Consideration of the permanent deformation of soils used in flexible pavement design

Abstract

The decreasing supply of soils with geotechnical parameters suitable for pavement designs is a problem. To establish more efficient designs and adequate construction criteria, it is essential to understand the performance of materials. In this work, the permanent deformation (PD) of soils used in pavement layers was studied using prediction models of PD and modulus of resilience in addition to the design of pavement structures using mechanistic–empirical and empirical methods. The multistage repeated load triaxial test was used along with numerical analyses of stresses and displacements using the CAP3D program. The results showed that both the test procedure and the prediction models satisfactorily obtained the PD behaviour. Moreover, designs using the methods adopted resulted in distinct structures (i.e. different thicknesses of granular pavement layers). From the results of this study, it was concluded that both the model and the test procedure show significant potential for characterising and modelling the PD of granular materials.