cable nets (front and rear nets) interconnected by tension ties; the reflecting mesh is attached to the front net. The geometric configuration of the structure has been optimized to reduce the compression in the struts of the tensegrity prism. A small-scale physical model has been constructed to demonstrate the proposed concept. A preliminary design of a 3-m-diam, 10-GHz reflector with a focal-length-to-diameter ratio of 0.4 that can be packaged within an envelope of 0.1 x 0.2 x 0.8 m(3) is presented.

  • 50.
    Tranvik, Pär
    KTH, Superseded Departments, Structural Engineering.
    Dynamic behaviour under wind loading of a 90 m steel chimney2001Licentiate thesis, monograph (Other scientific)
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