| 1. |
- Saback, Vanessa, et al.
(författare)
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Crack monitoring by fibre optics and image correlation: a pilot study
- 2022
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Ingår i: IABSE Symposium Prague, 2022: Challenges for Existing and Oncoming Structures, Report. - : International Association for Bridge and Structural Engineering. ; , s. 437-444
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Konferensbidrag (refereegranskat)abstract
- As reinforced concrete structures reach the end of their design lives, technology for improving accuracy and efficiency of inspections and structural health monitoring rapidly progresses. Concrete cracking and reinforcement strains are two relevant parameters in assessing damage and safety ofthese structures. The use of Digital Image Correlation (DIC) systems and distributed Fibre Optic Sensors (FOS) to evaluate these parameters are two of the technologies that have been gaining momentum due to their advantages over other approaches. This study presents an experimental investigation of crack propagation of a reinforced concrete beam specimen through FOS and DIC.The FOS were positioned inside a groove carved in the rebar and in the concrete immediately outside the bar for comparison. The results showed a significant difference between both positions, with more reliable data coming from inside the bar. The addition of the DIC crack propagation images to the FOS analysis complemented the results, and good visual correlation was identified between both methods. This study is part of a broader research program, which aims at applying DIC and FOS for structural health monitoring of a real scale bridge structure.
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| 2. |
- Popescu, Cosmin, 1987-, et al.
(författare)
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Remote bridge inspection using optical methods
- 2022
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Ingår i: 24th NCR Symposium Proceedings. - : Nordic Concrete Federation.
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Konferensbidrag (refereegranskat)abstract
- Routine bridge inspections usually consist of visual observations. These inspections are timeconsuming and subjective. There is a need to identify new inspection techniques for infrastructure that reduce traffic disturbance, and improve the efficiency and reliability of the acquired data. This study compared the performance of three different imaging technologies for the threedimensional (3D) geometric modelling of existing structures: terrestrial laser scanning, closerange photogrammetry, and infrared scanning. Each technology was used to assess six existing concrete railway bridges. The results suggest that all methods investigated can be used to create 3D models, however, with different level of completeness.
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| 3. |
- Saback de Freitas Bello, Vanessa, et al.
(författare)
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Asset Management of Existing Concrete Bridges Using Digital Twins and BIM: a State-of-the-Art Literature Review
- 2022
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Ingår i: Nordic Concrete Research. - : Walter de Gruyter. - 0800-6377 .- 2545-2819. ; 66:1, s. 91-111
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Forskningsöversikt (refereegranskat)abstract
- The need to optimize investments in bridge maintenance has created a demand for improved bridge management systems (BMS). Outdated practices in bridge inspection and constant advances in information technology have also contributed to this demand. The use of Digital Twins (DT), although well established in other industries, is still incipient for asset management and structural analysis of bridges. There is a great deal of research on Building Information Modelling (BIM) for bridge inspection, but its post-construction potential is still under-explored. This study presents a state-of-the-art review of the literature on asset management for bridges using digital models such as BIM and digital twins. The review was conducting using a systematic approach. Despite the rapid increase in research on DT and the amount of existing research on BIM, several gaps remain to be addressed, such as the lack of consensus about the definition of digital twins, which has led to wrongful categorisation of digital models as DT. The complex data flow and software compatibility required to develop a functional DT have hindered the exploitation of their full potential so far. The integration of BIM post-construction to BMS and existing automation technologies can also significantly improve current practices of bridge management.
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| 4. |
- Saback de Freitas Bello, Vanessa, et al.
(författare)
-
Framework for Bridge Management Systems (BMS) Using Digital Twins
- 2022
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Ingår i: Proceedings of the 1st Conference of the European Association on Quality Control of Bridges and Structures. - Cham : Springer. ; , s. 687-694
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Konferensbidrag (refereegranskat)abstract
- Bridge structures have significantly long life spans; many medieval and historic bridges remain in operation in the world. The concept of bridge management contains the activities related to managing bridge inspections and condition assessment, which can be gathered into a Bridge Management System (BMS). Deterioration and failures have increased over the years in the already aging bridges; therefore, the importance of BMS to ensure safety of bridge operation and maximize investments in bridge maintenance has also increased. Digital Twin (DT) technology can be applied in the construction industry to achieve smart management through the entire life cycle of structures. Unlike the aerospace and manufacturing industries, the maturity of development of DT models in the construction industry still lags behind. In this study, a literature review was initially performed to gather knowledge on the origins of the digital twin concept and current best practice focused on bridge structures. A systematic approach for the literature review is presented in the methodology. Lastly, a framework for facility management of bridge structures using digital twins is proposed.
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| 5. |
- Täljsten, Björn, 1961-, et al.
(författare)
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Corrosion-free concrete structures by the use of FRP (Fibre Reinforced Polymers)
- 2022
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Ingår i: 24th NCR Symposium Proceedings. - : Nordic Concrete Federation.
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Konferensbidrag (refereegranskat)abstract
- Fibre reinforced polymers may be suggested as a solution to one of the major durability problems with reinforced concrete; the corrosion of the internal steel reinforcement. The durability of fibre reinforced polymers, FRP, e.g. towards chlorides, has the potential of saving extensive maintenance costs and avoiding resulting inconveniences for the public. This paper presents a pilot study with the use of glass fibre reinforced polymers, GFRP, as internal reinforcement for concrete structures. In the comparison between major international design guidelines, similar design procedures for ultimate limit state, ULS, but different design procedures for serviceability limit state, SLS, are used. Four T-beams, of which two were reinforced with GFRP rebars and the other two with steel rebars, were tested to failure in 4-point bending. Optical strain measuring equipment was used for the measurement of crack propagation. A comparison between predictions of failure loads, deflections and crack widths based on the design guidelines and the experimental results has been performed. For both GFRP reinforced beams different from predicted failure modes occurred, but at loads almost at the predicted level or higher. Extensive deflections and crack propagation gave clear warnings before failure. The behavior of the GFRP reinforced beams in SLS was reliable predicted by the design guidelines for FRP with the same accuracy as for the reinforced concrete beams. The SLS predictions of crack widths and deflections showed increasing overestimation for increasing reinforcement ratios. SLS criteria have shown to be governing in the design for the GFRP reinforced members.
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| 6. |
- Täljsten, Björn, 1961-, et al.
(författare)
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Wireless monitoring for assessment of concrete railway bridges – Experiences from field tests
- 2022
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Ingår i: 24th NCR Symposium Proceedings. - : Nordic Concrete Federation.
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Konferensbidrag (refereegranskat)abstract
- This paper focus on assessment on a prestressed three span concrete box bridge by the use of a wireless monitoring system in combination with visual inspection. The bridge is located in the very north of Sweden, in Abisko. A visual inspection of the bridge carried out the 18th of August in 2016 several crack patterns were mapped on the inside of the box girder bridge located near supports in the spans on both sides of the bridge. The cause of the cracks are not completely clear. To reveal the reason for cracking a long term project has been initiated by Trafikverket. Here a new developed wireless system has been used. Investigating change in crack widths by the use of LVDTs and strain gauges. Also accelerations are monitored together with the temperatures. In addition also fibre optic systems and non-destructive tests were carried out (not reported here). The results/conclusions presented in the paper are preliminary and final results will be presented 2021.
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