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  • 201.
    Vieira, Tiago
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial. VTI.
    Sandberg, Ulf
    VTI.
    Erlingsson, Sigurdur
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap. VTI.
    Negative texture, positive for the environment: effects of horizontal grinding of asphalt pavements2019Ingår i: International Journal on Road Materials and Pavement Design, ISSN 1468-0629, E-ISSN 2164-7402, s. 1-22Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A pavement surface having deflections from a plane mostly directed downwards in valleys is said to have a “negative texture”, in contrast to a “positive texture” dominated by peaks. Negative textures are typical of porous asphalt pavements, but another way to achieve this feature is to grind off the peaks of the surface. This paper explores the effects of grinding off texture peaks in the horizontal plane on a number of Swedish asphalt pavements in order to reduce noise and rolling resistance. Noise measurements were made to evaluate the ground-off surfaces versus the original surfaces, and, in most cases, also rolling resistance, texture and friction were also evaluated. It was found that grinding led to a more negative texture, tyre/road noise reductions up to 3 dB and tyre/road rolling resistance reductions up to 15%. It is concluded that horizontal grinding provides a maintenance operation with a significant potential for reduction of noise and rolling resistance, without sacrificing friction, though with limited longevity.

  • 202.
    Vrána, Tomás
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Impact of moisture on long term performance of insulating products2005Ingår i: Proceedings of the Nordic Symposium on Building Physics, Reykjavik, 2005, Vol. 1, s. 71-77Konferensbidrag (Refereegranskat)
  • 203.
    Werner Åström, Petter
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Experimental study on innovative connections for large span structural timber trusses2019Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Large span timber trusses are usually built with glulam. One problem with large span glulam trusses is that the connections needed to transfer the load between truss members are often complex and expensive. Another issue is transportation. Building large span trusses out of structural timber instead, could be a way of simplifying the connections and at the same time increase the degree of on-site construction and thereby solving the transportation problem.In this study, a total of 18 laboratory tests were performed with the purpose of investigating the tensile strength and the load slip behavior of different connection designs for large span structural timber trusses. Six different test groups corresponding to six different connection designs were tested. The materials used include members made of C24 timber and gusset plates made of birch plywood, aluminum, and steel. Screws were used as fasteners for five test groups and adhesive was used for one group. The influence of different reinforcement techniques including reinforcement screws and added aluminum sheets was studied.The results showed a ductile failure behavior for all test groups except for the group where adhesive was used. However, a decrease of ductility was observed for groups were aluminum sheets were used on the outsides of the mid placed plywood gusset plate. A 12-17 % increase in capacity was observed due to the presence of aluminum sheets. The reinforcement screws had no significant effect on the capacity. However, the presence of reinforcement screws did lead to a reduction in scatter both regarding capacity and stiffness.

  • 204. Westin, Mats
    et al.
    Larsson Brelid, Pia
    Segerholm, Kristoffer
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Van den Oever, M.
    Wood Plastic Composites from Modified Wood: Part 3. Durability of WPCs with bioderived matrix2008Ingår i: The 39th Annual Meeting of the International Research Group on Wood Preservation, 2008Konferensbidrag (Refereegranskat)
    Abstract [en]

    The decay resistance of fully bio-derived wood plastic composites, WPCs, was tested in bothlaboratory and field tests. The laboratory tests were performed according to modified versionsof AWPA E10 (soil-block test) and ENV 807 (tests in three un-sterile soils) and the field testsaccording to EN 252 (stakes in ground) and EN 275 (resistance to marine borers). The WPCmaterials for laboratory tests were injection molded test specimens with 50% modified woodparticles and 50% cellulose ester (CAP) or poly-lactic acid (PLA) content. The field testspecimens were taken from larger extruded decking board profiles with 60% wood contentand 40% CAP. 60/40-mix (wt/wt) for CAP corresponds to the same volumetric compositionas 70/30-mix (wt/wt) with polypropylene as matrix that was presented in Part 1 and 2.In all laboratory tests the control WPCs performed much better than the pine sapwood controlblocks. The WPCs from modified wood performed better than the control WPC and WPCsfrom acetylated wood performed best with no detectable decay whatsoever.In the field stake test, the WPC from unmodified wood were slightly decayed whereas theWPCs from modified wood were sound. In the marine field test the WPC from unmodifiedwood were severely attacked by shipworm (Teredo navalis), whereas the WPCs frommodified wood were sound.

  • 205.
    Wincrantz, Christian
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Finger-jointing of acetylated Scots pine using a conventional MUF resin2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Acetylation of wood is a modification technique that chemically alters the wood substance and enhances several properties of wood. The basic principle is to impregnate wood with acetic anhydride to react and replace OH-groups with acetyl groups in the wood cell wall. In this way, the hygroscopicity of the modified wood is significantly reduced resulting in increased dimensional stability and durability compared with unmodified wood.The objective of this work was to study finger-jointing of acetylated Scots pine (Pinus sylvestris L.) using a conventional melamine urea formaldehyde (MUF) adhesive. Two different types of acetylated pine specimens were investigated, acetylated pine sapwood (APS) and acetylated juvenile pine (AJP), the latter originating from young forest thinning trees (ca 20-30 years). The goal was to evaluate the bending strength, i.e. modulus of rupture (MOR), of such finger-jointed samples, in particular when the acetylated wood was combined with unmodified wood, in this case, Norway spruce (Picea Abies L. Karst) (US). The finger-jointing were performed at Moelven Töreboda by applying their existing industrial procedures. In total, five different of finger jointed sample groups were prepared combining the different specimens: APS-APS, AJP-AJP, US-US, APS-US, and AJP-US. Standardized procedures were used to determine the MOR of the finger-jointed samples, both unexposed at the factory condition state and after a water-soaking-drying cycle. In addition, the experiments also included determination of the moisture content (MC), density, and modulus of elasticity (MOE) (in bending along the grain) of the individual specimens.At the unexposed state, the APS-APS samples showed the highest MOR of 63,1 MPa, while those of the AJP-AJP showed the lowest value of 42,4 MPa. The corresponding values for the US-US, AJP-US and APS-US samples was 56,7, 47,5 and 46,9 MPa, respectively. In contrast to a typical wood failure for the US-US samples, a low amount of wood failure was observed in all cases involving the acetylated wood, indicating a low adhesive anchoring in the wood substrate at the finger-joint, although a surprisingly high strength was obtained for the APS-APS samples. A significantly lower MC content of 4,9 % and a remarkably low value of 1,7 %, was found for the APS and AJP, respectively, compared with 9,2% for the US. The significantly lower MC combined with an assumed increased hydrophobicity of the acetylated wood possible causes a less effective MUF-wood bonding, or adhesion, compared with that of the unmodified wood. Possible, so-called over penetration of the MUF resin in the acetylated wood could also be an explanation for the poor wood-adhesive anchoring. The MOE of the individual APS, AJP and US specimens was 12,6, 8,3 and 11,4 GPa, respectively, indicating a significantly lower mechanical performance of AJP, and hence also of finger-joints of AJP, despite its very low MC, possible due to a higher microfibril angle in the cell walls in juvenile wood compared with mature wood. No clear correlation was found between the MOR and density of the acetylated samples.For the samples exposed to a water-soak-drying cycle, the highest MOR, and lowest reduction of 14 % compared with the unexposed state, was obtained for the US-US samples, whereas all samples involving the acetylated wood showed a distinctly higher reduction. The MOR of the AJP-AJP and AJP-US samples were reduced with 47 % and 50 %, respectively, while the MOR of the APS-APS and APS-US samples were reduced with 43 % and 23 %, respectively. It should be emphasized, however, that after the standard drying-time, which was the same for all samples, the acetylated samples, compared with the untreated ones, did not dry out to the same level as for the dry unexposed state, i.e. the acetylated samples had a high MC of ca 30-40% in these MOR tests. This high MC level could be the main reason for the dramatic strength losses. Furthermore, a less efficient wood-MUF adhesion as well as the drying under acidic conditions may also be possible causes for the reduced bending strength of the finger-jointed samples with acetylated wood.

  • 206.
    Wålinder, M. E. P.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    EcoBuild – centrum för eko-effektiva träbaserade material och produkter. Samverkan mellan SP, 36 företag och universitet2009Konferensbidrag (Övrig (populärvetenskap, debatt, mm))
  • 207.
    Wålinder, M. E. P.
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Bryne, Lars-Elof
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Wood adhesion mechanisms: prediction of wood-thermoplastic-water interactions2006Ingår i: Wood Adhesives 2005 / [ed] Charles R. Frihart, Forest Products Society , 2006, nr 7230, s. 385-392Konferensbidrag (Refereegranskat)
  • 208.
    Wålinder, Magnus E. P.
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Englund, F.
    Technical Research Institute of Sweden.
    EcoBuild – a competence centre for eco-efficient and innovative wood-based materials: Message from the Manager2011Ingår i: EcoBuild Newsletter, Ed. Finn Englund, SP INFO 2011:55, nr 2, s. 1-1Artikel i tidskrift (Övrig (populärvetenskap, debatt, mm))
  • 209.
    Wålinder, Magnus E. P.
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Gardner, D.J.
    Surface energy characteristics of maple wood particles coated with polystyrene-acrylic acid (PSAA) block copolymer2011Ingår i: Proceedings of the 2011 IAWS Annual Meeting on Novel Materials from Wood or Cellulose, Stockholm: Innventia , 2011, s. 66-67Konferensbidrag (Refereegranskat)
  • 210.
    Wålinder, Magnus
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Larsson Brelid, Pia
    Segerholm, Kristoffer
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    II Long, C.
    Dickerson, J.P.
    Wettability of acetylated Southern yellow pine2013Ingår i: International Wood Products Journal, ISSN 2042-6445, Vol. 4, nr 3, s. 197-203Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The aim of this work was to achieve a better understanding of the wettability, i.e. liquids wetting and sorption characteristics (or penetrability), of acetylated Southern yellow pine (SYP) including probable differences in such characteristics between early- or latewood. Matched samples of acetylated and untreated SYP boards were prepared. The wettability of the samples were measured by the Wilhelmy technique using standard probe liquids as well as two different sample coatings, a cationic knot sealer and an acrylic based dye. The results showed that latewood regions of the acetylated wood had a noticeably lower uptake of the non-polar low surface tension liquid octane as well as the polar high surface tension liquid water compared with latewood of the untreated controls. Contact angle analysis based on the Lewis acid-base concept indicated that the acetylated wood is predominantly Lewis basic. A preferential wetting of the knot sealer was observed on the acetylated wood.

  • 211.
    Wålinder, Magnus
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Omidvar, A.
    Gorgan University, Gorgan, Iran.
    Seltman, J.
    SP Technical Research Institute of Sweden.
    Segerholm, Kristoffer
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Micromorphological studies of modified wood using a surface preparation technique based on ultraviolet laser ablation2009Ingår i: Wood Material Science & Engineering, ISSN 1748-0272, E-ISSN 1748-0280, Vol. 4, nr 1-2, s. 46-51Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The objective of this paper is to demonstrate an ultraviolet (UV) laser ablation technique as a tool for sample preparation in microscopy studies of modified wood. Improved techniques for studying the microstructure of modified wood are crucial for a deeper understanding of many of their physical, mechanical and durability properties. The surface preparation technique is described in this paper. An illustration of micrographs of the micromorphology and polymer distribution in some examples of modified wood is also presented. It is clearly demonstrated that in contrast to conventional surface preparation techniques used for light microscopy and scanning electron microscopy, i.e. razor blade and microtome cutting techniques, UV laser ablation does not introduce any mechanically induced microcracks and redistribution of polymers or other mobile substances in the prepared surface. Results also show that, in particular, this technique seems to be suitable for studying polymer distribution in resin-impregnated wood, as well as detection of microcracks in modified wood cell walls.

  • 212.
    Wålinder, Magnus
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Omidvar, Asghar
    Seltman, Joachim
    Segerholm, Kristoffer
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Micromorphology Studies of Modified Wood Using a Surface Preparation Technique Based on UV-Laser Ablation2009Ingår i: The Fourth European Conference on Wood Modification / [ed] F. Englund, C.A.S. Hill, H. Militz and B.K. Segerholm, 2009, s. 103-110Konferensbidrag (Refereegranskat)
  • 213.
    Wålinder, Magnus
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Segerholm, Kristoffer
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Larsson Brelid, Pia
    Westin, Mats
    Liquids and coatings wettability and penetrability of acetylated scots pine sapwood2010Ingår i: In Proceedings of the fifth European Conference on Wood Modification, ECWM5, 2010, s. 381-388Konferensbidrag (Refereegranskat)
  • 214.
    Wålinder, Magnus
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Segerholm, Kristoffer
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Söderström, Ove
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Water sorption properties and dimensional changes of high wood-content WPC2009Ingår i: Proceedings of the 5th meeting of the Nordic Baltic Network in Wood Material Science and Engineering / [ed] Andreas Bergstedt, 2009, s. 153-160Konferensbidrag (Refereegranskat)
    Abstract [en]

    The increased use of wood plastic composites (WPCs) for outdoor building applicationsis accompanied by an increased need for research about their durability properties. Oneparticularly important feature is their water sorption behaviour which relates to e.g. theirdimensional stability, mechanical properties and decay resistance. In this study, we haveinvestigated the water sorption ability and resulting dimensional changes of WPCs witha comparable high wood content, i.e. ca 70 weight-%, prepared with either a heattreated, acetylated or unmodified wood component. The experiments involve immersionof thin veneers of the composites in water with registration of their weight anddimensional changes until they have reached saturation. The results show that the WPCscontaining a modified wood component show the lowest level of water sorption anddimensional changes after saturation compared with the WPCs containing unmodifiedwood. A notably lower degree of a supposedly algae growth is also observed for thesamples with acetylated wood. One question that was generated during thisinvestigation relates to the density of the wood cell-wall and its relation to the appliedwood modification route and moisture uptake. The general conclusion regarding this isthat further studies are necessary to encompass such a topic, e.g. by more precisemeasurements of the wood cell-wall density in both dry and wet state.

  • 215.
    Wålinder, Magnus
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Segerholm, Kristoffer
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Westin, Mats
    Durability of high wood content WPCs2010Ingår i: Proceedings of the International Convention of Society of Wood Science and Technology andUnited Nations Economic Commission for Europe – Timber Committee, 2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    One increasing market segment of building materials is so-called biocomposites, or wood-thermoplastic composites (WPCs). Chiefly, these products are partly made from renewable resources such as wood residuals or agro fibres, functioning as reinforcement, and partly from recyclable thermoplastics or biopolymers, functioning as matrix. In general, WPC products are marketed as a low maintenance building material with a high outdoor durability. The intrinsic high moisture sensitivity of the wood component in combination with a low compatibility between the hydrophilic wood and hydrophobic thermoplastic may, however, result in poor long-term performance and outdoor durability. The objective of this paper is to recapitulate some of our research group’s observations and experience during recent years with respect to both field and laboratory tests related to the durability of WPCs. Of particular interest is one type of extruded WPCs with a comparable high wood content, i.e. ca 70 weight-%, prepared with either a heat treated, acetylated, or unmodified wood component. Observations from outdoor field trials, laboratory fungal decay tests, moisture sorption properties and effects on micromorphology, show that the use of a modified wood component in these WPCs considerably increases their long-term outdoor durability. One reason for this is related to the reduction of the moisture sensitivity of the wood component. Such durable biocomposite-type of building materials with a high wood-content level have the potential to fulfill the criteria for being eco-efficient, that is being both a sustainable and a cost-efficient “green” material.

  • 216.
    Yideti, Tatek
    et al.
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap.
    Jelagin, Denis
    KTH, Skolan för teknikvetenskap (SCI), Hållfasthetslära (Inst.), Hållfasthetslära (Avd.). KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Birgisson, Björn
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Transportvetenskap.
    Moisture Distribution Model to Predict Matric Suction in Unbound Granular Materials as a Function of Fines Content2016Ingår i: TRB 95th Annual Meeting Compendium of Papers, 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    The existence of water in the layers of unbound road aggregates significantly influences the performance of pavement structure. Thus, the ability to estimate volumetric water content and its capillary effect is very important. Several models have been suggested to link the matric suction of unbound materials to their water retention properties. In this paper, an analytical moisture distribution model is proposed by using packing theory-based framework for unbound granular materials. The framework was previously developed by the authors of this paper and identifies two basic components of unbound granular materials skeleton: primary structure (PS) - a range of interactive coarse grain sizes that forms the main load-carrying network in granular materials and secondary structure (SS) - a range of grain sizes smaller than the PS providing stability to the aggregate skeleton. In the new moisture model, water was considered to be stored as both menisci water between SS particles and water that fully filled in very small voids. In order to validate the model, predicted results are compared with measured matric suction of a granite material with different gradations. The results showed that the model is capable of predicting the experimentally measured matric suction values for a range of gradations.

  • 217.
    Zaccaro, Vito Lorenzo
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Timber-concrete hybrid innovations: A framework to evaluate economical and technical factors for the construction market2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Nowadays, the focus of the construction market is on sustainability aspects, for which purpose, the employment of wood seems promising. Nevertheless, in countries having high potentiality like Sweden, the timber construction market finds difficulties in growing. The reason lies in the lack of standards for design and industrialization and on the strong competition of the concrete industry. The timber-concrete hybrid solution is presented in this study as a solution beneficial for both the timber and the concrete markets: the former would benefit of a pulling action towards standardization and larger market, while the latter would fulfil the environment-friendly requirements and better differentiate in the competitive landscape.

    Therefore, the objective of this thesis is to provide a framework to evaluate innovations in construction market, highlighting the characteristic issues related to the matching of timber and concrete constructions, and detecting the main economic and technical factors to help in the decision-making process. This framework will help to organize and evaluate all the information and the boundary conditions about the introduction of a concrete-timber hybrid construction solution, which eventually would enhance the timber construction market itself through a preliminary association with concrete market.

    Firstly, some consideration on the market areas and on the general perceptions towards the timber construction are presented; then, the focus is moved onto the dynamics of concrete and timber supply chains, highlighting similarities, diversities, and possible reciprocal benefits, to finally detect the market indicators to be considered for a decision-making path related to the timber-concrete hybrid construction.

    From the technical side, a conceptual design is proposed, considering the industrialization of such hybrid solution. Annex A shows how standardization and modularity of the products would enable compatibility and interchangeability between timber and concrete, on account of the open system within the construction market. Annex B displays a schematic picture of how the exploitation of timber and concrete’ properties, with the industrialization of these two materials, can be best employed for a hybrid building. A preliminary technical evaluation of the timber-concrete hybrid is carried out by dividing the building into modular units and focusing on the main systems (horizontal loadbearing system, vertical loadbearing system, external envelope, inner partitions), while making consideration on structural design, fire protection, building technology details, building service systems integration, construction plan, and costs.

    The innovations within the construction market are often hindered by the fear to undertake a high-risk project. The proposed framework allows to increase the awareness on the general factors to be evaluated, and to undertake a gradual adoption of the “new” timber construction solution. The key points underlying the whole timber-concrete hybrid problem are standardization and modularity, necessary for a quality-oriented production. Further studies need to be carried out with an applicative intent: application of the general framework to real cases and pilot projects; automatic tools for the design and construction optimization including economic and technical factors; innovative and original hybrid solutions, which better exploit the timber-concrete synergy.

  • 218. Čermák, Petr
    et al.
    Vahtikari, Katja
    Rautkari, Lauri
    Laine, Kristiina
    KTH, Skolan för arkitektur och samhällsbyggnad (ABE), Byggvetenskap, Byggnadsmaterial.
    Horáček, Petr
    Baar, Jan
    The effect of wetting cycles on moisture behaviour of thermally modified Scots pine (Pinus sylvestris L.) wood2016Ingår i: Journal of Materials Science, ISSN 0022-2461, E-ISSN 1573-4803, Vol. 51, nr 3, s. 1504-1511Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The moisture behaviour of thermally modified Scots pine (Pinus sylvestris L.) exposed to cyclic conditions was analysed. Specimens of dimensions 15 × 15 × 5 mm3 were thermally modified at 180 °C (TM1) and 220 °C (TM2) using atmospheric pressure and superheated steam. Radial, tangential, volumetric swelling and anti-swelling efficiency (ASE) were calculated during six consecutive drying–soaking cycles. Afterwards, additional specimens were exposed to ten relative humidity cycles (0 and 95 %) at temperature 25 and 40 °C in order to analyse its influence on sorption behaviour. Application of thermal modification led to significant reduction of swelling from original 18.4–13.3 % for TM1 and to 10.5 % for TM2. However, after exposure to six consecutive soaking–drying cycles, the swelling of control specimens slightly decreased, whereas the swelling of thermally modified specimens increased. Due to the increased swelling after repeated cycles, the original ASE (28.6 and 42.7 %) decreased to 22.5 % for TM1 and to 36.88 % for TM2. The presence of leachable compounds and release of internal stresses are mainly attributed to that phenomenon. The EMC of the reference specimens decreases over the repeated humidity cycles for approximately 1 %–units. Same trend was found for the mild thermal modification TM1, but decreasing only in the range of 0.5 %–units. However, the EMC of the TM2 specimens during humidity cycles behaved differently. The results provide a better insight into details of thermal modification of wood and its behaviour under cyclic conditions.

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