Calculative method of effective induction heating depth and its influences on induction healing of dense-graded asphalt pavement

Abstract

Induction heating technology has been widely used in the induction healing of dense-graded asphalt pavement (DGAP). It’s realized by heating the inductive materials under the electromagnetic field. The induced healing efficiency is related to the effective induction heating depth (EIHD) of inductive materials. Nevertheless, In the existing studies, the EIHD was defined by the temperature method, which is inaccurate and sensitive. Also, the relationship between EIHD and the induced healing efficiency of DGAP has not been investigated. Therefore, in this study, the heat generation and heat conduction processes of DGAP internal material were analyzed, and the EIHD was defined as the main heat generation area of inductive materials. After establishing the 2-D induction heating model of DGAP, to determine EIHD, the thermal energy of different materials in DGAP was calculated in layers by temperature measurements based on meshing. Additionally, induction heating experiments were conducted to verify the correctness of the method. At last, the relationship between EIHD and the induced healing efficiency of DGAP was found by induction healing tests. The results show that the energy-based calculative method is more accurate than the traditional temperature method. Besides, the relationship between EIHD and the overall average healing ratios of DGAP is accorded with a positive linear correlation, and the gradient healing alleviates with the increase of EIHD. This paper proposes a calculative method of EIHD in DGAP and reveals the relationship between EIHD and induced healing behaviors, which can promote the development of pavement maintenance technology.