| EPSRC Reference: |
EP/J01642X/1 |
| Title: |
Concurrent Fatigue / Environmental Long-Term Effects on Joints in FRP Deck Road Bridges |
| Principal Investigator: |
Sebastian, Professor WM |
| Other Investigators: |
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| Researcher Co-Investigators: |
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| Project Partners: |
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| Department: |
Civil Engineering |
| Organisation: |
University of Bristol |
| Scheme: |
Overseas Travel Grants (OTGS) |
| Starts: |
01 January 2012 |
Ends: |
30 September 2012 |
Value (£): |
12,644
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| EPSRC Research Topic Classifications: |
| Civil Engineering Materials |
Structural Engineering |
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| EPSRC Industrial Sector Classifications: |
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Summary on Grant Application Form |
This research will entail experimental work in environmental chambers along with finite element analysis (FEA). All tests and analyses will be on specimens (supported by material tests) comprising GFRP deck units adhesively bonded to each other and to steel plates, with anti-skid surfacing applied to the units' top flanges because such surfacing can make a structural contribution and can crack at low temperatures to allow moisture ingress leading to joint degradation. The specimens will represent GFRP decking adhesively bonded to and spanning across steel I-beams in practice ; the steel plate of each specimen representing the top flange of an I-beam. Three joint types will exist in these specimens : bonded deck-steel joints ; bonded deck-deck joints ; surfacing-deck joints.
Specimens (and coupons) will be subjected to 3 exposure regimes, each including humidity control. In regime 1, salt solution will be sprayed onto the deck-steel joints (representing salt spray thrown up by lorry tyres from the road below a FRP deck bridge in winter), and salt solution will be applied to the surfacing. In the chamber, a winter low temperature will be applied concurrently with fatigue. In regime 2, water will be sprayed onto the bonded deck-steel joints (representing water spray from tyres on a rained-on road below a FRP deck bridge), and unsalted water applied to the surfacing. In the chamber, adverse temperatures re rain sitting on bridge decks will accompany fatigue. Regime 3 entails fatigue & high temperature (& of course humidity control). These regimes mimic very cold wet spells (R1), rainy spells with adverse temperatures (R2) & hot spells (R3). The number of fatigue cycles (totalling up to 10 million) to be applied for each regime will be based on approximate lorry numbers for these spells on representative bridges, supplied by the Highways Agency. Fatigue will entail cyclic concentrated patch loading (to simulate tyre loading) onto the surfacing.
Strain, moisture and temperature data will be intermittently recorded from the specimens during tests. The patch loads will generate prying in the deck-steel joints in addition to the other joint stresses associated with the local response of the deck to these loads. At intervals, the specimens will be transferred from the chambers to nearby test rigs for static load application to permit assessment - using the instrumentation data - of any changes to the mechanical characteristics of the joints.
The parallel FE studies will seek to predict joint behaviour which compares well with the test outputs, but by placing minimal computational demands in so doing. Hence features such as limits on refining of the mesh without compromising predictive capability will be of interest.
The specimens will be either formed to the best ability of the lab environment, or will contain deliberate defects at one of the three joint types. Between the specimens without deliberate defects, the fatigue and environmental actions will be introduced individually, then together, to enable build up of understanding of the response of the joints to these actions.
Conference and journal papers will be written during the visit on the observations on degradation mechanisms, the impact of degradation on joint structural integrity, and the ability of FEA to predict the changes in joint behaviour. The emerging ideas will also inform a proposal for European funding - to be written during the visit, with leadership from the PI - to build, instrument and monitor a bridge at a heavily trafficked location of severe environmental exposure. This will in part entail travelling to countries in Europe to get plans for the proposal off the ground with potential partners.
During the collaboration, emerging results will be written up for inclusion in a UK document due for release in 2012 on design guidance for bridges incorporating FRPs, and for inclusion in BD90 (the Highways Agency's design guidance for such bri
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Key Findings |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Potential use in non-academic contexts |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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Impacts |
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| Description |
This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk |
| Summary |
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| Date Materialised |
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Sectors submitted by the Researcher |
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This information can now be found on Gateway to Research (GtR) http://gtr.rcuk.ac.uk
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| Project URL: |
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| Further Information: |
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| Organisation Website: |
http://www.bris.ac.uk |