| 1. |
- Flansbjer, Mathias, et al.
(författare)
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Mechanical behaviour of concrete piles affected by sulphate attack
- 2013
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Ingår i: Proceeding of the International IABSE Conference. - 9783857481239 ; , s. 389-392, s. 556-557
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Konferensbidrag (refereegranskat)abstract
- Assessing the remaining service life is vital for the planning of maintenance of concrete constructions in aggressive environments. Here we present results from testing of two concrete piles affected by sulphate attack in marine environment. A multi-method approach going from micro scale to structural level has been applied. The crack propagation was monitored during loading by means of DIC and AE. After the test crack patterns was studied using fluorescence microscopy. Furthermore, non-linear finite element analysis at the structural level was used to study the influence of the chemical attack on the response of concrete piles.
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| 2. |
- Gonzalez, Ignacio
(författare)
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Temperature dependence of ballast stiffness on a railway bridge
- 2013
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Ingår i: Assessment, Upgrading and Refurbishment of Infrastructures. - : International Association for Bridge and Structural Engineering (IABSE). - 9783857481239
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Konferensbidrag (refereegranskat)abstract
- In this study it is demonstrated that ballasted bridges can exhibit a step-like variation on the eigenfrequencies as the temperature varies. This change manifests as an important increase in the eigenfrequencies as temperature drop below 0 °C. The reason for this phenomenon is unknown but it is theorized that it is due to frozen water acting as a bonding agent between the ballast particles, increasing the stiffness of the ballast layer and thus the eigenfrequencies of the bridge. The step-like nature of the change and the fact that it occurs at around 0 °C seem to point in this direction. A Finite Element model of the bridge was developed to explore what elasticity modulus for the ballast would lead to an increment of the eigenfrequencies that matches the observed one.
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| 3. |
- Nilimaa, Jonny, et al.
(författare)
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Extended Life of Railway Bridges. Results from EC-FP7-project MAINLINE
- 2013
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Ingår i: Assessment, Upgrading and Refurbishment of Infrastructures. - Zürich : International Association for Bridge and Structural Engineering. - 9783857481239 ; , s. 314-315
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Konferensbidrag (refereegranskat)abstract
- There is a need to extend the life of many existing railway bridges. To facilitate this is one of the objects of the EC-FP7-Project MAINLINE, covering a period from 2011 to 2014. Three case studies are presented in which existing bridges are being studied in order to extend their life length: First a concrete trough bridge strengthened with post stressed bars in drilled holes through the slab is considered; followed by another concrete trough bridge strengthened with sawn in Near Surface Mounted Reinforcement (NSMR) of Carbon Fibre Reinforce Polymers (CFRP); and finally a steel truss bridge which will be loaded to failure to calibrate the assessment methods.
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| 4. |
- Tahershamsi, Mohammad, 1986, et al.
(författare)
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Assessment of anchorage capacity of naturally corroded reinforcement
- 2013
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Ingår i: Assessment, Upgrading and Refurbishment of Infrastructures. - : International Association for Bridge and Structural Engineering (IABSE). - 9783857481239
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Konferensbidrag (refereegranskat)abstract
- Corrosion of reinforcement is a significant cause of deterioration in existing structures. While this topic has been extensively studied using artificially corroded test specimens, little is known about the actual response of naturally corroded structures. Overall, the literature suggests that drastic reduction of the corrosion time, i.e. from years to days, in accelerated corrosion process, might markedly influence the bond and the anchorage capacity of a reinforced concrete member. Consequently, the anchorage capacity of specimens with naturally corroded reinforcement was investigated. Since a large scatter was observed in the tests of the first series, see [1, 2], fourteen more specimens were tested in a second round using samples from the other side of the same bridge. The specimens were carefully documented regarding crack patterns, crack widths, and spalled regions before testing. In all cases, diagonal shear cracks preceded a splitting-induced pullout failure; i.e. anchorage failure was achieved as expected. Subsequent work will combine results from both test series, such as load versus deflection, free end-slip and crack patterns; and compare these with the predictions from detailed nonlinear finite element modelling, using the available bond and corrosion models. These will result in a better understanding of the structural behaviour of corroded reinforced concrete structures to field conditions.
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