| 1. |
- Dyrssen, Catharina, 1949, et al.
(författare)
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Key urban projects: Local-regional planning tools for fragile urban landscapes
- 2014
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Ingår i: World in Denmark 2014: Nordic encounters. Travelling ideas about open space design and planning.
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Konferensbidrag (refereegranskat)abstract
- In Sweden, cities are promoted as drivers of economic growth and solutions for decreased climatic influence, resulting in a dominant focus on development of large cities in the planning debate and sustainability discourse. As discussed by Harvey (2006), Massey (2007) and Tietjen (2011), this increases differences between growing and declining cities and regions, and escalates uneven geographic development. The process produces fragile urban landscapes, i.e. local situations short of resources, skills and mandates to handle change and deal with in-lock of sense-making structures, thereby concealing actual site specific possibilities and the potential of development of small towns and rural areas. This renders the need for new relevant planning tools with onset in a relational perspective on space (Harvey 2006, Massey 2007), urban ecologies (Guattari 1989, Banham 1971) and design-based, proformative approaches (Solà Morales 2008, Bunschoten 2001, Cuff & Sherman 2011). This article argues for key urban projects as a relational, place-specific, operative planning tool that can open and lock urban transformation, secure and guide implementation and reveal strategies to develop fragile urban landscapes, with ability to: handle centre-periphery and urban-rural as dynamic contingencies; combine the capacity of different urban ecologies; relate the formation of urban landscapes to different scales; optimise combinatory potentials of local-regional resources; secure forms of operative collaboration; trigger critical negotiations; and integrate spatial implementation to the planning process.These abilities are tested through design-based research-methodology with onset from works in progress in five Swedish contexts of practice that outline a spectrum of important characteristics of fragile urban landscapes.Key Urban Projects are identified and developed through a mapping process iterating between identification of specific issues and the outline of their relevant contours, a process that both visualize and establish assemblages (DeLanda 2006). Key Projects gain their potential through stepwise change of the existing material landscape and its urban ecologies.
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| 2. |
- 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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| 3. |
- Jockwer, Robert, 1984, et al.
(författare)
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Design for adaption - making timber buildings ready for circular use and extended service life
- 2021
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Ingår i: World Conference on Timber Engineering 2021, WCTE 2021.
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Konferensbidrag (refereegranskat)abstract
- The use of timber and the implementation of the concept of circularity in the process of the construction of buildings potentially has a high sustainability impact, both from the perspective of material and construction technique. The three most effective ways to ensure the benefit of the circularity in the building sector in general are (1) maintain the service life of structures and buildings materials as long as possible to avoid unnecessary emissions and costs for demolition and reconstruction (2) conserve the quality of materials as long as possible to avoid unnecessary emissions and costs for the replacement and processing of new materials and (3) recycle and repurpose only the parts and materials which cannot function any more for technical and/or socio-cultural reasons. In this paper an approach is discussed towards a more sustainable built environment by making buildings adaptable to the changes of demands and requirements to building functions and thus leading to an extended use of buildings in a maximum of life cycles. This design for adaption may enhance economic, social and environmental benefits to various stakeholders and key players related to the building process, i.e. developers, building owners, users, municipality and others.
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| 4. |
- Täljsten, Björn, 1961-, et al.
(författare)
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Assessment of prestressed concrete bridges - challenges
- 2020
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Ingår i: IABSE Symposium, Wroclaw 2020. - Zürich : International Association For Bridge And Structural Engineering (IABSE). ; , s. 487-494
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Konferensbidrag (refereegranskat)abstract
- Prestressed concrete bridges are important parts of our infrastructure. They are susceptible to different kinds of deterioration processes. Examples of damages and deficiencies are cracking, corrosion, voids, bond loss, reduction of cover layer, delamination, fatigue and loss of stiffness and strength. This necessitates methods to continuously assess their condition in order to avoid problems that might lead to shorter service life or reduction of structural integrity. Many of the existing prestressed bridges in Europe are now approaching their design life length. However, with proper and continuous inspection, monitoring and assessment, we may plan proactive maintenance and the structural safety can be assured or – if necessary - increased. This will save both money and decrease the environmental impact of the structure.
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| 5. |
- Armesto Barros, Jesús, et al.
(författare)
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Recent and future trends of onshore wind turbine foundations
- 2022
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Ingår i: Proceedings of the IABSE Symposium Prague 2022: Challenges for Existing and Oncoming Structures. - 9783857481819
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Konferensbidrag (refereegranskat)abstract
- The decarbonization of the economy and the growing need for electricity are two trends that call for greener energy sources. Wind is a growing renewable energy source, which is expected to become the first source of power in the European Union in the next decade. In particular, onshore wind energy is expected to double by then. Fundamental structural components of wind turbines are their foundations, which are large structures associated with important material consumption and many construction challenges. The dimensions of these foundations are continuously increasing as turbines with taller towers and larger rotor diameters are being built. Designing cost- and material-efficient foundations is crucial to reduce the economic and environmental impact of wind energy. An important factor to successfully address these evolving requirements in the planning and design process is to build on the experience from previous projects. The aim of this work is to investigate the evolution of onshore wind turbines and its consequences on the design and climate impact of gravity foundations by analysing data from Swedish wind farms set in operation between 2013 and 2022. The evolution of turbine size, and foundation dimensions, reinforcement layout, material types and quantities, and embodied carbon are analysed in this paper.
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| 6. |
- Bergenram, Felicia, et al.
(författare)
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Parametric Optimization of Slab Frame Bridges Considering Investment Cost, Environmental Impact and Buildability
- 2023
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Ingår i: Procedia Computer Science. - 1877-0509.
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Konferensbidrag (refereegranskat)abstract
- This paper presents research performed on set-based multi-criteria optimization for the preliminary design of slab frame bridges. As a result of immense CO2 emissions emerging from concrete production, there is a need for optimization methods decreasing the volume of concrete without affecting the function of the structure. Previous research suggests a general correlation between CO2 footprint- and cost reduction, due to minimized material use. However, the aspect of buildability may conflict with lessened material, as optimized designs might simultaneously be less buildable. This research aimed to develop an optimization method with respect to the investment cost and environmental impact while also considering buildability cost aspects. The optimization algorithm shows the possibilities of reducing the environmental impact by up to 13.7% for a slightly increased cost of 2.3%. Thus, by implementing optimization procedures in the early stages of the planning process the holistic cost effects related to green solutions can be presented, favoring the choice of sustainable designs amongst clients during tendering procedures.
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| 7. |
- Ek, Kristine, 1975, et al.
(författare)
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Multi-criteria decision analysis methods to support sustainable infrastructure construction
- 2019
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Ingår i: IABSE Symposium, Guimaraes 2019: Towards a Resilient Built Environment Risk and Asset Management - Report. ; , s. 1084-1091
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Konferensbidrag (refereegranskat)abstract
- The construction of infrastructure projects represents a large sustainability impact, both positive and negative. Increased positive and reduced negative impacts can be achieved through better design and planning of the construction. To make more sustainable choices, well‐defined predictive sustainability assessment methods are required. Multi‐criteria decision analysis (MCDA) is a well-suited method for predictive sustainability assessment. This paper evaluates two MCDA methods for sustainability assessment of infrastructure construction and exemplifies their application with two case studies. The aim of this paper is to discuss if the methods are suitable for identifying the most sustainable alternative during the procurement process of an infrastructure project. It is recommended that MCDA methods are further developed to comply with the recently published EN standard on sustainability assessment of civil engineering works.
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| 8. |
- Kiamili, Christina, et al.
(författare)
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Detailed Assessment of Embodied Carbon of HVAC Systems for a New Office Building Based on BIM
- 2020
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 12:8
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Tidskriftsartikel (refereegranskat)abstract
- The global shift towards embodied carbon reduction in the building sector has indicated the need for a detailed analysis of environmental impacts across the whole lifecycle of buildings. The environmental impact of heating, ventilation, and air conditioning (HVAC) systems has rarely been studied in detail. Most of the published studies are based on assumptions and rule of thumb techniques. In this study, the requirements and methods to perform a detailed life cycle assessment (LCA) for HVAC systems based on building information modelling (BIM) are assessed and framed for the first time. The approach of linking external product data information to objects using visual programming language (VPL) is tested, and its benefits over the existing workflows are presented. The detailed BIM model of a newly built office building in Switzerland is used as a case study. In addition, detailed project documentation is used to ensure the plausibility of the calculated impact. The LCA results show that the embodied impact of the HVAC systems is three times higher than the targets provided by the Swiss Energy Efficiency Path (SIA 2040). Furthermore, it is shown that the embodied impact of HVAC systems lies in the range of 15–36% of the total embodied impact of office buildings. Nevertheless, further research and similar case studies are needed to provide a robust picture of the embodied environmental impact of HVAC systems. The results could contribute to setting stricter targets in line with the vision of decarbonization of the building sector.
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| 9. |
- Larsson, Bengt, 1943-, et al.
(författare)
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The Effect and Cost Impact of Poor Airtightness : Information for Developers and Clients
- 2007
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Ingår i: Thermal Performance of the Exterior Envelopes of Whole Buildings. - Orlando : ASHRAE. - 2166-8469. - 9781933742281
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Konferensbidrag (refereegranskat)abstract
- Air movements in and through the building envelope affect the flows of not only heat, but also moisture, gases and particles, in a building. They often play a decisive part in determining moisture conditions, and thus indoor environmental conditions in the building, and ultimately, the durability of the building structure. Air flows affect thermal comfort and ventilation, and thus air quality. In addition, they also cause heat loss, both directly via ventilation, and through their effect on the performance of what are intended to be high-insulation structures.A previous joint project between SP Technical Research Institute of Sweden and Chalmers University of Technology investigated the importance of airtightness in the construction process. The project found that many types of damage and problems were caused by poor airtightness, that airtightness was seldom given the proper consideration that it deserved and that there was a major need for information on the effect of poor airtightness. One of the conclusions was that it is important to get developers/clients to treat airtightness more seriously.The objective of the follow-on project that is described here is therefore to make developers/clients (more) aware of the potential damage that can be caused by poor airtightness, together with the “cost” of this damage/problem in a life-cycle perspective. Hopefully, developers/clients will then specify and monitor airtightness requirements more clearly. The aim is therefore to develop tools and methods for informing developers/clients of the importance of good airtightness, and of the resulting extra costs that incur from paying insufficient attention to airtightness.The project has identified and assessed various consequences of poor airtightness, such as increased energy use, reduced thermal comfort, reduced air quality and moisture damages.The cost calculations show that the developer/client would benefit in most cases from an increased standard and follow up on airtightness. We have projected the work with three different levels of ambition: 0.2, 0.4 and 0.6 l/m2s (at 50 Pa pressure difference), and believe that the optimal airtightness lies somewhere in the region of these values, depending on the buildings use and equipment.
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| 10. |
- Mangold, Mikael, 1982, et al.
(författare)
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Building ownership, renovation investments, and energy performance - A study of multi-family dwellings in Gothenburg
- 2018
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Ingår i: Sustainability. - : MDPI AG. - 2071-1050. ; 10:5
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Tidskriftsartikel (refereegranskat)abstract
- The European building stock was renewed at a rapid pace during the period 1950-1975. In many European countries, the building stock from this time needs to be renovated, and there are opportunities to introduce energy efficiency measures in the renovation process. Information availability and increasingly available analysis tools make it possible to assess the impact of policy and regulation. This article describes methods developed for analyzing investments in renovation and energy performance based on building ownership and inhabitant socio-economic information developed for Swedish authorities, to be used for the Swedish national renovations strategy in 2019. This was done by analyzing measured energy usage and renovation investments made during the last 30 years, coupled with building specific official information of buildings and resident area characteristics, for multi-family dwellings in Gothenburg (N = 6319). The statistical analyses show that more costly renovations lead to decreasing energy usage for heating, but buildings that have been renovated during the last decades have a higher energy usage when accounting for current heating system, ownership, and resident socio-economic background. It is appropriate to include an affordability aspect in larger renovation projects since economically disadvantaged groups are over-represented in buildings with poorer energy performance.
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