| 1. |
- Nord, Tomas, 1966-, et al.
(författare)
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Role of Policies and National Programmes on Innovations in Timber-frame Construction
- 2011
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Ingår i: Innovation in Forestry. - Wallingford, UK : CAB International. - 9781845936891 ; , s. 204-232
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Bokkapitel (refereegranskat)abstract
- The market share of timber frame construction has increased in many European countries after the revision of national building regulations, implementation of national development programs as well as marketing efforts of the forest industry. Our research within COST E51 has looked at the timber construction industry and assessed the innovation process in eight European countries,the role and position of this industry in the construction process, and the influence of policies as drivers of knowledge creation.Results indicate that innovative timber construction firms have acted on the changed regulations overcoming the lock-in effects of construction industry standards and culture and have in some countries been in the forefront to adjust the traditional construction process. These firms have in most cases come from the forest industry sector as they have had the most to gain. The innovation type and progress differ indicating that construction is a local activity influenced by national traditions,both in industry behaviour and policy aim. It is recommended that policy makers support the establishment of local and regional timber based competence centres. Also,public construction clients ought to have bigger leeway to support innovative construction products and processes, as a mean to generating new innovations, knowledge creation and transfer necessary to create a sustainable future society.
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| 2. |
- Nord, Tomas, et al.
(författare)
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Role of policies on innovations in timber frame construction : Cases from sub-group Timber construction vertical value chain in COST Action E51 Integrating Innovation and Development Policies for the Forest Sector
- 2010
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The enlargement of EU coupled with harmonization of regulations and standards have opened new market segments and geographical areas resulting in grown market shares and innovative behaviour of timber construction firms. The role of policies aiming at increased competitiveness and innovativeness of the European forest sector through integrating innovation has been studied within a COST Action running from 2006 to 2010. COST Action E51 "Integrating Innovation and Development Policies for the Forest Sector" aimed at increasing our understanding of the role of policies and development programs to improve competitiveness and specifically innovations in the forest sector. One of the sub-groups studied the timber construction value chain and the type and diffusion of innovations. This report presents empirical data of timber construction industries from eight European countries. The data include the general construction environment and the policy superstructure of each country and one characteristic example of innovation and innovation process within the timber construction industry of each country respectively. The description of the construction industry follows the concept that construction is a complex product system (CoPS, Hobday, 1998) relating actors in an innovation system approach manner. The timber construction industry is gradually moving from supplier to system integrators thus modifying the overall system.The results indicate a large difference between studied industries in terms of type of innovation, supportive actions from society and industry organizations, and the effect of the innovation on the overall building process and infrastructure.
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| 3. |
- Tykkae, Saana, et al.
(författare)
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Development of timber framed firms in the construction sector - Is EU policy one source of their innovation?
- 2010
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Ingår i: Forest Policy and Economics. - : Elsevier. - 1389-9341 .- 1872-7050. ; 12:3, s. 199-206
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Tidskriftsartikel (refereegranskat)abstract
- To enhance competition in the construction industry, EU policies have created and harmonised functional building codes. Moreover, many actors advocate the construction industry moves towards a lean production, process-based way of working for quality and cost reasons. Here, Timber Framed Engineering approaches are considered to have a competitive and environmental advantage. There is however underlying concerns that conservatism in the construction industry, and lack of timber engineering skills, may be obstacles to change. This paper therefore assesses whether EU construction policy innovation contributed to innovation at the firm level. Timber framed innovators in six European countries were identified, and their sources of innovation assessed. The results indicate that timber framed firms have become actors in the construction industry. Firms have made product, process and organisation innovations. All case firms have similar sources for innovation. The common factor that triggers the firms to innovate is business opportunities that arise from demographic changes in the environment outside the firm, such as environmental sustainability and affordable housing for lower income groups. To address these opportunities, the case firms implicitly recognised that traditional project and site-based construction approaches are an incongruity. The firms have consequently established in-house prefabrication, including developed of lean production processes to ensure quality as well as effectiveness. The firms have all recognised that a fundamental barrier to their business was the lack of timber framed engineering competencies in their customers organisations. Accordingly, a business necessity for the case firms was developing construction design competencies. Firms benefited from governmental policy instruments that support timber framed Randamp;D and knowledge transfer. However, firms also gained new knowledge from their own experiences, which they also use in their operations. Accordingly, policy instruments are not a sole or dominant source for innovation in the case firms. Nonetheless, the change in building codes has been a pre-requisite the firms commercial developments.
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| 4. |
- Alen, Malagic, et al.
(författare)
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Reinforced notched cross-laminated timber plates : Load-bearing capacity and methodology for predicting the force in reinforcement
- 2023
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Ingår i: Proceedings from the 13th World Conference on Timber Engineering (2023). - 9781713873273 - 9781713873297 ; , s. 2442-2453
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Konferensbidrag (refereegranskat)abstract
- This paper deals with the estimation of the design force in self-tapping screws used as a reinforcement ofnotched cross laminated timber plates (CLT). With the reinforcement, apart from an increased load-carrying capacity, amore ductile behaviour of this detail can be achieved. An analytical model based on the Timoshenko Beam Theory wasdeveloped, enabling the estimation of the axial force in the reinforcement. A parametric numerical analysis was conductedto verify the model and to provide possible ways for the calibration. The results show a good matching of the model withthe numerical results. The load-bearing capacity is analysed using a simple fracture mechanics model taking intoconsideration the effect of the reinforcement to correctly depict the increase in performance. Theoretical and numericalresults are compared with experimental findings and show acceptable correlations encouraging a further development anda subsequent implementation in EN 1995-1-1.
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| 5. |
- Azinović, Boris, et al.
(författare)
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INNOCROSSLAM : Adding knowledge towards increased use of cross laminated timber (CLT)
- 2023
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Ingår i: Proceedings from the 13th World Conference on Timber Engineering (2023). - 9781713873273 - 9781713873297 ; , s. 2432-2441
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Konferensbidrag (refereegranskat)abstract
- The research project Innovative Solutions for Cross Laminated Timber Structures (InnoCrossLam) wasrecently finished. The project aimed at increasing the competitiveness of CLT as a versatile engineered product, byincreasing its predictability in demanding design situations not covered by the guidelines of today, or standards and codesforeseeable in the near future (e.g., second generation of European design standards). This paper summarises the mainproject findings in the context of innovative CLT structures, such as: i. contemporary design approaches ii. the use of(non)linear FE modelling iii. experimental investigation of complex details for CLT structures, iv. investigation ofmultifunctional CLT. In this paper, the motivation behind the research topics within the project InnoCrossLam isexplained and backed-up by exemplary results and discussion on future work.
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| 6. |
- Danielsson, Henrik, et al.
(författare)
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Shear failure mechanism III in cross laminated timber : Numerical investigations of fracture behaviour
- 2023
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Ingår i: Proceedings from the 13th World Conference on Timber Engineering (2023). - 9781713873273 ; , s. 2396-2405
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Konferensbidrag (refereegranskat)abstract
- The paper deals with numerical investigations of load-bearing capacity and fracture behaviour of CrossLaminated Timber at in-plane shear loading. Focus is on shear failure mechanism III, i.e. failure in the crossing areasbetween flatwise bonded laminations, and on evaluating test methods for that failure mode. In current design provisions,this failure mode is characterised by the rolling shear strength, fv,R , and the torsional shear strength, fv,tor , and thereforetesting including both transverse (rolling) shear and torsional shear is needed. Two such test set-ups are investigated, oneaiming at evaluating torsional shear strength and one aiming at evaluating rolling shear strength. Full 3D finite elementanalyses applying a cohesive zone model approach were used to study the strength and fracture behaviour. Failure criteriafor structural design, material strength parameters, and the suitability of the two test configurations to determine strengthparameters are discussed in relation to findings from the numerical investigations. One main conclusion from theinvestigation is that expected test results using the torsional test set-up are less size dependent as compared to test resultsusing the transverse set-up. The numerical analyses suggest a very small influence from tensile loading perpendicular tothe crossing area, for both test set-ups.
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| 7. |
- Mohaine, Siyimane, et al.
(författare)
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PERFORMANCE OF PASSIVE PROTECTION OF CROSS LAMINATED TIMBER DURING STANDARD FURNACE TESTS AND NATURAL FIRES
- 2023
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Ingår i: 13th World Conference on Timber Engineering, WCTE 2023. - 9781713873297 ; 3, s. 1839-1847
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Konferensbidrag (refereegranskat)abstract
- This paper presents the results of an experimental campaign designed to compare and understand the performance of passive protection under exposure to standard furnace tests and natural fires. As part of this campaign, five natural fire experiments were performed with partially protected cross-laminated timber (CLT) compartments under a range of ventilation conditions. In all the tests, only one side wall was left completely unprotected, and all other timber surfaces were protected with either two layers of 18 mm standard gypsum boards (GB) or two layers of 25 mm standard GBs. The structural CLT ceilings were subjected to a superimposed dead load of 1.35 kN/m² during the natural fire tests, and the fire load was (on average) 950 MJ/m²; chosen to represent the Eurocode 1991-1-2 characteristic value for dwellings. The performance of the passive protection was mainly evaluated with regards to the time to reach a protected timber surface temperature of 250°C. The testing confirms that the resulting fire protection performance of a given gypsum board layout depends on the ventilation conditions of the fire compartment, with more severe (and closest to ISO testing) outcomes when testing under ventilation-controlled scenarios. This paper provides data that sheds light on the co-dependency of the passive protection design and compartment fire dynamics and underlines the importance of considering the safety objectives of a building when defining the performance criteria of its structural elements.
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| 8. |
- Nore, Kristine, et al.
(författare)
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Moisture buffering, energy potential, and volatile organic compound emissions of wood exposed to indoor environments
- 2017
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Ingår i: Science and Technology for the Built Environment. - : Informa UK Limited. - 2374-4731 .- 2374-474X. ; 23:3, s. 512-521
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Tidskriftsartikel (refereegranskat)abstract
- The use of wood in built environments has been increasing during the last decades, and more focus has been set on the influence of wood surfaces on indoor environments on the objective and subjective measures of human well-being. In addition, the moisture buffer capacity of hygroscopic materials, such as wood, has been under investigation in order to quantify the impact of wooden surfaces on energy savings in buildings. The current study presents the results of wood surfaces and indoor air temperatures as well as indoor air relative humidity measured in two solid timber test houses. The findings reveal a substantial effect on wood surface temperature under fluctuating indoor relative humidity due to the latent heat of sorption of water vapors. The results were compared with hygrothermal numerical simulations, showing good agreement and the validated numerical model was used in order to quantify the energy performance in a bathroom when the latent heat of sorption is exploited. The combination of wood with a well-controlled HVAC system in rooms with moisture production shows significant potential for indirect energy savings by adjusting the indoor temperature and exploiting the increase of surface temperature in the hygroscopic structure. Furthermore, the emissions of volatile organic compounds from pine wood were studied in laboratory facilities, with focus on the variations of emissions due to diurnal fluctuations in air humidity. Human participants were exposed in a large test chamber to a concealed source of volatile organic compound emissions in the form of fresh pine wood, while the actual exposure reached air levels of monoterpenes up to 18 mg/m3 during the intervention situation. Perceptions of air quality and mucosal irritation effects were reported in a standard questionnaire during this double-blind test with no irritation effects reported.
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