Strain energy release rate at interface of concrete overlaid pavements

Abstract

A new method for calculating energy release rate (ERR) at the interface of concrete overlaid pavements is proposed using crack closure and the nodal force technique. This method transforms a 3D pavement system into a 2D interfacial crack model via a theoretical conversion. The interfacial ERRs of steel fibre-reinforced, roller-compacted, polymer-modified concrete overlay pavement subjected to vehicular load were calculated and compared with the measured interfacial fracture toughness of the bi-material. It was found that the ERRs considerably decrease with the increase in overlay thickness and elastic modulus of foundation. Thin overlays (less than 100 mm) should not be considered in overlay pavement design to avoid interfacial delamination induced by heavy vehicular loading. For a typical overlay pavement system subjected to complex vehicular loads, an interfacial crack suffers mainly from damage due to mode-I, opening, compared to mode-II, sliding, while mode-III, tearing damage is negligible.

Keywords:

• Concrete overlay pavement
• interface fracture
• strain energy release rate

Acknowledgements

The financial and in-kind support of Aggregate Industries UK Ltd is gratefully acknowledged. The authors would also like to thank Tarmac AGS Mineraux, Power Minerals and Nippon Gohsei EU, for providing a number of materials for research.

Funding

This work was supported by EPSRC (Engineering and Physical Sciences Research Council) [grant number 08002550].