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  • 1.
    Andersson, Patrik
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Ombyggnad och tilläggsisolering av flacka tak1987Report (Other academic)
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  • 2.
    Andersson, Patrik
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Hanson, Nils
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Jakobsson, Nils M
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Vad kan idag göras åt ett typiskt småhus byggt år 1938?1982Student thesis
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  • 3.
    Ay, Lutfi
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Steel fibrous cement based composites: material and mechanical properties: behavior in the anchorage zones of prestressed bridges2004Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This PhD thesis is divided into two parts. Part one dealswith the development of the material and the mechanicalproperties of Steel Fibrous Cement Based Composites (SFCBC) forimproving bridge design and construction. It familiarizes thehydration mechanisms of the high performance concrete with thehelp of Powers´ and Jensen´s models. Concretes withdifferent water-cement ratio were compared with each other withrespect to degree of hydration and hydration products. Thisanalysis showed that high performance concrete has higherstrengths not because it has more gel solid, but due to ithaving less porosity and higher filler content compared toordinary concrete.

    A number of experiments were performed to achieve a mixdesign method for a SFCBC, which has good workability, highearly and long-term strength and good durabilitycharacteristics. A Self-compacting and self-leveling fibrouscomposite, which has ultra high strengths (Compressive strengthfc= 180 ~ 220MPa and flexural tensile strengthfföi= 14 ~ 32MPa depending on the volumefraction of fibers) was produced. This composite was alsotested under different curing conditions in order toinvestigate the effect of curing on hydration andself-desiccation shrinkage. These tests showed that SFCBCshould not be water-cured under a long period andself-desiccation influences the compressive strengthnegatively. Test of scaling at freezing showed that SFCBC hasvery good durability characteristics.

    Part two deals with the behavior of SFCBC in the anchoragezones of prestressed bridges. The prismatic composite specimenswere tested for different volume fractions of fibers underdifferent concentrations ratios of strip loading. The resultsof these tests showed that the ultimate strength of the SFCBCspecimens was approximately twice that of ordinary concretewith the same size (fc= 60MPa reinforced with stirrups). Therefore,SFCBC has good possibility to replace the traditional rebars inthe anchorage zones of prestressed bridges.

    This composite has different behavior than the traditionalconcrete e.g. crack formation, failure criteria, effectivestrength and angle of friction. A vertical crack on thecenterline was occurred while wedge developed under the loadingplate. In contrast to ordinary concrete, the cracks could notreach to the bottom of the blocks.

    The tests results gave the ideas of that this material actslike metals or plastics in the high fiber content. Thismaterial is neither very brittle as concrete nor very ductileas metals but it is somewhere between them.

    Upper-bound plasticity solutions were utilized for modelingthe bearing capacity of SFCBC. Predictions of this method aregood enough to estimate the bearing capacity of SFCBC in theanchorage zones of prestressed bridges.

    Keywords:Process improvement of bridges, Prestressedconcrete, High performance concrete, Ultra high performanceconcrete, Hydration, Cement based composites, Fibers,Self-compacting concrete, Bearing capacity, Anchorage zones,Tests

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  • 4.
    Backman, Haide
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Kudryk, Marie
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Fukt i prefabricerade träelement: En undersökning av fuktförloppet under byggskedet1981Report (Other academic)
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  • 5.
    Badanoiu, Alina
    et al.
    SIMO Department, University Politehnica Bucharest, Romania.
    Holmgren, Jonas
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Cementitious composites reinforced with continuous carbon fibres for strengthening of concrete structures2003In: Cement & Concrete Composites, ISSN 0958-9465, E-ISSN 1873-393X, Vol. 25, no 3, p. 387-394Article in journal (Refereed)
    Abstract [en]

    Continuous fibre wrapping technique is becoming a common repair and strengthening technique for concrete structures. In this method continuous fibre sheets are bonded to the surface of a concrete structure using organic resins. The main disadvantages of this method are: (i) the use of resins (organic compounds) which are hazardous for the manual worker, and (ii) the low permeability of this type of organic materials. These problems could be solved if a cement-based matrix is used instead of epoxy matrix. In the current development stage one of the limiting parameter in a cementitious carbon fibre composite is the bond between the fibres and the cementitious matrix. The main objective of the study presented in this paper was to improve the bond between the carbon fibres and the cementitious matrix. Two possible methods were studied: (i) the design of a complex binder based on Portland cement with polymer and silica fume additions and (ii) surface treatment of the carbon fibres prior to their casting in the cementitious composite.

  • 6.
    Bagampadde, Umaru
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    On investigation of stripping propensity of bituminous mixtures2004Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    In this study, an experimental programme was designed toestablish a relationship between bituminous mixture constituentmaterial properties and their propensity to moisture induceddamage in form of stripping. Six bitumen types (3 from Ugandaand 3 from Sweden) with presumably varying characteristics wereevaluated basing on rheology and chemistry. Eleven aggregateswere used in this study. Seven were sourced from activequarries in Uganda and four were from Sweden.

    Bitumen rheology was established basing on penetration,softening point, viscosity, ductility and visco-elasticparameters obtained from dynamic mechanical analysis. Bitumenchemistry was studied using Fourier Transform InfraredSpectroscopy, Gel Permeation Chromatography (GPC) and ThinLayer Chromatography (TLC).

    Bituminous mixtures were reconstituted from the bitumen andaggregate combinations basing on the Swedish mix designprocedure ROAD 94 using dense graded mixtures with 16mm maximumaggregate size (AG16). Mixture sensitivity to moisture wasevaluated basing on Swedish FAS 446-98 specifications closelyrelated to the modified Lottman procedure.

    The investigation was done in two phases namely, (a) theeffect of aggregate properties on mixture moisture sensitivityand (b) the of cross effects of bitumen and aggregates onmixture moisture sensitivity.

    The results reveal chemical compositional differences inbitumens that would be considered similar basing on classicalrheological properties like penetration and viscosity. Resultsof dynamic mechanical analysis show that binders have similarvisco-elastic response around 0oC. This could be a potentialphenomenon to serve as a grading scheme for bitumen as is thecase with penetration and viscosity grading systems.

    The results from phase I of the study show that presence ofCa-feldspars and ferromagnesian minerals in aggregates largelyrelates to improved resistance of mixtures to moisture damage.In addition, mixtures from aggregates with high concentrationsof acid insolubles (SiO2 and Al2O3) are sensitive to moisturedamage.

    The results of phase II of this study show that the choiceof aggregate type is the dominant factor affecting moisturesensitivity of the resulting mixtures. Bitumen type seems notto be an important factor in determining moisture sensitivityof bituminous mixtures. Aggregates with Ca-feldspars andferromagnesian minerals seemed to be the most resistant tomoisture damage irrespective of the bitumen type.

    Assessment of moisture sensitivity basing on absolutestiffness values of water treated mixtures seems not to bereliable. Results from this study show that mixtures withsimilar wet resilient moduli had varying tensile strengthratios, hence varying moisture sensitivity tendencies. Modulusof resilience ratio (MRR) and tensile strength ratio (TSR)parameters show similar trends in comparing moisturesensitivity of different mixtures. However, MRR values aregenerally lower than TSR values for the same mixtures.

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  • 7.
    Bagampadde, Umaru
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Isacsson, Ulf
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Kiggundu, Bob
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Classical and contemporary aspects of stripping in bituminous mixtures2004In: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, Vol. 5, no 1, p. 7-45Article in journal (Refereed)
    Abstract [en]

    Stripping or removal of bitumen from an aggregate because of water penetrating into the interface causes many pavements to fail. Stripping has been existent since the advent of paving technology. It causes functional weakening of pavements leading to costly repairs. This state-of-the-art paper deals with important concepts of stripping as, bitumen chemistry and rheology, aggregate properties (chemical and mineralogical composition, surface texture, morphology, porosity, etc), traffic, water properties, construction practices (mixing, placement and in-service drainage) and nature of antistripping additives. Adhesion of bitumen onto aggregate is explained based on theories like mechanistic tenacity, molecular orientation, chemical reaction, and thermodynamic balance of interfacial forces. Stripping is elucidated using several mechanisms namely, displacement, detachment, spontaneous emulsification, bitumen film rupture, water pore pressure, hydraulic scouring, chemical disbanding, microbial activity, osmosis; and blistering and pitting. Attendant theories to the mechanisms are explained. Moisture sensitivity test methods emerged are described and discussed. The large number of tests that have evolved shows the importance of the phenomenon of stripping. Remedial measures which include use of antistripping additives, careful selection of hot mix component materials, good construction practice, and others have been proposed for use in practice.

  • 8.
    Bahrekazemi, Mehdi
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Train-Induced Ground Vibration and Its Prediction2004Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This thesis based on a series of ground vibrationmeasurements at different sites presents two differentsemi-empirical models for prediction of ground-borne vibrationdue to train traffic.

    Ground-borne vibration due to train traffic may causeannoyance to people who live nearby the track or interfere withthe operation of sensitive equipment inside the buildings.Therefore despite the fact that ground-borne vibration fromtrain traffic usually do not cause damage to the buildings, theeconomical and environmental aspects of the issue justifycareful assessment of the problem prior to constructing newrailway tracks or upgrading the existing ones for heavier andfaster traffic. It is in this context that a model forprediction of traininduced ground-borne vibration can beuseful.

    Any model for prediction of ground-borne vibration due totrain traffic must include at least three main components.These three main components, which themselves may include manydifferent parts are the source, propagation path, and thereceiver. Depending on how detailed these three components aredefined, and how accurate the predictions made by the modelare, they can be classified into three different classes, classI, class II, and class III.

    The first model presented in the thesis is a class Iprediction model that can be integrated into a GIS system inorder to study large areas and thereby choose the best positionof a new railway or determine locations with risk for excessiveground-borne vibration in case of upgrading existing railwaysfor higher axle load and train speed.

    A class II semi-empirical model is also suggested in thethesis which can be used in order to study the problem in amore accurate way and rather short time at those locations thathave been identified by the first model. This model is based ona library of sub-models corresponding to the source, path andthe receiver. The sub-models can be put together by the user inorder to make a specially made confectionary model suitable foreach specific site and case.

    Using the measurement data some general conclusions havealso been discussed with respect to the effect of wheel force,train speed, train type, train length, geotechnical conditionsof the site, building’s dynamic characteristics, and somemitigation methods on the ground-borne vibration induced bytrain traffic.

    Key words:ground vibration, train traffic, predictionmodel, vibration effects, vibration mitigation.

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  • 9.
    Battini, Jean-Marc
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Pacoste, Costin
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Co-rotational beam elements with warping effects in instability problems2002In: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 191, no 17-18, p. 1755-1789Article in journal (Refereed)
    Abstract [en]

    The present paper investigates the formulation of 3D co-rotational beam elements for the buckling and post-buckling analysis of frame structures. Following Pacoste and Eriksson [Comput. Methods Appl. Mech. Engrg. 144 (1997) 163], the term co-rotational relates here to the provision of a local reference frame that continuously rotates and translates with the element. Within this context, several issues are emphasised. The first one refers to the parameterisation of finite 3D rotations. The alternative put forth in the paper is based on the spatial form of the incremental rotational vector. The second issue concerns warping effects which are introduced by adding a seventh degree of freedom at each node. Different types of local formulations are considered and it is shown that at least some degree of non-linearity must be introduced in the local strain definition in order to obtain correct results for certain classes of problems. Within the present approach the centroid and shear center of the cross-section are not necessarily coincident. Finally, in the context of instability problems, a method for the direct computation of critical points is also briefly discussed, This is based on a minimal augmentation procedure as developed by Eriksson [Comput. Methods Appl. Mech. Engrg. 156 (1998) 45; Comput. Methods Appl. Mech. Engrg. 179 (1999) 265; Int. J. Struct. Stability Dynamic 1 (1) (2001)]. Ten examples, including large displacement and stability problems, are used in order to assess the performances of the elements.

  • 10.
    Battini, Jean-Marc
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Pacoste, Costin
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Plastic instability of beam structures using co-rotational elements2002In: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 191, no 51-52, p. 5811-5831Article in journal (Refereed)
    Abstract [en]

    In a previous paper [Comput. Methods Appl. Mech. Engrg. 191 (2002) 1755], the authors have presented a 3D co-rotational elastic beam element including warping effects. This formulation is now further developed in order to incorporate elasto-plastic deformations. The element possesses seven degrees of freedom at each node and can be used to model beams with arbitrary cross-sections. Thus, within the present approach, the centroid and shear center of the cross-section are not necessarily coincident. The main purpose of this element is to model elasto-plastic instability problems. In this context, two methods of branch-switching are tested and discussed. In the first one, the bifurcation point is isolated by successive bisections and the branch-switching is operated by using the eigenvector associated to the negative eigenvalue. In the second one, introduced by Petryk, an energy approach is used to select automatically the stable post-bifurcation path. Six examples, including large displacement and stability problems, are used in order to assess the performances of the element.

  • 11.
    Bayoglu Flener, Esra
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Field Testing of a Long-span Arch Steel Culvert Railway Bridge over Skivarpsån: Part I2003Report (Refereed)
  • 12.
    Bayoglu Flener, Esra
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Soil-structure interaction for integral bridges and culverts2004Licentiate thesis, monograph (Other scientific)
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  • 13.
    Bengt, Wånggren
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Studier av byggnads-, installations- och drifttekniska åtgärder för energibesparing i äldre byggnader.: Ulvsundaprojektet Etapp II1987Report (Other academic)
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  • 14.
    Bergström, Anna
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Winter maintenance and cycleways2002Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Increasing cycling as a means of personal travel couldgenerate environmental benefits if associated with acorresponding decrease in car-based transport. In seeking topromote cycling in wintertime, it is desirable to understandhow important the road surface condition is compared to otherfactors in people's decision to cycle or not. In this thesis,the possibility of increasing the number of cyclists byimproving the winter maintenance servicelevel on cycleways isexamined. The attitudes towards cycling during winter ingeneral, and in relation to winter maintenance of cycleways inparticular, is studied through questionnaire surveys. Bicyclemeasurements are related to weather data from Road WeatherInformation System, in order to know the influence on cycleflow during winter from different weather factors. Fieldstudies are performed testing unconventional winter maintenancemethods, in order to see if a higher service level could beachieved on cycleways and if that would lead to an increase inwinter cycling frequency. The field studies are evaluatedthrough road condition observations, measurements of friction,bicycle counts, a questionnaire survey and interviews. A visualmethod to assess winter road conditions on cycleways isdeveloped, in order to compare the service levels achievedusing different winter maintenance methods.

    There is a clear difference in mode choice between seasons.With improved winter maintenance service level it could bepossible to increase the number of bicycle trips to work duringwinter with, at the most, 18 %, and decrease the number of cartrips with 6 %. However, it could not be concluded with bicyclemeasurements, that an enhanced service level in fact, generateda higher winter cycling frequency.

    To increase cycling during winter, snow clearance is themost important maintenance measure. Skid control is not assignificant for the choice of mode but is important to attendto for safety reasons. Winter road condition propertiesimportant both with regard to safety and accessibility ofcyclists, are icy tracks formed when wet snow freezes, snowdepths greater than about 3 cm of loose snow or slush,unevenness in a snow covered surface, loose grit on a baresurface.

    Weather factors with negative influence on winter cyclingfrequency, are temperatures below +5 ° C,precipitationand strong winds. Only the occurrence of precipitation, not theamount of rain or snow, is significant for the cycle flow. Lowtemperatures are more important in reducing the cycle flow thanprecipitation. Temperatures around 0 ° C seem to be extracritical for cyclists, probably due to the larger influence ofprecipitation and slippery road conditions at thesetemperatures.

    An unconventional method using a power broom for snowclearance and brine or pre-wetted salt for de-icing, provides ahigher service level than winter maintenance methodstraditionally used, but it is about 2 to 3 times moreexpensive. The method has great potential in regions, such assouthern Sweden, with low snow accumulations but with major iceformation problems. To assess the maintenance service level,the visual assessment method developed and tested in thisproject is adequate for the purpose, however, furtherimprovements are desirable. As a complement to the visualassessment, a Portable Friction Tester can be used to measurethe surface friction on cycleways during wintertime.

    Keywords:Cycleways, winter maintenance, maintenanceservice level, mode choice, winter cycling frequency, wintermaintenance equipment, winter road condition assessment,bicycle measurements, friction measurement.

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  • 15.
    Björk, Folke
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Fast installation av utrustning för läcksökning på terassbjälklag: En möjligthet att undvika problem i byggprocessen och förvaltningsprocessen2004Report (Other academic)
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  • 16.
    Björk, Folke.
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Eriksson, C. A.
    Measurement of alkalinity in concrete by a simple procedure, to investigate transport of alkaline material from the concrete slab to a self-levelling screed2002In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 16, no 8, p. 535-542Article in journal (Refereed)
    Abstract [en]

    A test procedure for measurement of alkalinity for cementitious materials that is, reliable, simple. and only needs a small amount of sample, was developed and applied to check whether transport of alkaline material from a concrete surface to a covering screed can result in a detectable increase in pH-value. It was found that any transport of alkaline material from a rather humid concrete did not increase the level of alkalinity (or pH-value) of the screed covered with a carpet. It was noted that carbonation Occurred gradually from the surface and inwards when the materials were exposed to ambient air. For the prisms, of 95%, RH pH-value in the concrete surface increased with time. A transport process that allows hydroxide ions solved in the pore water in the concrete to diffuse towards the carbonated surface and thus give an increased pH-value, can explain this.

  • 17.
    Björk, Folke.
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Eriksson, C. A.
    Karlsson, Sigbritt
    KTH, Superseded Departments (pre-2005), Polymer Technology.
    Khabbaz, F.
    Degradation of components in flooring systems in humid and alkaline environments2003In: Construction and Building Materials, ISSN 0950-0618, E-ISSN 1879-0526, Vol. 17, no 3, p. 213-221Article in journal (Refereed)
    Abstract [en]

    Constituents from products that are used in the flooring on a concrete slab such as carpets of plasticised PVC and water-based adhesives sometimes degrade in an alkaline and humid environment. The concrete itself could be such an environment. In order to examine the effect of different levels of alkalinity and humidity on the mentioned products a specialised procedure was developed. By this procedure it was possible to imitate the effect of an environment of alkalinity and humidity corresponding to a recently produced concrete slab on different substances and also collect volatile degradation products produced. Degradation of some of the constituents was dependent on the levels of alkalinity and humidity, although there were significant differences in the possibility to resist the environmental factors. For some of the components, an increase in alkalinity resulted in a much higher production of degradation products even when the relative humidity was kept on a comparatively low level. The results give basis for a recommendation not to adhere plastic floorings directly to a recently produced slab of high-quality concrete because the alkaline material in the concrete could cause degradation.

  • 18.
    Björk, Folke.
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Granne, F.
    Roof membranes - The Swedish practice in light of EOTA TB 97/24/9.3.1 PT3 durability2000In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 33, no 228, p. 270-277Article in journal (Refereed)
    Abstract [en]

    The practice for roof membranes for flat and low-slope roofs has substantially developed during the last two decades of the twentieth century. New technical solutions have been introduced and building codes and guidelines have been changed. The development of technical solutions preceded the scientific work. However, the scientific work did help to develop the technical practice for enhanced performance. The development described in this paper has much in common with recently published EOTA-guidelines regarding Assessment of service life.

  • 19.
    Björk, Folke
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Mattson, Bertil
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Uppföljning av erfarenheter från Småhusskadenämndens arbete2002Report (Other academic)
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  • 20.
    Björk, Folke
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Oba, Koichi
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Fogningsteknik för Mekaniskt Infästa Taktäckningar av Polymermodifierad Bitumen1995Report (Other academic)
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  • 21. Blas, M.
    et al.
    Sobik, M.
    Quiel, Friedrich
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Netzel, P.
    Temporal and spatial variations of fog in the Western Sudety Mts., Poland2002In: Atmospheric research, ISSN 0169-8095, E-ISSN 1873-2895, Vol. 64, no 04-jan, p. 19-28Article in journal (Refereed)
    Abstract [en]

    The ridges of the Western Sudety are well exposed to the humid maritime air masses that are mainly associated with westerly atmospheric circulation. Fog is the most frequently observed atmospheric phenomenon, being present on average 45% of the time, with 250-300 days with fog per year. This study on temporal variation of fog in both daily and annual cycles is based on 30 years of measurements (1961 - 1990) made on Mt. Szrcnica at 1362 m a.s.l. Based on the data from 51 meteorological stations and the results of fog deposition field measurements, a digital model of fog frequency in the Western Sudety was prepared using a Geographic Information System. The model shows that altitude is not the only important factor controlling fog frequency. Such parameters as slope aspect and position of a particular site in relation to local and regional morphology are also of crucial importance.

  • 22.
    Blomqvist, Claes
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Okoventionell tillförsel av ventilation2000Licentiate thesis, comprehensive summary (Other scientific)
  • 23.
    Blomqvist, Claes
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Sandberg, Mats
    Högskolan i Gävle, Avdelningen för inomhusmiljö.
    A Note on Air Movements through Horizontal Openings in Buildings2002In: The 8th International Conference on Air Distribution in Rooms: Inividual Controlled Environment, 2002Conference paper (Refereed)
  • 24.
    Blomqvist, Claes
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Sandberg, Mats
    Högskolan i Gävle.
    Air Movements through Horizontal Openings in Buildings – A Model Study2004In: The International Journal of Ventilation, ISSN 1473-3315, E-ISSN 2044-4044, Vol. 3, no 1, p. 1-10Article in journal (Refereed)
    Abstract [en]

    A building contains a number of large openings like doors and staircases. When the temperature of the spaces connected by these openings differs, the difference in density will cause air movements through them. Horizontal air movements through vertical openings in buildings like doors and windows are well investigated while studies of air movements through horizontal openings like stairwells are less frequent and therefore this work is focusing on this case.

    The paper reports on an experimental study of the possibility of using buoyancy forces to distribute air and heat through horizontal openings. The experiments have been carried out in a scale model with water as the operating fluid.

    The result of the study shows that the flow rate through a horizontal opening is roughly half of the flow rate through a vertical opening for the same conditions, probably caused by the more complex flow pattern in the horizontal opening. A staircase below the horizontal opening will guide the flow somewhat and will cause a small increase of the fluid exchange through the opening.

  • 25.
    Blomqvist, Claes
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Sandberg, Mats
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Measurements and Control of Air Movements within a Building1997In: 18th AIVC Conference: Ventilation and Cooling, 1997, p. 427-436Conference paper (Other academic)
    Abstract [en]

    There are a number of methods available concerning with distribution of air in buildings. Within control research, one can find new control algorithms which have not yet been used in practice. These new algorithms open the possibility of developing and implementing of new demand controlled ventilation systems.

    In a building the internal air motions are due both to differences in temperature and pressure differences caused by the ventilation system. Therefore, one fundamental question is to what extent it s possible to control the air motions within a building using fan powered ventilation in combination with temperature control.

    The aims of this paper is to report on measurements done to examine the influence of temperature differences between rooms on the air exchange through open doors in a building and to explore the use of modern control technique to minimise the temperature difference.

    The result of the measurements shows that even very small (0.1-0.2°C) temperature differences between rooms cause bi-directional air flows in the doorways of a magnitude that exceed the flow rates caused by the mechanical ventilation system. Therefore it is necessary to control the temperatures in the rooms to make it possible for the ventilation system to distribute the air to those parts of the building where it is needed.

  • 26.
    Blomqvist, Claes
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Sandberg, Mats
    Högskolan i Gävle, Avdelningen för inomhusmiljö.
    Spread of Gravity Currents within a Multi-Room Building2000In: The 7th International Conference on Air Distribution in Rooms: Ventilation for Health and Sustainable Environment, 2000Conference paper (Refereed)
  • 27.
    Blomqvist, Claes
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Sandberg, Mats
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    To what extent can one with mechanical ventilation control the air motions within a building1996In: ROOMVENT'96: 5th International Conference on Air Distribution in Rooms, 1996, p. 265-272Conference paper (Other academic)
    Abstract [en]

    There are a number of methods available concerning with air distribution in buildings. Within control research, one can find new control algorithms which have not been used in practice yet. These new algorithms open the possibility of developing and implementing of new demand controlled ventilation systems.

    In a building the internal air motions are due both to differences in temperature and due to pressure differences induced by the ventilation system. Therefore, one fundamental question is to what extent one can with fan powered ventilation control the air motions within a building.

    The aims of this paper is to report on development of methods to study the air motions in a multi room residence apartment using various combinations of exhaust and supply air management. The experimental work includes measurements of air flow rates in door openings in both directions and use of various tracer gas methods to determine the supply air flow to each room, and identifying flow paths.

    In an accompanying paper (Björsell 1996) is reported on the results from a simulation of the performance of different control algorithms.

  • 28.
    Blomqvist, Claes
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Sandberg, Mats
    Högskolan i Gävle, Avdelningen för inomhusmiljö.
    Transition from Bi-directional to Unidirectional Flow in a Doorway1998In: ROOMVENT '98 : proceedings: 6th International Conference on Air Distribution in Rooms, 1998, p. 539-546Conference paper (Refereed)
    Abstract [en]

    The air flow in a doorway is governed by density difference caused by temperature difference and pressure difference caused by mechanical ventilation. Tests have been carried out in a unique indoor test house where the room to room to temperature difference could be controlled very accurately with a new control system. In addition to these tests some tests were carried out in a scale model with water as the operating fluid. Two main criteria of unidirectional flow in a doorway have been explored:

     

    1a.     The recorded mean velocity is unidirectional

    1b.     The neutral height is equal to the height of the door

    2.       Unidirectional flow in the sense that

     

    there is no transfer of contaminant from one room to another. To explore condition one the velocity profile in the doorway have been recorded by transversing the door opening. Condition two has been explored by using tracer gas technique.

  • 29.
    Boman, Eva
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Noise in the school environment - Memory and Annoyance2004Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Objectives.The general objectives of this dissertationwere to examine the effects of acute exposure to meaningfulirrelevant speech and road traffic noise on memory performance,and to explore annoyance responses to noise exposure in theschool environment for pupils and teachers in different agegroups.

    Methods. The thesis comprises seven papers, representingdifferent methodological approaches: experiments, surveystudies and interviews. In the experiments, reported in PapersI-V, 288 pupils and teachers participated in the age groups,13-14 years (n=96), 18-20 years (n=96), 35-45 years (n=48) and55-65 years (n=48). The subjects were randomly assigned to oneof three conditions: (a) meaningful irrelevant speech, (b) roadtraffic noise, and (c) silence. The equivalent sound level inthe noise conditions was set to 66 dB(A). A test batteryreflecting episodic and semantic memory were used. The surveystudies, reported in Paper VI and VII, included 207 pupils(M=13.5) and 166 teachers (M=45.9). Two separate questionnairesmainly comprising items about annoyance, noise sensitivity andstress symptoms were administered. Paper VI presents results offocus group interviews (n=16) treating the main topics:disturbing sounds, emotions, ongoing activity, and suggestionsconcerning future changes. Results. The overall findings showedthat both noise sources affected episodic and semantic memoryto the same degree for all age groups. The results indicatedthat the similarity of semantic content between noise and thetask at hand was not the only suitable explanation model, sincea non-speech noise impaired memory as much as speech.

    Resultsalso indicated that attention effects did notmediate the obtained noise effects and that the noise effectsdid not differ between age groups. Therefore, it seemedunlikely that different memory and attentional capacities stoodout as explanatory factors of the memory effects. Sinceperformances of both episodic and semantic memory tasks wereimpaired, the explanation based on level of access to long-termmemory was also ruled out. However, the episodic memory task,reading comprehension, stood out to be most impaired by noise,suggesting that complexity of the task to perform was ofimportance. For reading comprehension there was also adifferent noise pattern obtained. Participants performance wasin this task, more impaired by meaningful irrelevant speechthan by road traffic noise. This effect indicated thatmeaningful irrelevant speech might reduce the availablecognitive resources necessary for learning the text. Theannoyance models derived from the survey studies indicated thatsensitivity acted as a mediator between hearing status andannoyance, with stress symptoms as an outcome. Whetherannoyance arises or not was also determined by control andpredictability of the noise. In the interviews a differentannoyance pattern was found, in that stress symptoms appearedto be a determinant of annoyance. To be involved, respected,take own responsibility and respect others were suggestions onhow to change the environment to become more silent.

    Conclusions.For both pupils and teachers acute exposureto meaningful irrelevant speech and road traffic noiseinfluenced both the achieving and providing of knowledge. Acommon annoyance pattern was also found for pupils andteachers, where individual and situational factors were ofimportance. To achieve a more silent school environment in thefuture, the pupils pointed out that the interaction betweenthemselves and their teachers was of importance.

    Key words:Noise, meaningful irrelevant speech, roadtraffic noise, memory, age groups, school environment, pupils,teachers

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  • 30.
    Boman, Eva
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Enmarker, Ingela
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Factors affecting pupils' noise annoyance in schools: The building and testing of models2004In: Environment and Behavior, ISSN 0013-9165, E-ISSN 1552-390X, Vol. 36, no 2, p. 207-228Article in journal (Refereed)
    Abstract [en]

    This article reports two studies intended to develop and assess conceptual models of how different factors mediate and moderate the annoyance reaction in school environments. In the first, a survey of 207 pupils was conducted where assumptions about mediators and moderators were formulated and tested. In the best model, general sensitivity and adaptation led to a higher degree of annoyance causing stress symptoms. In the second study, focus group interviews with 16 pupils were performed to set up a model of mediating and moderating factors from pupils' statements in the formation of annoyance. The objective was also to get their opinions about ways to improve the sound environment in school. The interviews indicated a serial arrangement in which stress symptoms and distraction mediated between chatter and disturbance. Thus, the two studies suggested different models for the prediction of the annoyance reaction. The pupils' views about how to improve the school sound environment are discussed in the framework of an empowerment model.

  • 31.
    Brandt, Ove
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Bring, Christer
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Stegljudsisolering och beständighet mot intryck hos golvbeläggningar på massivbjälklag av betong1961Report (Other academic)
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  • 32. Brantberger, M.
    et al.
    Stille, Håkan
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Eriksson, M.
    Controlling grout spreading in tunnel grouting - Analyses and developments of the GIN-method2000In: Tunnelling and Underground Space Technology, ISSN 0886-7798, E-ISSN 1878-4364, Vol. 15, no 4, p. 343-352Article in journal (Refereed)
    Abstract [en]

    In order to choose the best grouting technique, predictions of the grouting result can be made. Due to uncertainties in the predictions, control of the grouting during ongoing work is an important step towards a successful result. One method to control the grouting is the GIN-method developed and presented by Lombardi and Deere (1993). The method focuses on controlling the grout spreading in order to minimise the risk of hydraulic uplift and achieve a more uniform spreading around a bore hole. However, this method is described with emphasis on dam grouting. In this paper, theories are analysed and developed from a tunnel grouting point of view. A concept of a normalised pressure and normalised grout spreading is presented that at the same time enables control of the grout spreading distance as well as the risk of hydraulic uplift. Calculations based on field data are also done in order to visualise and discuss the potential use of developed theories. Some conclusions from the performed analyses are that other mathematical relations than those stipulated by the GIN-method better account for the risk of hydraulic uplift and that higher pressures than the rule of thumb stipulates could be used in good rock. So far, the concept of normalised pressure and normalised grout spreading is in its first stage and is studied mainly from a theoretical point of view. Further studies are thus needed.

  • 33.
    Bring, Christer
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Provningsmetoder för golvmaterial och golvkonstruktioner1968Report (Other academic)
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  • 34.
    Bring, Christer
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Vidhäftning mellan hårdnat betongunderlag och pågjutet golvskikt1967Report (Other academic)
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  • 35.
    Brosenius, Hilding
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Direkt elvärme eller flexibel vattenburen värme?1970Report (Other academic)
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  • 36.
    Brosenius, Hilding
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Om uppvärmningssystem vid småhus1970Report (Other academic)
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  • 37.
    Brosenius, Hilding
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Nuder, Ants
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Fönsterareor vid kontorshus1966Report (Other academic)
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  • 38.
    Buø, F
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Elmroth, A
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Friström, G
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Sällström, S
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Some investigations concerning winter concreting: Required insulation and pre-hardening time for concrete with low-heat cement1967Report (Other academic)
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    fulltext
  • 39.
    Buø, F.
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Elmroth, Arne
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Friström, G.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Sällström, S.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Vintergjutning och formisolering vid vattenkraftanläggningar1968Report (Other academic)
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  • 40.
    Carlsson, Benny
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Zagierski, Jaroslaw
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Jämförande studier av infästningssätt av takfönster1985Report (Other academic)
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  • 41.
    Carlsson, Kjell
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Stomkonstruktioner i moderna kontorshus1965Report (Other academic)
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  • 42. Clarke, J A
    et al.
    Conner, S
    Fujii, Gen
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Geros, V
    Jóhannesson, Gudni
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Johnstone, C M
    Karatasou, S
    Kim, J
    Santamouris, M
    Strachan, P A
    The role of simulation in support of Internet-based energy services2004In: Energy and Buildings, ISSN 0378-7788, E-ISSN 1872-6178, Vol. 36, no 8, p. 837-846Article in journal (Refereed)
    Abstract [en]

    The connection of buildings to the Internet broadband network is becoming commonplace. The establishment of such an infrastructure enables the development of a range of new energy, environment and health-related services for people in their homes and workplaces. Telecommunications companies and utilities are actively developing examples of such services, and local authorities and health care providers are supporting trial deployments. Several of the services can be enabled or enhanced through the application of building modelling and simulation. This paper describes the infrastructure for the e-services under test within a European research project and shows the potential for simulation support for these services.

  • 43.
    Cousins, Martin
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Wind Uplift Resistance of Fixed Roof Tiles: Study of Test Methods1999Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
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  • 44.
    Dahlberg, Jens-Olof
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Skägg, Jan
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Tekninsk funktion hos lågenergihus - Projekt sparsam1982Student thesis
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  • 45.
    Dahlman, Anders
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Bengtsson, Björn
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Ljudisoleringsegenskaper hos fönsterkonstruktioner1980Student thesis
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  • 46.
    Dalmalm, Thomas
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Choice of grouting method for jointed hard rock based on sealing time predictions2004Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    This thesis concerns subjects related to the choice of agrouting method in a jointed hard rock mass. By calculating thetotal sealing time to reach the requested sealing level,different grouting methods could be compared and the mostfavourable chosen.

    A methodology, to calculate the sealing time for differentgrouting methods in different rock masses has been developed.Five main activities are included in the methodology; drilling,grouting, waiting, probing and re-grouting, which to differingdegrees contribute to the total sealing time. In addition, anextra activity, post-grouting, is regarded separately, as thepost-grouting time normally is not included in the totalsealing time. Within the different activities, subjects such asrock mass properties, examination of rock mass, groutingtechnique, grout mix and the different waiting times have beenstudied.

    In practice, the application of the methodology requiresthat the average time and variance for each activity on a fanlevel is expressed. The times for each activity are then addedtogether to achieve the total time for a fan. After which, thetime for each fan is added over the entire tunnel length tocalculate the total sealing time for a tunnel.

    E.g. for the grouting activity, joints belonging to agrouting fan are randomly selected from a joint aperturedistribution for the appropriate rock mass. For each joint in afan, distributions are calculated for parameters such asinflow, time and grouting volumes as e.g. sealing time andsealing effect. Then a Monte Carlo simulation based on thesedistributions and for each grouting fan is carried out and theaverage grouting time and variance calculated.

    To test the methodology, numerical calculations for threegrouting methods and in three rock masses have been carriedout. The most favourable grouting method is defined as themethod which fulfils the requirement in the shortest sealingtime.

    By analysing the result of the numerical calculations, ithas been shown that other activities besides grouting oftenhave a large impact on the total sealing time. To choosebetween pre-grouting and post-grouting is regarded as adecision problem, which is strongly related to other activitiesof the tunnel production cycle. A strong relationship was shownbetween the possibility to seal and the chosen grouting methodand grout mix. A long grouting time is not always equivalent toa good sealing result and the opposite has shown to bepossible.

    Further, calculations have shown that a correct combinationof hole spacing, grout penetration length and appropriatepumping time is essential for a good sealing result. Inaddition, this thesis has demonstrated a method as to how thiscorrect combination should be chosen in order to achieve anoptimal grouting solution. However, a decision regarding anappropriate grouting method, always needs to regard otheractivities of the tunnel production cycle.

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  • 47. Di Benedetto, H
    et al.
    de la Roche, C
    Baaj, H.
    Pronk, A.
    Lundström, Robert
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Fatigue of bituminous mixtures2004In: Materials and Structures, ISSN 1359-5997, E-ISSN 1871-6873, Vol. 37, no 267, p. 202-216Article in journal (Refereed)
    Abstract [en]

    This paper presents an interlaboratory test campaign organized by the RILEM 182-PEB Technical Committee. In the campaign, 11 different test methods, comprising uniaxial tension/compression, 2-, 3- and 4-point bending and indirect-tension tests, were utilized in order to investigate fatigue characteristics of a dense graded asphalt concrete mixture. The testing conditions specified were sinusoidal excitation at 10Hz and 10degreesC using controlled strain and stress modes. In total, more than 150 fatigue tests were carried out during the investigation. The fatigue test results were analyzed using both classical as well as continuum damage mechanics approaches. The fatigue test results obtained using the classical fatigue approach are considerably influenced by test type and mode of loading (controlled stress or strain) used. Consequently, this approach has limited use in realistic fatigue characterization of bituminous materials and pavement structures. In contrast to the classical approach, models founded on continuum damage theory may serve to isolate intrinsic fatigue characteristics from the influence of so-called biased effects, which are largely caused by the accelerated laboratory testing. The continuum damage models investigated may constitute steps, towards a rational mechanistic fatigue characterization model, which are important for effective future pavement design.

  • 48.
    Edwards, Ylva
    et al.
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Redelius, Per
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Rheological effects of waxes in bitumen2003In: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 17, no 3, p. 511-520Article in journal (Refereed)
    Abstract [en]

    Rheological effects of adding two bitumen waxes (isolated from SEC-II fraction) to three bitumens were studied using dynamic mechanical analysis (DMA). Also, a commercially available slack wax was used in the study. The results show that the magnitude and type of effect on bitumen rheology depend on the bitumen and type of crystallizing fraction in the bitumen. Effects due to wax content shown in DMA temperature sweeps are well related to the corresponding effects shown in DSC thermograms. The slope of the logarithm of the complex modulus between 25 degreesC and 60 degreesC is introduced as a possible proper factor for predicting rutting sensitivity due to wax content.

  • 49.
    Ekblad, Jonas
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Influence of water on resilient properties of coarse granular materials2004Licentiate thesis, monograph (Other scientific)
  • 50.
    Ekstedt, Jan
    KTH, Superseded Departments (pre-2005), Civil and Architectural Engineering.
    Studies on the barrier properties of exterior wood coatings2002Doctoral thesis, comprehensive summary (Other scientific)
    Abstract [en]

    Coatings for exterior wood have two basic functions. One isto give an aesthetically acceptable surface appearance andcolour. The other is to provide protection against wooddegradation by microbiological or physical attack. Theseprotective properties, often called the barrier properties,play an important role in the selection of proper material forsupreme durability. The assessment of these barrier propertiesis of great importance. Within the CEN Technical Committee 139,Working Group 2, Coatings for exterior wood test methods andperformance specifications have been established. Forassessment of water protection efficiency a standard testprocedure, EN 927-5, has been launched. The present work hasfocused on its applicability in assessing water protectionefficiency in relation to the degradation of coatings duringexposure.

    Assessments according to EN 927-5 is shown to givesignificant differences in water absorption values fordifferent types of coatings on wood. The proposed performancespecifications in ENV 927 - 2 for the water absorption valuesfor coatings to be used in different constructions seem to beset at acceptable levels. It has been shown that there is agood correlation between the level of water absorption andpractical experience of the performance of paints inScandinavia. However, it has also been shown that thecombination of a standard procedure for water absorptionmeasurement and an artificial weathering procedure gives moreinformation regarding expected durability and longtermperformance than a single measurement of water absorption onfresh, unweathered coated wood. A combination of waterabsorption measurement and artificial weathering could become auseful tool in product development as well as in benchmarking.Together with statistical tools, such as reliability-basedservice life prediction methodologies for predicting theservice life of coating systems a reduction in testing timesmay be achieved.

    Surface-active substances in coatings have a negative effecton the coatings ability to prevent water ingress, which mostprobably is due to the hydrophilic character of thesesubstances. The presence of these substances, which are commonin waterborne coatings, alters the moisture sorptioncharacteristics of wood. Considering that these substancesoccur in waterborne coatings, may be mobilised during and afterfilm formation and accumulate at the coating/substrateinterface, there is a great probability that these substanceschange the moisture sorption characteristics of the woodsubstrate in an unfavourable way and create unexpected dynamicmoisture conditions at the coating/wood interface.

    Computerized tomography has been found to be a valuable,non-destructive tool for visualising the spatial moisturedistribution of water and moisture in coated wood panels. Themethod is suitable for recurrent testing of a specimen exposedto a series of processes of wetting, drying. This thesis showsthat high moisture contents occur locally at and around cracks.In these areas there is an increased risk of internal tensionand stress resulting in crack initiation and propagation andthat high moisture contents may occur in the first fewmillimetres under waterborne coatings despite intact coatingfilms. Even with good barrier properties of the coating,moisture may accumulate by water-vapour absorption in air gapsbehind the cladding thus causing favourable conditions formicrobiological colonization.

    The work that has been carried out regarding assessment ofthe water protection efficiency shows promising resultsregarding the possibility to use reliability-based service lifeprediction methodology for the assessment. The aim of futurework will be to establish more reliable techniques andprotocols for assessing service life expectancy and durability,especially for waterborne coatings with special focus ontendencies to early failure and robustness of the coatingsystems.

    Keywords:Coatings, surfactants, water absorption value,EN 927, paint, additives, moisture dynamics, absorption,desorption, artificial weathering, artificial exposure,computerized tomography, MRI.

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