Modeling the dynamics of asphalt-roller interaction during compaction

Compaction is one of the important steps in pavement construction that significantly affects the quality and long-term performance of asphalt pavement. Compaction of asphalt pavement is influenced by several factors related to the environment and the properties of asphalt mixture. Therefore, continuous control of compaction effort is needed in order to obtain adequate density uniformly throughout the pavement. Limited understanding of compaction dynamics and lack of a computationally tractable mathematical model hamper the development of such continuous feedback control technologies. In this paper, a lumped element-based dynamical model is developed to study the interaction between a moving vibratory roller and the underlying asphalt pavement. The asphalt pavement is represented as a collection of blocks of mechanical elements with viscoelastic-plastic properties. The vibration of the roller drum, its movement along the pavement, and its interaction with the asphalt mix is formulated. The effect of pavement temperature, layer thickness, loading frequency, and volumetric properties of asphalt mix on the mechanical behavior of the pavement is incorporated in the model. A procedure is then presented to estimate the parameters of the model from a standard laboratory complex modulus test. The model is used to numerically simulate the compaction of two different types of asphalt mixes and the results are compared with the corresponding results observed during field compaction. Analysis of the results shows that the proposed model can emulate the vibratory response of the drum observed during field compaction. The results also indicate that the model is able to replicate the pass-by-pass densification process during field compaction.