Dynamical Model of Asphalt-Roller Interaction During Compaction Syed Asif Imran 1 , Fares Beainy 2 , Sesh Commuri 1 and Musharraf Zaman 3 1 School of Electrical and Computer Enginnering, University of Oklahoma, W. Boyd St, Norman, Oklahoma, U.S.A. 2 Volvo Construction Equipment, Volvo Way, Shippensburg, Pennsylvania U.S.A. 3 School of Civil Enginnering and Environmental Science, University of Oklahoma, W. Boyd St, Norman, Oklahoma, U.S.A. Keywords: Intelligent Compaction, Vibration Analysis, Asphalt Pavements, Roller Dynamics, Construction Engineering. Abstract: Proper and uniform compaction during construction is of utmost importance for the long term performance of asphalt pavement. Variations in the conditions of freshly laid pavements require adjustment of the compaction effort in order to obtain uniform and adequate density. One of the goals of on-going research in Intelligent Compaction (IC) is the development of adaptive feedback control mechanism to adjust the compaction effort according to the field and pavement conditions. Such feedback control systems require a good understanding of compaction dynamics. In this study, a dynamical model is developed to study the interaction between a moving vibratory roller and the underlying asphalt pavement during compaction. The asphalt pavement is represented as a lumped element model with visco-elastic-plastic properties. A procedure is presented to estimate the parameters of this model from standard tests on asphalt mix conducted in the laboratory. The combined roller-pavement dynamical model is used to replicate field compaction of an asphalt pavement using a vibratory roller. Numerical simulation results indicate good agreement with results observed during compaction of pavements in the field. Comparison between the simulation results and the results collected from the actual pavement construction job show that the model could be used as a mathematical basis for the development of advanced compaction methods. 1 INTRODUCTION Compaction is one of the important steps in pavement construction that affect the quality of asphalt pavement. Proper compaction increases the load bearing capacity of the pavement and provides a smooth riding surface. It also increases the useful life of a pavement by reducing its susceptibility to early failure due to fatigue, rutting, low temperature cracking and aging (US Army Corps, 2000). The construction of an asphalt pavement begins with the preparation of the base and subsequent laydown of asphalt mix of desired thickness. Rollers with rotating eccentric masses in the drum are then used to impart static and vibratory energy to the asphalt mat to reduce the air voids and improve the stiffness of the pavement. Several factors like the composition of asphalt mix, its temperature at laydown, thickness of the layer, temperature and stiffness of the underlying layer, temperature, velocity and humidity of air, and solar radiation levels affect the compactbility of asphalt mix (Brown et al., 2009). Unless these factors are addressed during the construction process, they can lead to non-uniform compaction of the pavement. Intelligent Compaction (IC) technologies are being developed to provide continuous real-time quality control by monitoring the level of compaction of the pavement and adjusting the amount of compaction energy applied by the roller in order to obtain uniform stiffness/density. One of the goals of IC is to develop an automatic feedback control system that can take into account compaction quality and modify in real time, roller parameters such as speed, frequency and amplitude of vibration, to improve the overall quality of the construction (Chang et al., 2012). Intelligent Compaction is based on the hypothesis that the vibratory roller and the underlying pavement layers form a coupled system. The response of the roller is determined by the frequency of its vibratory motors and the natural vibratory modes of the coupled system (Imran et al, 2012). Compaction of the pavement increases its stiffness and as a result, the vibrations of the compactor are altered. The 559 Imran S., Beainy F., Commuri S. and Zaman M.. Dynamical Model of Asphalt-Roller Interaction During Compaction. DOI: 10.5220/0005066905590567 In Proceedings of the 11th International Conference on Informatics in Control, Automation and Robotics (ICINCO-2014), pages 559-567 ISBN: 978-989-758-039-0 Copyright c  2014 SCITEPRESS (Science and Technology Publications, Lda.)