Mechanical Properties of Concrete Pavement with Different Isolation Layers on Lean Concrete Base

摘要

With increasing traffic volumes and higher wheel loads, the structures of Cement Concrete Pavement (PCC) with lean concrete base (LCB) have been used widely in China. However, reflection cracking is one of the primary distresses in PCC on LCB. Although bond breaker mediums have been utilized with success to reduce and minimize undesirable cracks reflecting from lean concrete bases, the mechanisms of delaying or/and reducing reflection cracking propagation have yet to be fundamentally understood. In this paper, with the basic parameters obtained from Qing-Lian highway, three-dimensional FEM considering contacts between layers was utilized to analyze the pavement systems with different bond breaker media. It was found that pavement performance is less favorable under wheel loading when there is a good bond breaking. However, the pavement performance is more favorable under thermal loading when there is a good bond breaking. A good bond breaking is essential for PCC on LCB as the undesirable cracks are the results of the thermal loading. Based on this study, it was found that wax can be used effectively to reduce the tensile stresses at the interface between PCC slab and LCB such that the erratic cracks due to the temperature variations can be minimized.