Modeling analysis of pavement layer interface bonding condition effects on cracking performance

The structure of asphalt pavements are characterized by composition of pavement layers. Previous research has suggested that the bond conditions between pavement layers significantly affect the cracking performance. Open Graded Friction Course (OGFC), which is widely used in Florida, was generally considered as a function course and has lower cracking resistance. While for the top-down cracking, OGFC may be the first front in resisting the cracking. The primary objective of this study is to develop a model to evaluate the effects of interface bonding conditions on top-down and reflective cracking performance.;Continuum and multi-scale modeling of the pavement structure were conducted for different layer combination and bonding conditions. The FEM modeling is implemented with Florida HMA Fracture Mechanics to evaluate the effects of bonded interface on cracking performance. It was found that the OGFC with a poor bond such as the conventional tack coat may reduce the cracking resistance of the structure. A well bond between the OGFC and underlying layer may result in a better cracking performance. It was determined in the multi-scale analysis that the interface affects the cracking performance by affecting the stress transmission through the interface in the pavement structures. The continuum model of the pavement structure with different bond conditions indicates that the different bond conditions may lead to totally different stress distribution in the pavement layers. Pavement with NovabondRTM as bonding agent has higher cracking resistance than the pavement with conventional tack coat as bonding agent.;The modeling of composite specimen tests was performed to investigate the mechanism of the bonding effects on top-down and reflective cracking performance. Different bonding conditions were assumed due to the different application rate and type of the bonding agent. The modeling results show agreement with test results. The model and the assumption were considered reasonable. Novabond RTM was determined has a positive effect on top-down and reflective cracking performance. The model clearly proved that the interface bonding conditions have significant effect on cracking performance. (Full text of this dissertation may be available via the University of Florida Libraries web site. Please check http://www.uflib.ufl.edu/etd.html).