| 1. |
- Desivyana, Nindya, 1997, et al.
(författare)
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Challenges in the adoption of sustainable criteria in the Swedish property development industry
- 2023
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Ingår i: Procedia Computer Science. - : Elsevier BV. - 1877-0509. ; 219, s. 1752-1759
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Konferensbidrag (refereegranskat)abstract
- The construction industry is facing an increased focus on sustainability and climate neutrality, causing property developers to implement new requirements into the procurement documents, which are also driven by the national agenda. This study explores the current state of sustainability practice among Swedish property developers and identifies the main obstacles to expand further the implementation of the sustainability criteria. How the property developers define and implement sustainability requirements has been assessed through qualitative semi-structured interviews, focusing on sustainability certification systems, Life Cycle Assessment (LCA), and social sustainability. The results show usage of sustainability certification systems for marketing purposes and high awareness and practice of LCA, even though the accuracy of LCA was questioned. This study also identified guideline gaps for circular economy and social sustainability measurements, which could relate to low initiatives from the certification systems.
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| 2. |
- Rempling, Rasmus, 1976, et al.
(författare)
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Utmattning
- 2021
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Ingår i: Betonghandbok material - Hårdnad betong, fysikaliska egenskaper och beständighet. - 9789179170882 ; , s. 485-510
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Bokkapitel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Mathern, Alexandre, 1986
(författare)
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Addressing the complexity of sustainability-driven structural design: Computational design, optimization, and decision making
- 2021
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Being one of the sectors with the largest environmental burden and high socio-economic impacts sets high requirements on the construction industry. At the same time, this provides the sector with great opportunities to contribute to the globally pursued sustainability transition. To cope with the increasing need for infrastructure and, at the same time, limit their sustainability impacts, changes and innovation in the construction sector are required. The greatest possibility to limit the sustainability impact of construction works is at the early design phase of construction projects, as many of the choices influencing sustainability are made at that point. Traditionally, an early choice of a preferred design is often made based on limited knowledge and past experience, considering only a handful of options. This preferred design is then taken on to the successive stages in the stepwise design process, leading to suboptimization. Alternatively, many different design choices could be considered and evaluated in a more holistic approach in order to find the most sustainable design for a particular application. However, finding design solutions that offer the best sustainability performance and fulfil all structural, performance and buildability requirements, require methods that allow considering different design options, analysing them, and assessing their sustainability. The aim of this thesis is to explore and develop methods enabling structural engineers to take sustainability objectives into account in the design of structures. Throughout this thesis, a number of methods have been explored to take sustainability aspects into account in the structural design process. As a first step, highly parameterized computer codes for sustainability-driven design have been developed. These codes interoperate with FE analysis software to automatically model and analyse design concepts over the whole design space and verify compliance with structural design standards. The codes were complemented with a harmonized method for life cycle sustainability performance assessment, in line with the state-of-the-art standards. Here, sustainability criteria were defined covering environmental, social, economic, buildability and structural performance for multi-criteria assessment of design concepts. To identify the most sustainable designs within the set, multi-objective optimization algorithms were used. Algorithms that address the high expense of constraint function evaluations of structural design problems were developed and integrated in the parameterized computer codes for sustainability-driven design. To ensure the applicability and validity of these methods, case studies based on real-world projects and common structural engineering problems were used in this thesis. Case studies for bridges and wind turbine foundations as well as a benchmark case of a reinforced concrete beam were investigated. The case studies highlight the potential of the methods explored to support the design of more sustainable structures, as well as the applicability of the methods in structural engineering practice. It is concluded that it is possible and beneficial to combine computational design, life cycle sustainability assessment, and multi-objective design optimization as a basis for decision making in the design phase of civil engineering projects. A wide adoption of such a sustainability-driven design optimization approach in structural engineering practice can directly improve the sustainability of the construction sector.
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| 4. |
- Mathern, Alexandre, 1986, et al.
(författare)
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Concrete Support Structures for Offshore Wind Turbines: Current Status, Challenges, and Future Trends
- 2021
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Ingår i: Energies. - : MDPI AG. - 1996-1073 .- 1996-1073. ; 14:7
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Forskningsöversikt (refereegranskat)abstract
- Today’s offshore wind turbine support structures market is largely dominated by steel structures, since steel monopiles account for the vast majority of installations in the last decade and new types of multi-leg steel structures have been developed in recent years. However, as wind turbines become bigger, and potential sites for offshore wind farms are located in ever deeper waters and ever further from the shore, the conditions for the design, transport, and installation of support structures are changing. In light of these facts, this paper identifies and categorizes the challenges and future trends related to the use of concrete for support structures of future offshore wind projects. To do so, recent advances and technologies still under development for both bottom-fixed and floating concrete support structures have been reviewed. It was found that these new developments meet the challenges associated with the use of concrete support structures, as they will allow the production costs to be lowered and transport and installation to be facilitated. New technologies for concrete support structures used at medium and great water depths are also being developed and are expected to become more common in future offshore wind installations. Therefore, the new developments identified in this paper show the likelihood of an increase in the use of concrete support structures in future offshore wind farms. These developments also indicate that the complexity of future support structures will increase due to the development of hybrid structures combining steel and concrete. These evolutions call for new knowledge and technical know-how in order to allow reliable structures to be built and risk-free offshore installation to be executed.
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| 5. |
- Rempling, Rasmus, 1976, et al.
(författare)
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Performance requirements for Swedish transport infrastructure - A pre-study of challenges and possibilities
- 2022
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- In recent years, significant worldwide research has been conducted regarding the performance assessment of bridges and the concept of performance indicator has been introduced However, there are still significant discrepancies in how these indicators are obtained and used. Simultaneously, it is desirable to achieve processes and methods that are direct, i.e. that measured values are directly compared with projected values over time. This project concerns methods for verification of technical performance requirements. The feasibility study brought together interdisciplinary researchers, consultants, and entrepreneurs to gather knowledge, anchor the research agenda, and implement performance requirements. The project concludes that there is a need for a “Holistic multi-parameter verification/validation system” that relies on the knowledge gained in structural health monitoring research.
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| 6. |
- 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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| 7. |
- 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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| 8. |
- 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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| 9. |
- Löfgren, Simon
(författare)
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Set-Based Design of Frame Bridges - Development and Implementation
- 2020
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The traditional design process of bridges in structural engineering is based on the design approach called Point-Based design. To minimize environmental impact and industrialize the design process, the theory of Set-Based design (SBD) has been recognized as a promising approach. Since frame bridges is one of the most common bridge types in Sweden, the main objective of this thesis is to develop and implement a SBD tool for frame bridges. To be able to evaluate the different design alternatives generated by the design tool, evaluation criteria within buildability and sustainability are identified. Buildability is a concept within building industry that aims to improve productivity and safety within on-site production while also reducing the costs of the construction process. The building industry is one of the major contributors regarding impact on its surrounding. Therefore, there is a huge potential in improving the sustainability within the building industry. Sustainability is divided in Environment, Social and Economy aspects. The design tool allows performing an automated and iterative structural preliminary design of several frame bridge alternatives specified within ranges of design parameters. The design alternatives are analyzed with Finite Element Analysis (FEA) and evaluated according to predefined evaluation criteria. By scripting the design tool in programing language Python, it is possible to control an FEA program, such as Brigade Plus, from the design tool as well as performing a preliminary design of frame bridges. The preliminary design is performed according to requirements in national building codes, Eurocode. Finally, a case study is performed to investigate how a SBD tool can be implemented in an infrastructure project containing several frame bridges. In a large infrastructure project and with a SBD tool it is possible to find one optimum bridge solution that fulfills the need of several bridges in a set of bridges. The contractor can then industrialize parts of the construction of frame bridges, hopefully leading to a more sustainable and cost-effective building of frame bridges.
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| 10. |
- 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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