Interface behavior of partial depth repair for airport concrete pavement subjected to differential volume change

For partial depth repair of airport concrete pavement, the thickness and physical properties of the materials used in the repair project are the prerequisite for the success of the repairing works. While under most actual constructions, these two factors are always regarded as the focus of the project, which leads to the re-damage of the repaired section once again. The repaired concrete pavement can be easily re-failed due to the incompatibility between the repair materials and the matrix concrete for their different characteristics in the aspect of thermal expansion and drying shrinkage. In general, the mechanistic model is used to calculate the interface stress by drying shrinkage and thermal expansion. However, the interface stiffness cannot be figured out by this way. In this study, the interface stress was calculated by the volume change of three kinds of repair materials which were Styrene Butadiene Rubber Concrete (SBR), Polymer Concrete (PC) and Coarse Aggregate Polymer Concrete (CPC). Besides, the characteristics of the interface behavior was also analyzed from the aspect of the interface slip and the shear stress. In the end, the calculation method for the interface stiffness was proposed. The procedure can be used in design. The slip range of these three sorts of repair materials is indicated by the test results of this study as follows, 900-1500 μm for SBR, 3000-9000 μm for PC and 6000-15,000 μm for CPC, and the interface stiffness of each material is 110.44 N/mm3, 45.65 N/mm3 and 10.58 N/mm3 respectively.