Advanced Pavement Design: Finite Element Modeling for Rigid Pavement Joints, Report II: Model Development

The contribution of a cement-stabilized base course to the strength of the rigid pavement structure is poorly understood. The objective of this research was to obtain data on the response of the rigid pavement slab-joint-foundation system by conducting laboratory-scale experiments on jointed rigid pavement models and to develop a comprehensive three-dimensional (3D) finite element model of the rigid pavement slab-joint-foundation system that can be implemented in the advanced pavement design concepts currently under development by the Federal Aviation Administration. Evidence from experiments conducted on six laboratory-scale jointed rigid pavement models suggests that the joint efficiency depends upon the presence and condition of a stabilized base. The presence of cracking in the base and the degree of bonding between the slabs and the stabilized base course influence the structural capacity and load transfer capability of the rigid pavement structure. The finite element model developed in this research indicates that a comprehensive 3D finite element modeling technique provides a rational approach to modeling the structural response of the jointed rigid airport pavement system. Modeling features which are required include explicit 3D modeling of the slab continua, load transfer capability at the joint (modeled springs between the slabs), explicit 3D modeling of the base course continua, aggregate interlock capability across the cracks in the base course (again, modeled by springs across the crack), and contact interaction between the slabs and base course. The contact interaction model feature must allow gaps to open between the slab and base. Furthermore, where the slabs and base are in contact, transfer of shear stresses across the interface via friction should be modeled.