الفهرس 
CHAPTER ONE : INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
Jointed plain concrete pavements are commonly constructed at taxiways, runways and aprons of many airports around the world. Many computer response models based on the finite element method have been developed for the analysis of jointed pavement slabs. However, important considerations were overlooked. Such as neglecting the combined effect of dynamic traffic loads and thermal gradient, neglecting the modeling of dowel bars or their effect using beam or spring elements, the sliding characteristics between dowel bars and the surrounding concrete. As well as the friction at the interface between the concrete slab and base course, the influence of dynamic loads on the response of rigid pavements was also neglected .
The Federal Aviation Administration (FAA) uses a mechanistic design procedure for the design of rigid airport pavements. The FAARFIELD (FAA Rigid and Flexible Iterative Elastic Layer Design) procedure is based on layered elastic and three-dimensional finite element-based structural analysis, which developed to calculate design thicknesses for airfield pavements. The design procedure assumes constant stress based load transfer efficiency (LTE) of 25% at the joints. FAARFIELD does not consider curling stresses in determining the Portland Cement Concrete (PCC) layer thickness. The curling stresses, induced due to the temperature differentials at the top and bottom of the PCC slab, can lead to higher combined stresses (loading plus curling) in pavements and can affect the load transfer efficiency at the joint, variations in environmental conditions, loading characteristics, type of joint and pavement material properties can affect load transfer efficiency.
The objective of this study was to develop Three-Dimensional Finite Element Models (3D-FEM) that can be used to investigate the separate or combined effect of moving aircraft axle loads and thermal gradient on the response of dowel Jointed Portland Cement Concrete Pavement (JPCCP) structures. The availability of a tool that can be used for an accurate prediction of rigid pavement response to such loads would enable designing longer lasting pavements and understanding some of its modes of distress. Finite element modeling offers a powerful tool for the simulation of the structural behavior of pavements under the effect of combined moving axle loads and thermal gradient. The developed model provides a comprehensive view of the variation in pavement response as the axle loads across the transverse joint and traverse the concrete slab under several aspects related to pavement geometry, material properties, thermal gradients, and aircraft axle load and configuration. Also related to dowels as material properties, geometry, configuration in pavement slab, bond to concrete and stiffness of the joint for understanding the behavior of rigid airfield pavement.