11. |
- Mathern, Alexandre, 1986, et al.
(författare)
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Lessons learned from the construction, inspection, and defect assessment of reinforced concrete foundations for wind turbines
- 2022
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Ingår i: Applied Sciences (Switzerland). - : MDPI AG. - 2076-3417. ; 12:3
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Tidskriftsartikel (refereegranskat)abstract
- Foundations of wind turbines are subject to challenging conditions during their service life as they support ever larger wind turbines under complex loading situations. There have been numerous reports of cracked concrete foundations of wind turbines. Cracking can impair the durability and serviceability of the foundations, thereby leading to very expensive repairs or even to premature failure of the structure. To avoid cracking-related problems and improve the quality of concrete foundations, it is important to gather information and experience from the production stage and its outcome. However, although problems and defects in the construction of wind turbine foundations are widespread, they have very seldom been documented and reported, in particular from a contractor’s perspective. This article analyses and critically reviews data collected during the production, inspection, diagnosis, and repair activities conducted in relation to the construction of foundations for a wind farm project in Sweden. The extent of defects observed on individual foundations is assessed and used to investigate the eventual relation between the observed deviations and different production aspects. Investigation methods to determine the importance of these defects and their consequences and possible remediation measures are also discussed. Finally, recommendations are proposed to improve the quality control of wind turbine foundations.
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12. |
- Ask, Anna, et al.
(författare)
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Studenters uppmärksamhet under föreläsningar
- 2009
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Ingår i: Proceedings utvecklingskonferens 09 Lunds Universitet. - 9789197797429 ; , s. 112-120
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Konferensbidrag (refereegranskat)abstract
- Föreläsningar är vanlig undervisningsform på Lunds Tekniska Högskola (LTH). Deras stora fördel är att information överförs ekonomiskt och effektivt till många studenter samtidigt men de har även sina begränsningar. Kritiker menar att information överförs till passivt mottagande studenter och att bristande uppmärksamhet och engagemang hos studenterna begränsar mängden kunskap som faktiskt tas emot. En intervju- och litteraturstudie har genomförts för att dels inventera vilka metoder som finns för att hålla studenternas uppmärksamhet uppe och dels vilka som tillämpas av föreläsare vid LTH. Variation och olika former av aktivering framstår såväl i litteraturen som i intervjuerna som viktiga metoder. I artikeln presenteras även inspiration kring hur man kan använda variation, och andra aktiviteter för att engagera och aktivera studenterna samt hur man kan strukturera en föreläsning. De flesta av de intervjuade föreläsarna uppger att de utvecklat sina strategier genom erfarenhet medan knappt hälften nämner pedagogiska kurser.
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13. |
- Bournas, Iason, et al.
(författare)
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Energy renovation of an office building using a holistic design approach
- 2016
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Ingår i: Journal of Building Engineering. - : Elsevier BV. - 2352-7102. ; 7:September 2016, s. 194-206
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a holistic approach to perform energy renovations of office buildings. A real case study is used to demonstrate how different software can be used to facilitate the work of architects and engineers during different design stages. Initially, the moisture safety of the building is coupled to its energy performance to define the optimum insulation level. The new interior layout is based on an initial daylight study, rather than on architectural intuition. On a second stage, shading and natural ventilation are studied to eradicate any cooling demand, while the interdependence between heating energy and daylight is assessed for the use of light-wells. To demonstrate the trade-offs between visual control and electrical lighting, different shading systems are examined for a cellular office. Finally, two alternate HVAC systems are analyzed to investigate whether passive standards can be achieved with an all-air system and/or a hydronic system.
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14. |
- Crocetti, Roberto, et al.
(författare)
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Stress-laminated-timber decks: state of the art and design based on Swedish practice
- 2016
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Ingår i: European Journal of Wood and Wood Products/Holz als Roh - und Werkstoff. - : Springer Science and Business Media LLC. - 1436-736X .- 0018-3768. ; 74:3, s. 453-461
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Tidskriftsartikel (refereegranskat)abstract
- Stress-laminated-timber (SLT) bridge decks area valid alternative to conventional short- and medium-spanbridges in terms of cost and performance. SLT decks aremade from a number of planks or glulam beams positionedside by side and stressed together using high-strength steelbars. A concentrated load can therefore be distributed fromthe loaded beams onto adjacent beams due to the resistingfriction caused by the pre-stressing of all beams in thedeck. This paper describes the state of the art of SLT bridgedecks, with special emphasis on Swedish practice. Theeffect of butt joints on deck deflection and solution appliedto accommodate the loss of pre-stress are shown. Simpledesign tools for the preliminary design of road bridges areillustrated. Best practice with regard to some detailing,water protection and durability is also discussed. Finally,possible developments of SLT bridges are discussed.
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15. |
- Hagbert, Pernilla, 1986
(författare)
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Den gröna byggbranschens paradox
- 2013
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Ingår i: Att svära i kyrkan - tjugofyra röster om evig tillväxt på en ändlig planet. - 9789198146707 ; , s. 206-217
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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16. |
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17. |
- Silfwerbrand, Johan, et al.
(författare)
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Performance-based requirements in design-build contracting for highway construction and maintenance
- 2019
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Ingår i: FIB 2018 - Proceedings for the 2018 fib Congress. - : Federation Internationale du Beton (fib). ; , s. 470-478, s. 470-478
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Konferensbidrag (refereegranskat)abstract
- Design-build contracts with performance-based specifications are believed to raise productivity and the innovation rate. However, performance-based requirements used in specifications for highway and bridge contracts may suffer from being too detailed or too difficult to verify. A Swedish research project has been devoted to this issue. The aims were (i) to develop a definition of performance-based requirements and (ii) to evaluate performance-based requirements used in Swedish design-build contracts. The project consisted of three parts: (i) literature survey, (ii) investigation of current documents produced and used by the Swedish Transport Administration for design-build contracts, and (iii) case studies of six design-build contracts with performance-based requirements, including an analysis of specification documents and interviews with both client and contractor project managers. Current performance-based specifications show different degrees of detail. Measurable requirements are more frequently used on roads, and in particular on road surfaces, than on bridges. Further development is needed to promote technical innovations. Less detailed specifications and a shift to design-build-operate contracts with prolonged maintenance responsibility would also encourage the choice of more durable and long-lasting (=sustainable) solutions. The emphasis on Life Cycle Cost (LCC) in the reformulated contract award criteria in the EU public procurement directive might be insufficient to strengthen the competitive power of concrete pavements as compared to asphalt pavements, unless specifications are supported by Life Cycle Analysis (LCA) and the choice of contract type is reconsidered.
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18. |
- van Eldert, Jeroen, 1987-, et al.
(författare)
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Application of Measurement While Drilling Technology to Predict Rock Mass Quality and Rock Support for Tunnelling
- 2020
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Ingår i: Rock Mechanics and Rock Engineering. - : Springer. - 0723-2632 .- 1434-453X. ; 53:3, s. 1349-1358
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Tidskriftsartikel (refereegranskat)abstract
- A tunnelling project is normally initiated with a site investigation to determine the in situ rock mass conditions and to generate the basis for the tunnel design and rock support. However, since site investigations often are based on limited information (surface mapping, geophysical profiles, few bore holes, etc.), the estimation of the rock mass conditions may contain inaccuracies, resulting in underestimating the required rock support. The study hypothesised that these inaccuracies could be reduced using Measurement While Drilling (MWD) technology to assist in the decision-making process. A case study of two tunnels in the Stockholm bypass found the rock mass quality was severely overestimated by the site investigation; more than 45% of the investigated sections had a lower rock mass quality than expected. MWD data were recorded in 25 m grout holes and 6 m blast holes. The MWD data were normalised so that the long grout holes with larger hole diameters and the shorter blast holes with smaller hole diameters gave similar results. With normalised MWD data, it was possible to mimic the tunnel contour mapping; results showed good correlation with mapped Q-value and installed rock support. MWD technology can improve the accuracy of forecasting the rock mass ahead of the face. It can bridge the information gap between the early, somewhat uncertain geotechnical site investigation and the geological mapping done after excavation to optimise rock support.
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19. |
- Desivyana, Nindya, 1997, et al.
(författare)
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Sustainability Driven Procurement of Building Projects Incentives and Driving Factors from the Clients’ Perspective
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The construction industry is reported as one of the biggest global industries which accounted 30% global greenhouse gas emissions. The challenge of the construction industry is not merely on the reduction of emissions, but also extended towards other aspects of sustainability, consisting of the environmental, social, and economic pillars of sustainability. Sweden took action to handle the environmental issues by targeting on being climate neutral by 2045. Hence, the Swedish National Board of Housing, Building, and Planning, commonly known as Boverket, took more detailed action by stipulating climate declaration for all new buildings. The property developers play a vital role to boost sustainability in Sweden, since they have an increased influence in the hierarchy of the construction industry. In this case, the drivers of sustainable development in the construction industry are partially reliant on the clients’ requirements requested in every project, as well as their ethics and initiatives. Therefore, this study investigates the state-of-the-art sustainable practices among property developers in Sweden to identify the main challenges in applying sustainable criteria during the procurement phase. This study was carried out by qualitative research which consists of a literature review and an empirical study of semi-structured interviews. This study resulted in the identification of several common sustainable criteria, covering the three pillars of sustainability and also emphasising the fact that currently the property developers have an increased interest in environmental and economic sustainability, rather than social sustainability. The results of the study also raised the notion of long-term perspective, how it affects the business strategy on sustainability and the different perceptions that exist. The study concludes that the market demand drives the implementation of the agenda on sustainability, among property developers in Sweden, while providing substantial information that could prove useful in the future development of the national agenda and its regulations.
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20. |
- Hagbert, Pernilla, 1986
(författare)
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Byggbranschens gröna paradox
- 2013
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Ingår i: Archileaks redaktionella material, archileaks.se.
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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