| 1. |
- 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
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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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| 2. |
- Larsson Ivanov, Oskar, et al.
(author)
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Prolca—treatment of uncertainty in infrastructure LCA
- 2019
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In: Life-Cycle Analysis and Assessment in Civil Engineering. - : CRC Press/Balkema. - 9781138626331 - 9781351857574 ; , s. 2923-2930
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Conference paper (peer-reviewed)abstract
- The construction, operation and maintenance of transportation infrastructure require energy and materials which impact the environment. Large infrastructure projects thus use resources intensively and leave a significant environmental footprint. To demonstrate and support the sustainability of such large-scale projects, life cycle assessment (LCA) has become a common tool to evaluate environmental impacts in all stages of infrastructure life cycle, from raw material production through end-of-life management. However, the various phases of the assessment are all associated with uncertainties. If decisions are made without consideration of these uncertainties, they might be misleading and suboptimal. In this paper, results are presentedwhere variations associated with different parameters and tools for life cycle assessment have been considered using probabilistic methods. A categorization of common uncertainties in LCA is also included. The most influential parameters can be identified with sensitivity analysis methods, since for LCA with a large number of parameters it may be unreasonable to incorporate all in a probabilistic simulation. For a limited amount of influential variables, Monte Carlo simulation has been used to assess the effects of uncertainties on the results.A bridge has been used as a case study to find important aspects in infrastructure LCA. The results indicate that if the most influential parameters are considered as random variables, it is possible to estimate the uncertainty and increase the validity of the life cycle assessment.
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| 3. |
- Karlsson, Freddie, et al.
(author)
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Online tracking of inputs, states and parameters of structural dynamic systems
- 2019
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In: Life-Cycle Analysis and Assessment in Civil Engineering. - : CRC Press. - 9781138626331 ; , s. 211-217
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Conference paper (peer-reviewed)abstract
- This paper presents a novel filtering algorithm for joint input-state-parameter estimation. The algorithm is derived from an existing joint input-state estimation algorithm. In each step, the system model is linearized around the current state, yielding an algorithm which is similar to the Extended Kalman filter. It is shown that, in the application to linear structural dynamic systems, the analytical expressions for the Jacobian matrices involved in the linearization are readily available due to the choice of parametrization. The proposed methodology is verified by numerical simulations for a four story shear building.
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| 4. |
- Leander, John, 1976-, et al.
(author)
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The value of monitoring on the service life prediction of a critical steel bridge
- 2018
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In: Life Cycle Analysis and Assessment in Civil Engineering: Towards an Integrated Vision: Proceedings of the Sixth International Symposium on Life-Cycle Civil Engineering (IALCCE 2018), 28-31 October 2018, Ghent, Belgium. - 9781138626331 ; , s. 2121-2128
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Conference paper (peer-reviewed)abstract
- This paper is focused on the service life prediction of steel bridges subjected to a combination of corrosion and fatigue. Both deterioration mechanisms are dubious to handle in theoretical assessments due to large uncertainties, on the action effect side and the resistance side. A reliability-based assessment in combination with updating considering monitoring and inspections provide an approach to reduce the uncertainties. To evaluate what assessment actions to engage, this approach has been combined with Bayesian decision theory which provides a rational basis to evaluate the value of information (VoI). The Old Liding\"{o} Bridge in Sweden is used as a case study to demonstrate the reliability-based approach. This bridge is subjected to severe corrosion and has been deemed unfit for service. However, it provides the only link to the island Liding\"{o} for the local tram and pedestrians why the bridge owner has decided to keep it in service until a new bridge is in place. To secure the safety of the bridge, recurrent inspections are conducted and discovered defects are repaired immediately. A system for continuous monitoring of critical parts was installed during the spring 2017. The bridge, the approach for assessment, and the procedure for evaluating the VoI are presented in the paper.
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| 5. |
- Nasr, Amro, et al.
(author)
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Climate change impact on safety and performance of existing and future bridges
- 2018
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In: Proceedings of the Sixth International Symposium on Life-Cycle Civil Engineering (IALCCE 2018). ; , s. 1735-1741, s. 1735-1741
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Conference paper (peer-reviewed)abstract
- Recent decades have seen an increased attention towards the threat of climate change to our built environment and not least our infrastructure. Accounting for the different ways in which potential climate change scenarios can affect our infrastructure is paramount in determining appropriate adaptation and risk management strategies. This paper presents the initial findings of a new research project which is concerned with establishing an improved management of the risks to our infrastructure, especially bridges, in light of a changing climate. In this paper, a preliminary survey of the climate change related risks on bridges is conducted. Timely consideration of these impacts is of utmost importance to ensure a satisfactory performance of our bridges in the future. The interplay between the different risks and how the occurrence of one risk may influence other risks is also briefly discussed. The future stages of the project are mentioned as well. The authors would like to acknowledge the support of the Swedish Transport Administration. Any opinions, findings, or conclusions in this work are those of the authors and are not necessarily in accordance with those of the Swedish Transport Administration.
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