Behaviour models for UGM using cyclic tri-axial tests

The behaviour of unbound granular materials (UGM) on pavement granular layers, in spite of several studies already performed on this matter, is not enough characterized, especially under Portuguese conditions due to reasons connected to the heterogeneity of the rock masses from which they come from. In the attempt of contributing for a better knowledge of that behaviour, a research programme is currently underway with the main objective being the mechanical characterization and the establishment of behaviour models for two types of crushed materials i.e. granite and limestone, susceptible of being used as unbound base and sub-base of Portuguese road pavements. This paper describes the results found to date showing the differences and the meeting points with some previous studies on similar materials conducted with other approaches and pointing out the main directives that can be extracted in terms the global behaviour of pavements