The development and application of an interfacial cohesive zone model of the pavement interlayer considering the characteristics of adhesive materials

The interlayer adhesive material is important to ensure the integrity of a pavement structure, but its influence on pavement performance as an actual material layer is usually ignored in pavement structure design and analysis. At present, the relationship between the shear stress and slip is usually expressed in the form of a coefficient. The interlayer adhesive material is a kind of heterogeneous composite material with rheological performance. Therefore, the relationship between a force and the displacement cannot be characterized by a simple linear relationship. In this paper, we develop a method for characterizing the properties of interlayer bonding materials using an interfacial cohesive zone model. First, we perform experimental tests, that is, a pull-out test and an oblique-shear test, to determine the optimal dosage of adhesive material, and then obtain the normal stress-displacement characteristic curve and shear stress-displacement characteristic curve for the optimal dosage of the adhesive material. Then, we divide the shear stress-displacement characteristic curve into four stages. Next, based on the characteristics of normal stress displacement curve and shear stress displacement curve, we develop a cohesive zone model based pavement interlayer simulation approach that can be used to characterize the stress displacement characteristics of interlayer adhesive materials. Finally, we present the performance of the interfacial cohesive zone model using finite element software to simulate the shear test and pull-out test, and find that the simulation results are basically consistent with the experimental results. Further, we apply the model to a special case, and the results are also consistent with the actual monitoring. It shows that the proposed method is reasonable.