Measurement and Correction of Interface Shear Stiffness between Slab and Base for Concrete Pavement

Abstract

Interface parameters could affect the adhesion and durability performance of cement concrete pavements. In order to improve the pavement performance, the interface shear stiffness between the slab and the base of concrete pavement were investigated accurately. A horizontal shear tester was developed which could simulate the vertical pressure. The bond-slip curve of the specimens that the interface treated by three different measures was determined, such as emulsified asphalt, geotextile and asphalt concrete. Then, the correction of interface vertical pressure was made for average shear stiffness based on simple iterative method, and the equivalent shear stiffness of three types of specimens was recommended. The results showed that the specimen treated by emulsified asphalt required the maximum shear force, and asphalt concrete was minimum during the static friction stage. The contact states between slab and base are significantly correlated with the interface treatments. So, the interface treatments selection needed to find a balance between flexural tensile stress and thermal stress of the slab. In the sliding friction stage, the shear resistances of three types of interface treatment methods were significantly weakened and the average shear stiffness declined dramatically. It is very different for interface shear stiffness when the pavement structure in different using stages. The interface parameter must consistent with the using state of the pavement during the analysis process of the pavement structure.