Structural behaviour of UHPFRC/concrete components under extreme actions

The objective of this project is to investigate the structural behaviour of composite structural components, consisting of ultra high-performance fibre reinforced concrete and conventional concrete, under high strain rates and high mechanical energy release.

Because ultra high-performance fibre reinforced concrete has excellent mechanical properties and effectively zero permeability, a logical application for this material is the construction of durable structural composite overlays to rehabilitate existing structural components made of conventional concrete. To formulate a practical basis for the design and dimensioning of such composite components, it is necessary to develop rational models of their structural behaviour.

The current focus of the work is on behaviour of the composite components under impact loading. The results of an extensive experimental program, consisting of both small and large-scale specimens, will be used to develop and validate analytical models. The experimental work consisted of the following three primary tasks:

1. Develop mix designs for ultra high-performance fibre reinforced concrete using locally available materials.
2. Test small scale plates consisting of ultra high-performace fibre reinforced concrete under impact.
   Small scale impact test frame and plate specimen (photo Katrin Habel)
3. Test larger scale composite slab strips consisting of conventional concrete, reinforced or prestressed, with a bonded overlay of ultra high-performance fibre reinforced concrete.
   Static load test of composite slab strip (photo Katrin Habel)

Analytical and numerical studies are currently underway using simple mass-spring models as well as the finite-element program VecTor2.

This project began in January 2005 and is currently underway.

This project is led by Dr. Katrin Habel.

Dr. Habel has been assisted by undergraduate students Jonathan Ho and Kiki Cheung.

Financial support for this project was provided by the following organizations:

• German Research Foundation (DFG)
• Natural Sciences and Engineering Research Council of Canada (NSERC)
• Bekaert Corporation (donation of materials for test specimens)
• Lafarge North America (donation of materials for test specimens)
• Degussa Admixtures Inc. (donation of materials for test specimens)
• Elkem Materials Inc. (donation of materials for test specimens)

Habel, K. and P. Gauvreau. 2006. Impact Behaviour of Concrete Bridge Deck Slabs with Composite Ultra High-Performance Fibre Reinforced Concrete Overlay. To be presented at the 7th International Conference on Short and Medium Span Bridges, Montreal.

Habel, K. and P. Gauvreau. 2006. Static and Impact Behaviour of Concrete Bridge Decks Rehabilitated with UHPFRC Overlay. To be presented at the Second Edition of the Symposium on Advances in Concrete Through Science and Engineering, Quebec.