Research on maintenance time for functional preventive materials in asphalt pavement

In order to improve the effectiveness of preventive maintenance for asphalt pavement, the optimal maintenance time of functional preventive maintenance materials in asphalt pavement was studied. Three kinds of asphalts were chosen and aged by 20, 40, 60 and 80 hours in pressure aging vessel to simulate the long-term aging of asphalt binder. Meanwhile, asphalt binders were recovered from five asphalt pavements located in Hubei province. Then, the change laws of rheology cracking index and carbonyl area index of both aged asphalt and recovered asphalt were studied. The results indicate that rheology cracking index has linear relationship with ductility of asphalt binder. The rheology cracking index can be used to predict the ductility of asphalt binder in actual pavement. The critical value of ductility related to cracking is defined as 5-8 cm, and the ranges of rheology cracking index and carbonyl area are determined. These two indexes can provide reference for the optimal preventive maintenance time for asphalt pavement.