| 11. |
- Mathern, Alexandre, 1986, et al.
(author)
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Experimental study of time-dependent properties of a low-pH concrete for deposition tunnels
- 2018
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In: fib Symposium. - 2617-4820. ; , s. 1726-1735
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Conference paper (peer-reviewed)abstract
- The Swedish Nuclear Fuel and Waste Management Company developed a method for the final disposal of canisters for spent nuclear fuel in tunnels at depths of about 500 meters. The concept for closure of the deposition tunnels is based on a bentonite seal supported by a spherical concrete dome structure. In order to fulfil the requirements specific to the repository concept, a special mix of low-pH self-compacting concrete was developed. A series of large-scale castings and laboratory tests were conducted to gain experience on this low-pH concrete mix, in conjunction with the full-scale demonstration test of an unreinforced concrete dome plug in the underground hard rock laboratory in Äspö, Sweden. The laboratory tests aimed at studying the creep properties under high sustained compressive stresses of the low-pH concrete mix, its shrinkage properties and the properties of the rock-concrete interface. This paper provides an overview of these tests and analyses the latest results of the recently completed creep tests, which include 6 years of measurements. These results allow to improve understanding of the structural behaviour of the concrete plug and to assess the effects of the very high pressure acting on the plug on its deformations, cracking and water tightness.
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| 12. |
- Rempling, Rasmus, 1976, et al.
(author)
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Research Roadmap - Information Integration in Construction
- 2019
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Reports (other academic/artistic)abstract
- This Roadmap is developed for a challenging Global environment where fundamental paradigms such as data generation and analysis, are shifting at a seismic rate, while change in Construction Industries across the Globe is, in the main, confined to large-scale projects and slow. Against this background, the authors set out to also give a ‘voice’ to small-to-medium scale projects through which the construction output Worldwide is delivered. Hence, project scale was one of the key considerations throughout this Roadmap. Moreover, the authors conceptualized data integration by taking the realities of doing business’ in construction into consideration. The emergent framework facilitates the discussion of knowledge and data integration at organisational, team, operational and technical levels across key project phases. This approach recognizes that business is done through projects but change can only come about if appropriate organizational structures and processes are put in place. Last, but not least, the authors strived to ensure that data integration was not considered solely from a technical perspective. Organisational, team and individual aspects of data integration were integrated in the research framework. Through our work the individual’s willingness to collaborate emerged as a critical driver for high levels of integration, while our survey did identify “Reluctance to work across professional boundaries” as a major barrier to integration. Hence, we conclude that research on integration should pay due attention to the individual.
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| 13. |
- Aygül, Mustafa, 1970, et al.
(author)
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A comparative study of different fatigue failure assessments of welded bridge details
- 2013
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In: International Journal of Fatigue. - : Elsevier BV. - 0142-1123. ; 49:0, s. 62-72
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Journal article (peer-reviewed)abstract
- Five different welded joints frequently used in steel bridges have been selected to investigate the accuracy and applicability of three fatigue assessment methods. The first method, also categorised as the global method, is the nominal stress method, while the more advanced methods are the hot spot and the effective notch stress methods. Solid element based finite element models for welded bridge details were created by following the modelling requirements of each fatigue assessment method. A statistical evaluation based on the results of the finite element analyses and the fatigue test data collected from the literature was performed to determine the mean and characteristic fatigue strength. In addition, the standard deviation for each data series was also determined to conclude how well each method describes the fatigue strength of each welded detail. A method with a lower standard deviation is regarded as more accurate. Moreover, the evaluated results from each method were compared with the recommended fatigue strength values in the Eurocode 3 (EN 1993-1-9:2005) and IIW codes. In the light of the test results in this study, it appears that the codes are in reasonable agreement with the test data, even though a few examples of the opposite occurred. The conclusion based on the revised results in this article indicates that the nominal stress method yields satisfactory results, despite its simplicity. When considering the effort involved in creating FE models for numerical analysis, it seems clear that the choice of the nominal method is fairly acceptable.
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| 14. |
- Blomfors, Martin, et al.
(author)
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Reliability analysis of corroded reinforced concrete beam with regards to anchorage failure
- 2019
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In: Life-Cycle Analysis and Assessment in Civil Engineering. - : CRC Press/Balkema. - 9781138626331 - 9781351857574 ; , s. 337-344, s. 337-344
-
Conference paper (peer-reviewed)abstract
- Reinforcement corrosion is a common problem in reinforced concrete infrastructure today, and it is expected to increase in the future. To simply replace the corroded structures with new ones requires large resources, both in financial and environmental terms. Therefore it is important that existing structures are used to their full potential, also after the onset of corrosion. This paper presents a reliability study of the anchorage capacity of a reinforced concrete beam including reinforcement corrosion. The sensitivity of the different input parameters is also studied. As expected, the results show that the reliability is reduced with corrosion; the magnitude depends to a large extent on the modelling uncertainty used for the bond model for corroded reinforcement. The sensitivity analysis shows an influence of corrosion also on the sensitivities of the input parameters, which is expected based on the properties of the underlying bond model. This paper demonstrates that probabilistic evaluations give valuable insight of the reliability, which can be used to prolong the service-life of existing infrastructure and save both money and the environment.
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| 15. |
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| 16. |
- Bannova, Olga, 1964
(author)
-
Architectural approach to planning in the extreme arctic environment.
- 2016
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In: archiDOCT: Transformable Architecture. - 2309-0103. ; 4:1, s. 53-67
-
Journal article (peer-reviewed)abstract
- Extreme environments in Polar Regions share similar facilities and operations, design and planning challenges: extreme cold temperatures, structural problems, high standards for materials, resources limitations (including people), transportation and logistics. Nevertheless, they differ depending on local cultural and social traditions and climate challenges specific to a particular region. Environmental hardships create challenges that reflect on sets of architectural requirements. The paper discusses these challenges and their influences on form developing factors, site orientation and circulation, - factors that affect budget considerations as well. The paper also discusses criticality of addressing such impacts at the programming design stage especially in challenging environments, in order to avoid costly adjustments at later development stages.The paper argues that integrating an architectural approach into planning of construction and related to it activities in Polar Regions is critical for enabling sustainability and resilient strategies there. The importance of such integration comes from the fact that engineering-oriented developers follow strictly industry-specific technical regulations and standards. Simultaneously, planning construction work and design in extreme conditions becomes a more complex process that calls for a new methodology, which would differ from common regulatory “checklists” that most companies implement in their practices there.This paper outlines and categorizes recurrent and specific to extreme environment and conditions events based on select research methods that include verbal data collection and case studies analysis. Figures Of Merit method employed for identification of important lessons that can be applied across different settings; and the ‘HSB Sustainable Living Lab’ project is suggested for effectiveness and verification purposes.Understanding of relationships and influences between different facets of human society and architecture can help to find a design approach and optimize needs and requirements for various types of people living and working in extreme environments of Polar Regions, their societies and cultures.
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| 17. |
- Ek, Kristine, 1975, et al.
(author)
-
Multi-criteria decision analysis methods to support sustainable infrastructure construction
- 2019
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In: IABSE Symposium, Guimaraes 2019: Towards a Resilient Built Environment Risk and Asset Management - Report. ; , s. 1084-1091
-
Conference paper (peer-reviewed)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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| 18. |
- Mathern, Alexandre, 1986, et al.
(author)
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Sustainability-driven structural design using artificial intelligence
- 2019
-
In: 20th Congress of IABSE, New York City 2019: The Evolving Metropolis - Report. ; , s. 1058-1065
-
Conference paper (peer-reviewed)abstract
- The construction industry is responsible for a large share of the global environmental impact. The need for addressing sustainability and increased competition calls for the development of innovative design methods that include sustainability in a transparent way. The aim of this work is to propose a framework to use machine learning and artificial intelligence (AI) for structural design optimization based on sustainability and buildability criteria. AI opens up new possibilities to optimize and assess structures early in the planning and design stages. In that way, it is possible to decrease the negative and enhance the positive environmental, economic and social impacts and create a more time‐ and cost‐effective design process. The work is meant to serve as a first step toward the development of AI‐based methods in the construction industry, which can bring digitalization in the construction industry to a new level and create new services and business models.
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| 19. |
- Rempling, Rasmus, 1976, et al.
(author)
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Aspects of Integrated Design of Structures: Parametric Models, Creative Space and Linked Knowledge
- 2015
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In: Civil Engineering and Architecture. - 2332-1121. ; 3, s. 143-152
-
Journal article (peer-reviewed)abstract
- In the construction industry, collaborative working methods with overlapping domains have been developing side by side with information and communication technology. Recently, efforts have been made to combine these methods in order to facilitate the integration of disciplines. Research on collaborative work has resulted in the promising "integrated project delivery" methodology, whereas research on information and communication technology has resulted in building information modelling. In this paper, we propose three principles for integrated design: "parametric models", "creative space" and "linked knowledge". These principles have been derived during the course of the TailorCrete Project. The project involves contributions from architects, structural engineers, contractors and building material manufacturers, as well as scientists of the built environment. All principles are elaborated upon with regard to their connection to integrated design and how they are carried out in practice; the elaboration is based on results collected from the TailorCrete project and from research results found in the literature. This paper concludes that parametric models, creative space and linked knowledge are the three main aspects that should be pursued in order to achieve and implement a practical integrated design process
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| 20. |
- Rempling, Rasmus, 1976, et al.
(author)
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Automatic structural design by a set-based parametric design method
- 2019
-
In: Automation in Construction. - : Elsevier BV. - 0926-5805. ; 108:December
-
Journal article (peer-reviewed)abstract
- Modern structural design faces new challenges, such as addressing the needs of several stakeholders and satisfying the criteria for achieving sustainability. The traditional design process does not allow resolution of these challenges. The purpose of this project was to investigate the applicability of a Set-Based Parametric Design method to the structural design process of bridges. The focus was on the early design stage, in which the design team evaluates design alternatives against a chosen set of criteria. The main challenge in this stage of design is that the process should be cost- and time-effective while allowing comparison of the different alternatives and their evaluation in terms of the different design criteria. Certainly, structural design is often performed by a discussion between the different stakeholders involved in this process, i.e. the client, contractor, and engineering team. An evaluation of alternatives against criteria requires a more detailed design, which is contradictory to the early design stage when information is scarce. The selected approach was to develop a script that can generate information for decision-making, automate the structural design process, perform common routine design tasks, and control the numerical analysis. The method combined Set-Based Design, Parametric Design, Finite Element Analysis and Multi-Criteria Decision Analysis. Three existing bridges were selected to demonstrate the applicability of the developed method. The method was successfully applied and it was observed that it resulted in bridges that were more efficient in terms of material costs and carbon dioxide equivalent emissions compared with existing bridges. By delaying the decisions and developing the sets of alternatives, various alternatives can be assessed and evaluated, in the design stage, against different sustainability criteria.
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