UNIVERSITY OF NOTTINGHAM
RESEARCH STUDENT: Dr Stuart Dunhill
START DATE: 1st October 1998
END DATE: 30th September 2001
FUNDING: NARC: £19,800
Other: £31,966
TOTAL: £51,766

Project Description
The theme of this research project was to investigate an d develop pavement performance models for the two main forms of bituminous pavement deterioration, namely, permanent deformation and fatigue cracking. This was accomplished by using a visco-elastic-plastic constitutive model, which could be implemented in the Finite Element (FE) package CAPA-3D. The project focused on the quasi-static characterisation of two typical UK bituminous mixtures using monotonic uniaxial compression and tension tests and the determination of the material parameters needed for the constitutive model.

Outcomes from the Project
The main deliverables from the project were:

· Development of a monotonic uniaxial compression test for cylindrical asphalt mixture specimens;
· Development of a monotonic uniaxial tension test for dog-bone shaped asphalt mixture specimens;
· Quasi-static material characterisation (over a range of temperatures and displacement rates);
· Data reduction for implementation in the CAPA-3D model.

Papers
The following papers have been generated from the research:

1. Dunhill, S.T., Airey, G.D., Collop, A.C. and Brown, S.F. 'An Investigation into the Deterioration Mechanisms of Lightly Trafficked Roads.' Proceedings of the 2nd Eurasphalt and Eurobitume Congress, Vol. 2, pp 122-128, Barcelona, 2000.
2. Airey, G.D., Dunhill, S.T. and Collop, A.C. 'A Constitutive Material Modelling Methodology for Asphalt Mixtures.' Ninth International Conference on Asphalt Pavements, Copenhagen, 2002.
3. Airey, G.D., Dunhill, S.T., Collop, A.C. and Scarpas, A. 'Determination of Constitutive Model Parameters to Simulate Asphalt Mixture Response.' 6th International RILEM Symposium on Performance Testing and Evaluation of Bituminous Materials, PTEBM'03, Zurich, 2003.