Abstract:
A 3D finite element analysis was conducted on several models of conventional and
perpetual pavements to assess the similarities and differences in their structural and
fatigue response when both pavement types are subjected to varied axle load and wheel
configurations. The models were designed as a five-layer pavement system made up of an
asphalt surface laid on an asphalt binder course. The base used was a graded crushed
stone of G1 quality. Asphalt materials were assumed to be viscoelastic, while the granular
base, subbase and subgrade were assumed to be linearly elastic. All material properties
conformed to the South African Mechanistic Design Method (SAMDM) Guideline. Tandem
axle dual wheel loading produces the least safety factor and fatigue life, and the highest
damage among other configurations. Perpetual pavement models from the same materials
were found to be more structurally rigid when comparing strains and damage in the long
term. They show more resistance to distress by traffic loading when compared to
conventional pavements. It was concluded that a 3-Dimensional Finite Element Analysis
(FEA) is a suitable tool for supporting Mechanistic-Empirical design methods and provides
a platform for further investigation of the behaviour of perpetual pavements.
