The visco-elastic multilayer program `VEROAD' is presented which does take into account the visco-elastic properties of the asphaltic mixes on the calculation of displacements, stresses and strains. VEROAD is an acronym for Visco-Elastic Road Analysis Delft. It models the asphaltic material visco-elastically and the load as a moving wheel. The time dependent displacements, stresses and strains (DSAS) can be obtained, as well as the permanent ones. The curves of both the longitudinal and transversal strains compare very well with those actually measured in full scale tests. Using the calculated DSAS the energy dissipated in a volume-element in the pavement can be obtained. This dissipated energy might be an indicator for initiation and growth of cracks. Also the permanent deformation can be obtained: the asphaltic layer which is most likely to deform can be found. In the paper the application of VEROAD for some actual problems is discussed. Emphasis is laid on the extra insight in the pavement constructions that is gained above using linear visco-elastic multilayer programs: time dependence of DSAS, permanent deformation and dissipated energy. (A)
Samenvatting