The aim of the study is to compare flexible pavement design lifespans and the main factors which create their values for a standard structure and one with an anti-fatigue course AF at different parameter values of pavement and its load, relevant to their design processes. Depending on the mixture used for the anti-fatigue course or the course thickness, durability improvement of the pavement (compared to the durability of a standard structure) can be obtained by extending the design lifespan of the asphalt base course or by extending the design lifespan of the AF course. On sections with predominantly slow traffic, the lifespan decreases significantly compared to sections with typical vehicle speed – the relative decrease is greater if anti-fatigue course is applied.
The paper presents a numerical study of an aircraft wheel impacting on a flexible landing surface. The proposed 3D model simulates the behaviour of flexible runway pavement during the landing phase. This model was implemented in a finite element code in order to investigate the impact of repeated cycles of loads on pavement response. In the model, a multi-layer pavement structure was considered. In addition, the asphalt layer (HMA) was assumed to follow a viscoelastoplastic behaviour. The results demonstrate the capability of the model in predicting the permanent deformation distribution in the asphalt layer.
In the flexible road pavement design a mechanistic model of a multilayered half-space with linear elastic or viscoelastic layers is usually used for the pavement analysis. This paper describes a domain selection for the purpose of a FE model creating of the linear elastic layered half-space and boundary conditions on borders of that domain. This FE model should guarantee that the key components of displacements, stresses and strains obtained using ABAQUS program would be in particular identical with those ones obtained by analytical method using VEROAD program. It to achieve matching results with both methods is relatively easy for stresses and strains. However, for displacements, using FEM to obtain correct results is (understandably) highly problematic due to infinity of half-space. This paper proposes an original method of overcoming these difficulties.