| 1. |
- Mathern, Alexandre, 1986, et al.
(författare)
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Flexible assembly methods
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- There is today an increasing need for replacement of bridges in Europe due to aging infrastructures and increasing traffic. A large proportion of these bridges is located in urban environment or on important traffic routes, sensitive to nuisances such as noise and vibrations or to traffic disruptions, which are frequently inherent in construction works.In this context, PANTURA project aims to equip authorities and other stakeholders with methods, tools and techniques to enable bridge construction to be carried out in the most efficient and sustainable way. One of the means to reach this goal is through the improvement of off-site production and on-site construction processes.A wide range of technical solutions from prefabrication, ICT and robotics have been identified in this study. Many of these solutions or the materials they are based on are commonly used in production and manufacturing in other industries but scarcely in construction. Others have already been applied with success in civil engineering projects in some countries and would deserve wider diffusion. By analysing different innovative solutions using the SWOT approach, strategies have been presented to overcome their remaining weaknesses and to gain acceptance for them by the different actors of civil infrastructure projects.The use of prefabricated elements produced off-site and transported to the bridge site for assembly can be beneficial in terms of costs, construction time and social impact. Nevertheless, it sets high requirements on the assembly process. When using prefabricated elements flexibility decreases compared to traditional on-site bridge construction and late changes become harder to implement, therefore requiring a good planning to have an even flow at the site and to avoid unexpected events. With that in mind, the different stages of the assembly process have been studied to identify the critical issues.Based on these critical issues, precise procedures were developed for different aspects of urban construction. ICT technologies, assembly techniques and organizational patterns are proposed to enhance and optimize the processes existing within a construction site. Concepts such as logistics optimization, storage space rationalization or technological worker safety enhancement were thoroughly studied and ideas for improvement have been proposed as a result of the analysis.The procedures have been developed to integrate all the different activities during the building process, while seeking to avoid unwanted interferences between them. Through the application of the PANTURA procedures, construction sites can be turned into high-tech areas, where processes are streamlined, safety is paramount, nuisances are minimized, and latest advances in ICT technologies are used to facilitate coordination and management. This in turn will allow achieving a high degree of effectiveness during the construction process and as a logical consequence lead to the success of the projects.
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| 2. |
- Rempling, Rasmus, 1976, et al.
(författare)
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The need for research and innovation to facilitate upscaling of low-carbon concrete
- 2023
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Ingår i: IABSE Congress New Delhi 2023 Engineering for Sustainable Development. - : International Association for Bridge and Structural Engineering (IABSE). - 9781713883128 ; , s. 1199-1206
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Konferensbidrag (refereegranskat)abstract
- For decades, research has been carried out with a focus on concrete structures during curing to mitigate the risk of thermal cracking. Computer programs and aids/tools have also been developed to assess stress and cracking risk analysis of concrete structures during curing. However, today with the recent introduction of low-carbon concretes to reduce the environmental impact of constructions, the reliability of the tools and working procedures, i.e. concrete characterization, is questioned, and a roadmap for research and innovation is called for. The project's primary purpose is to investigate the need for research and innovation regarding upscaling the usage of low-carbon concrete. The nature of the study is based on an industry-focused workshop with specialists from Scandinavia. Increased knowledge of hardening concrete's cracking risk-related properties is of the utmost importance for the construction industry as the need for its understanding has recently increased.
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| 3. |
- 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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| 4. |
- Carneiro, Erica, et al.
(författare)
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Potential improvements in the life-cycle performance of support structures for onshore wind turbines – an interview study in Sweden
- 2022
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Ingår i: Proceedings of XXIV Nordic Concrete Research Symposium.
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Konferensbidrag (refereegranskat)abstract
- Wind energy is one of the fastest growing renewable energy sources thanks to its cost-effectivity and sustainability. This paper investigates how construction and maintenance of support structures for onshore wind turbines can be improved. Interviews were performed to identify potential areas for improvement in design, construction, operation, maintenance, and end-of-life. Defects due to poor detailing in design and construction have been recurring and may have important consequences. More structured data collection during the construction stages and more robust inspection protocols can help to ensure adequate life-cycle performance of the support structures. Possibilities to reuse and recycle foundations by the end of the turbine’s operational lifetime, which remain unexploited and unresearched, are also discussed.
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| 5. |
- Ek, Kristine, 1975, et al.
(författare)
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A harmonized method for automatable life cycle sustainability performance assessment and comparison of civil engineering works design concepts
- 2020
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Ingår i: IOP Conference Series: Earth and Environmental Science. - : IOP Publishing. - 1755-1307 .- 1755-1315. ; 588:5
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Konferensbidrag (refereegranskat)abstract
- The life cycle sustainability performance of civil engineering works is increasingly important. The possibility to influence the sustainability of a project design is larger in the conceptual stage than in later stages. Better-informed decisions regarding design choices’ impact on sustainability can be made by comparing conceptual project designs based on an assessment of their life cycle sustainability performance. It is essential that concepts are assessed in a harmonized way and compared impartially. Current standards provide the general framework for the assessment of sustainability performance, but do not give detailed guidance on calculation of sustainability indicators and their aggregation. Since design in automated systems is becoming increasingly common, there is a growing need for machine-readable data and automatable assessment methods. Assessment methods which can be applied using open-access data is important to achieve fair competition. This paper aims to provide a method for life cycle sustainability performance assessment and comparison of civil engineering works design concepts, possible to apply using open-access Environmental Product Declarations (EPDs) and life cycle assessment (LCA) data. The purpose is to enable fair and automatable sustainability assessments of design concepts, to facilitate impartial comparisons of such assessments as a basis for choosing sustainable designs. A literature review of relevant standards and scientific papers on sustainability assessment of construction and civil engineering works was performed. A harmonized, fair and automatable method for life cycle sustainability assessment and comparison of civil engineering works design concepts, well-suited for optimization purposes, is presented. However, the aim currently limits categories and indicators possible to include. The proposed method includes guidance on the calculation of environmental, social and economic indicators, based on LCA, life cycle costing (LCC) and external costs, and aggregation using normalisation and weighting factors of the Product Environmental Footprint (PEF). The proposed method allows for an impartial comparison of the sustainability of design concepts, resulting in better-informed decisions.
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| 6. |
- Ek, Kristine, 1975, et al.
(författare)
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Life Cycle Sustainability Performance Assessment Method for Comparison of Civil Engineering Works Design Concepts: Case Study of a Bridge
- 2020
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Ingår i: International Journal of Environmental Research and Public Health. - : MDPI AG. - 1661-7827 .- 1660-4601. ; 17:21, s. 1-34
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Tidskriftsartikel (refereegranskat)abstract
- Standardized and transparent life cycle sustainability performance assessment methods are essential for improving the sustainability of civil engineering works. The purpose of this paper is to demonstrate the potential of using a life cycle sustainability assessment method in a road bridge case study. The method is in line with requirements of relevant standards, uses life cycle assessment, life cycle costs and incomes, and environmental externalities, and applies normalization and weighting of indicators. The case study involves a short-span bridge in a design-build infrastructure project, which was selected for its generality. Two bridge design concepts are assessed and compared: a concrete slab frame bridge and a soil-steel composite bridge. Data available in the contractor’s tender phase are used. The two primary aims of this study are (1) to analyse the practical application potential of the method in carrying out transparent sustainability assessments of design concepts in the early planning and design stages, and (2) to examine the results obtained in the case study to identify indicators in different life cycle stages and elements of the civil engineering works project with the largest impacts on sustainability. The results show that the method facilitates comparisons of the life cycle sustainability performance of design concepts at the indicator and construction element levels, enabling better-informed and more impartial design decisions to be made.
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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. |
- Haghani Dogaheh, Reza, 1979, et al.
(författare)
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Toolbox for flexible refurbishment of existing bridges
- 2013
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- A large number of European bridges are in need for maintenance and upgrading. The upgrading activities for bridges usually involve strengthening and repair. Maintenance and upgrading of bridge structures is usually associated with traffic restrictions in form of complete or partial traffic disruptions. Traffic disruption, especially in in urban areas is one of the most challenging issues that road authorities have to deal with. In densely populated areas, the indirect cost of upgrading, i.e. strengthening and repair, could easily over take the direct cost of the project. Traditional materials and techniques are usually not efficient and often time consuming. Results of inquiries from road authorities in Pantura project revealed that (1) minimizing traffic disruption, (2) minimizing application time, (3) minimizing initial costs, (4) better long-term performance and lower maintenance costs are the priorities when it comes to strengthening and repair methods for bridge structures. Increase in the number of deficient bridges, in one hand, and limited financial resources in the other hand, call for more efficient materials and techniques, therefore, there is a large demand for developing new materials and techniques which are better and more efficient compared to traditional materials and methods. The current document presents deliverable D5.20 in WP5 which addresses task 5.2. This task aims at Developing new and improving existing strengthening and repair techniques so that they lead to; (1) shortening the application time and therefore less traffic disruption, (2) better material usage and higher efficiency and (3) application of new construction materials which have better durability properties and thus reduced LCC. The focus of the work in D5.20 has been on both developing innovative solutions and implementing innovation to solve problems and/or overcome existing shortcomings associated with existing solutions. The core of the work in this deliverable is to use fiber reinforced polymer, FRP, materials in upgrading of bridge structures due to advantages that they offer compared to traditional strengthening and repair materials and techniques (D5.8). The FRP bonding technique has been around since 1970th and attracted a lot of attention as an effective and economic solution for strengthening and repair of structural elements. Numerous bridges have been upgraded using this technique around the world, providing evidence for effectiveness and viability of this method. However, using FRPs is associated with some shortcomings and there is still a need for research and improvements. Issues such as high initial cost of the material, lack of design codes, quality control during application are among the hinders. In this regard, several shortcomings have been identified in WP5 and attempt has been made to solve them. Solving these problems would certainly lead to a greater acceptance of this technique among the authorities and bridge owners. The results of the research in task 5.2 have been presented as a collection including a new design model for adhesive joints in flexural steel members, application of an innovative FRP T-profile for strengthening of concrete members, a new method for using pre-stressed FRP laminates for strengthening and repair of concrete structures, recommendations on using geometrical modifications in adhesive joints and a method for fast curing of adhesive joints in order to reduce the strengthening and repair operation time. Experimental verifications and field applications have been carried out to prove the applicability of the proposed techniques.
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| 9. |
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| 10. |
- Mathern, Alexandre, 1986, et al.
(författare)
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A practical finite element modeling strategy to capture cracking and crushing behavior of reinforced concrete structures
- 2021
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Ingår i: Materials. - : MDPI AG. - 1996-1944. ; 14:3, s. 1-26
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Tidskriftsartikel (refereegranskat)abstract
- Nonlinear finite element (FE) analysis of reinforced concrete (RC) structures is characterized by numerous modeling options and input parameters. To accurately model the nonlinear RC behavior involving concrete cracking in tension and crushing in compression, practitioners make different choices regarding the critical modeling issues, e.g., defining the concrete constitutive relations, assigning the bond between the concrete and the steel reinforcement, and solving problems related to convergence difficulties and mesh sensitivities. Thus, it is imperative to review the common modeling choices critically and develop a robust modeling strategy with consistency, reliability, and comparability. This paper proposes a modeling strategy and practical recommendations for the nonlinear FE analysis of RC structures based on parametric studies of critical modeling choices. The proposed modeling strategy aims at providing reliable predictions of flexural responses of RC members with a focus on concrete cracking behavior and crushing failure, which serve as the foundation for more complex modeling cases, e.g., RC beams bonded with fiber reinforced polymer (FRP) laminates. Additionally, herein, the implementation procedure for the proposed modeling strategy is comprehensively described with a focus on the critical modeling issues for RC structures. The proposed strategy is demonstrated through FE analyses of RC beams tested in four-point bending—one RC beam as reference and one beam externally bonded with a carbon-FRP (CFRP) laminate in its soffit. The simulated results agree well with experimental measurements regarding load-deformation relationship, cracking, flexural failure due to concrete crushing, and CFRP debonding initiated by intermediate cracks. The modeling strategy and recommendations presented herein are applicable to the nonlinear FE analysis of RC structures in general.
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