Viscoelastic-Plastic Model of Asphalt-Roller Interaction

Abstract

There are several factors that influence the quality of an asphalt pavement. While pavement design, material selection, and environmental parameters play a big role in the quality and useful life of the pavement, adequate quality control during the compaction process is also necessary to achieve the desired quality. Previous research has addressed the effect of material selection, pavement design and construction, and environmental factors on the long-term performance of asphalt pavement. However, very little work has been done to address the effect of the compaction process on the quality of pavement. A proper understanding of the interaction between the roller and an asphalt pavement is necessary to develop closed-loop control algorithms for intelligent compaction (IC) of asphalt pavements. While several variants of IC techniques are being offered in the market, there is a need for an accurate dynamical model of the compaction process to validate these methods. In this paper, a viscoelastic-plastic (VEP) model of an asphalt pavement is developed that can effectively represent the dynamical properties of the asphalt mat during compaction. This model is then integrated with a mathematical model of a vibratory compactor to study the response of the coupled system during compaction. The VEP model is based on Burger’s model and is used to represent the dynamical properties of the asphalt pavement. The parameters of the model are first estimated from the dynamic modulus master curves of the asphalt mix. These parameters are then continuously updated to accurately represent the properties of the asphalt mat during compaction. Detailed mathematical equations are developed that relate the changes in the asphalt mat to the vibratory response of the roller during compaction. Numerical simulation of the VEP model shows that the response of the coupled system can be used to study the compaction of asphalt pavements. Comparison of the simulation results with data gathered during construction of asphalt pavements indicate that this model could serve as a theoretical foundation for intelligent compaction of asphalt pavement.