| 1. |
- Ekström, Daniel P T, 1976, et al.
(författare)
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Climate impact optimization in concrete bridge construction
- 2017
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Ingår i: IABSE Conference, Vancouver 2017. - : International Association for Bridge and Structural Engineering (IABSE). - 9783857481536 ; , s. 1161-1168, s. 1161-1168
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Konferensbidrag (refereegranskat)abstract
- Estimates indicate that the total climate impact, from a lifecycle perspective, generated by Swedish construction processes reaches the same magnitude as emissions from all passenger cars in Sweden. A large part of the emissions from construction of roads and railways arise from production of steel and concrete used in bridges and other infrastructure structures. In this research, several cases of existing concrete bridges have been investigated. The case studies are in a very firm way analyzed, and then opportunities for reducing climate gas emissions are described and elaborated upon. Accordingly, design and dimensioning through the use of today's technology and material selection are discussed. Without developing new ways to construct bridges, or comparing concrete with other materials, a useful guide on how to use technology and opportunities that are available for constructing climate smarter versions of standard bridges today is developed and described.
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| 2. |
- Ekström, Daniel P T, 1976, et al.
(författare)
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Industrial bridge building- An effective bridge construction process through an integrated design and construction process
- 2014
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Ingår i: Nordic Concrete Research. - 0800-6377. - 9788282080439 ; 2014:2, s. 79-82
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Konferensbidrag (refereegranskat)abstract
- This PhD-project aims to develop and industrialise bridge building, in order to achieve a more efficient and sustainable bridge construction process. The advancements of several key areas - materials science and technology, design and analysis methods, production techniques and information and communication technology - have resulted in a vast potential to rationalise the process and renew the designer's role. Initially, the project will define effective bridge construction criteria’s by means of interviews and case-studies. The work should result in an integrated design and production process. This project is a collaborative project, involving: Swedish Transport Administration, WSP and Chalmers.
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| 3. |
- Ekström, Daniel P T, 1976, et al.
(författare)
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Industrial bridge construction: Need for a more effective bridge construction process
- 2015
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Ingår i: The Eighth International Structural Engineering and Construction Conference, Sydney, Australia, November 23-28, 2015. - : ISEC Press. - 9780996043717 ; , s. 1115-1120
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Konferensbidrag (refereegranskat)abstract
- Designing for ease of construction is something that is always demanded by contractors and a challenge for the designers. It is widely known that the ability to influence a structure and its future properties is at its greatest in early stages, i.e. the project preparation phase followed by the design phase. Despite the fact that there is an obvious need for knowledge of construction in design work, there is a lack of a consistent and structured transmission of experience between the construction stage and the designing engineers. The results in this project are achieved based upon three standalone studies. A thorough literature review, a meta-analysis of the current research covering effective bridge construction and a study of the current industrial view on how the industry intend to achieve a more effective bridge building process. Based upon these studies it is clear that using a holistic approach and a production oriented design methodology is likely to generate the progress that the construction industry needs.
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| 4. |
- Ekström, Daniel P T, 1976, et al.
(författare)
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Integrated project team performance in early design stages – performance indicators influencing effectiveness in bridge design
- 2019
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Ingår i: Architectural Engineering and Design Management. - : Informa UK Limited. - 1745-2007 .- 1752-7589. ; 15:4, s. 249-266
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Tidskriftsartikel (refereegranskat)abstract
- To create multi-functional and integrated project teams, and to adopt a team perspective in the early design stages, it is recognised in the literature that a more effective process is required; one that reduces the probability of costly changes and difficulties during construction. This paper presents an evaluation of project team collaboration during early design and development of construction documents for bridges in Sweden. The purpose was to study key variables influencing the performance of integrated project teams by using importance performance analysis (IPA). A self-evaluation questionnaire addressed clients, contractors, and structural engineering consultants in the Swedish bridge construction industry. The questionnaire addressed three essential cornerstones of value-creation during the engineering design process; culture, structure and competence. These were addressed at three organisational hierarchy levels, the organisation, project, and the individual level. Our results show that increased support and resources are required at the project level for better project team performance. Results further identify that project culture needs to be developed including both collaboration and social relationships as well as project competence, especially the ability to solve mutual issues. This research offers a ‘generalised’ and prioritised view of the challenges in the Swedish bridge construction industry in terms of creating integrated project teams.
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| 5. |
- Ekström, Daniel P T, 1976, et al.
(författare)
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Integrated project teams in early design stages - Key variables influencing cost effectiveness in bridge building
- 2016
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Ingår i: 19th IABSE Congress Stockholm, 21-23 September 2016, Challenges in Design and Construction of an Innovative and Sustainable Built Environment. ; , s. 598-606
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Konferensbidrag (refereegranskat)abstract
- The construction industry is usually regarded as a complex, multidisciplinary and project focused environment. It is also regularly identified as a one-of-a-kind nature, hence focus is on the uniqueness of projects rather than in similarities. The results presented in this article are based on questionnaire addressed to clients, contractors, and designers, mainly active within the Swedish infrastructure sector. The purpose is to highlight key-variables influencing cost effectiveness for the organization of integrated project teams, designing of projects, and construction at site. The results indicate that more attention needs to be paid to the actual project setting if to fully gain the benefits from integrated project teams. Further, the results indicates that it is mainly project culture; collaboration and social relationships, and project competence, the ability to solve mutual issues, that needs to be developed.
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| 6. |
- Ekström, Daniel P T, 1976, et al.
(författare)
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Predicting project performance using pre-construction performance indicators - A case study evaluation
- 2019
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Ingår i: 20th Congress of IABSE, New York City 2019: The Evolving Metropolis - Report. - 9783857481659 ; , s. 1438-1443
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Konferensbidrag (refereegranskat)abstract
- Predicting the outcome of a construction project largely relies on estimated targets of time and cost. Still, hitting the targets does not mean that the project is a success on all performance levels. Here, a retrospective case study was undertaken on a construction project identified as a successful project by the partners involved. The purpose of the study was to validate conceptual design indicators of a high-performance construction project as reported in the literature, by answering the following research questions: "What characterizes the dialogue between the different disciplines; (2) What is the dialogue about; and (3) When in the process do questions arise?" Findings indicate that the interprofessional dialogue within the project team was well established. The paper introduces a discussion that the dialogue benefited from the collaborative project environment as well as the early design intent. Further, the study also suggests that the interprofessional dialogue supported a sound project team development.
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| 7. |
- Ekström, Daniel P T, 1976, et al.
(författare)
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Samarbetsprojekt för effektivare brobyggande
- 2014
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Ingår i: Bygg & Teknik. - 0281-658X. ; 2014:7, s. 58-61
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)abstract
- Den svenska anläggningsbranschen har i ett flertal utredningar fått skarp kritik på grund av dålig produktivitet. Forskning visar på samma tendenser i övriga Europa och USA. Vissa mätningar tyder på att byggandet i den svenska anläggningsbranschen har en kostnadsökning som är dubbelt så hög jämfört med övriga branscher under de senaste 20 åren. Låg produktivitet och låg innovationsförmåga i byggbranschen leder till högre kostnader som inte garanterat ger en högre kvalitet. Trenden behöver vändas så att avkastningen på investeringar i vår infrastruktur ökar! Det första steget är att integrera konstruktions- och produktionsprocesserna, vilket ger kortare ledtider för både planering och uppförande av byggnadsverk. Onödigt långa byggtider orsakar störningar för andra aktörer i samhället.I ett pågående doktorandprojekt, som är ett samarbete mellan Trafikverket, WSP och Chalmers, söks möjligheten till att öka produktiviteten inom den svenska anläggningsbranschen. Huvudspåret är att utveckla och industrialisera brobyggandet. En effektivare byggindustri skapar möjligheter till att generera ett mervärde för samhället där mervärdet exempelvis kan motsvaras av att konstruktioner byggs med högre kvalitet till samma kostnad som idag alternativt samma eller högre kvalitet till en lägre kostnad än idag. Bortsett från rena kostnader bör naturligtvis en effektivare byggindustri också se till att lösningar väljs utifrån ett hållbart samhälle men med bibehållen fokus på produktivitet och innovation. En sådan lösning kan variera från själva processen till konstruktionsdetaljer.
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| 8. |
- Ekström, Daniel P T, 1976, et al.
(författare)
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Structural performance assessment of post-tensioned concrete beams by embedded continuous fibre optics
- 2023
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Ingår i: IABSE Congress New Delhi 2023 Engineering for Sustainable Development. - 9781713883128 ; , s. 1216-1224
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Konferensbidrag (refereegranskat)abstract
- Prestressed concrete structures have numerous advantages over conventionally reinforced concrete, though the usage of post-tensioned structures has declined over the last two decades. By distributed optical fibre sensors, key performance indicators of the post-tensioned concrete specimens were monitored and evaluated. Initial losses and long-term effects affecting prestressing force, deflections and cracks were tracked and compared to theoretical calculation methods. It was found that the theoretical calculation methods mostly agreed well with results from the distributed optic fibre sensors. The loss of prestressing force due to mechanical creep and relaxation was overestimated in theoretical calculation methods by approximately 6 %, while the loss due to friction was overestimated by 0.6 %. Regarding deflections, the relative error ranged from 0 % to 3.3 % and 0 % to 2.9 % for the reference specimen and post-tensioned beam, respectively.
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| 9. |
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| 10. |
- af Hällström, Anna, 1987, et al.
(författare)
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The role of social ties in collaborative project networks: A tale of two construction cases
- 2021
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Ingår i: Construction Management and Economics. - : Informa UK Limited. - 1466-433X .- 0144-6193. ; 39:9, s. 723-738
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Tidskriftsartikel (refereegranskat)abstract
- Collaborative project delivery models (CPDMs) are increasing in popularity as infrastructure con-struction projects become more complex and grow in scale and scope. CPDMs build on highlevels of trust, information exchange and formal contractual relations, creating complex relation-ships between actors in the project network. The literature emphasizes the procurement phaseand contractual aspects of CPDMs; however, few studies explicitly focus on the role of socialrelationships in CPDM projects. Social network theory has recently been introduced in the archi-tecture, engineering and construction industry industry to study relationships between networkactors, but the role of social ties within CPDM project networks is still unclear. Through twoqualitative case studies, we have analyzed the role of social ties in projects applying a CPDMcontract. The empirical evidence of 41 semi-structured interviews and observations points toaspects that affect the development of social ties in CPDMs, such as initial project setup, projectidentification, perception of actors, resource sharing and shared space, as well as the importanceof formal and informal ties for supporting collaborative project practices. The evidence showshow social ties develop into negative or positive bonds affecting the level of collaboration. Thisstudy contributes by emphasizing the interplay between project networks using CPDMs andsocial ties.
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