A Potential New Structural Design for Flexible Pavement

Abstract

Throughout the history of pavement structure, the parallel layer structure has dominated the structural design of pavements. In other words, the entire road pavement share a uniform thickness design regardless how many lanes there are. However, due to traffic regulations and driving habits, the traffic flow most probably does not distribute evenly on a multi-lane road. Modern pavement design methods usually choose the lane that bears the heaviest traffic load as the design lane to determine the thickness design of the entire pavement. Hence there could be a certain over-design in the less trafficked lanes. This study aims to propose and evaluate a new structural design for flexible pavement by reducing the thickness of asphalt layers of the lightly trafficked lanes.
The traffic data of a real motorway in the Netherlands was analysed, based on which a new pavement structural design of a 3-lane road was established. Two finite element models, for both original and new designs, were established in CAPA-3D to calculate the stress and strain responses under different traffic load combinations. Following the Dutch design method the fatigue and deformation performance predictions of the two pavement designs were executed and compared. The results showed that the new design indeed improve the material cost-efficiency without compromising the performance of the pavement structure.
Taking advantage of the finite element models, a real-life simulation was also applied. The strain output of the simulation was used to calculate the rutting depth following the American design method. Both calculated rutting depth and the deformation output of the real-time simulation supported the earlier conclusions. An extra simulation of truck platooning was briefly executed and discussed as well.
Furthermore, the construction and maintenance feasibilities of the new design were explored. It was proved that the new design can be constructed by the existing equipment and machines. The current maintenance methods and procedures can also be applied to the new design.