Asphalt Pavement Cracks And Trenches Maintenance

This thesis focuses systematic and comprehensive study on distress causes, repair mechanisms, patching materials and maintenance procedures in relation to cracks and potholes, the two most commonly seen distresses in asphalt roads.A most sophisticated classification is made to the geometric shapes and distress causes of cracks and potholes as well as to their sizes and degrees of damage. A deepened analysis is offered to damage mechanisms typical of cracks and potholes in six and four categories respectively. And an analytical research is conducted on crack filling and repair mechanisms, on the basis of which specific requirements on maintenance effects are put forward. Moreover, analysis done to the re-distress causes of filled cracks and repaired potholes aims at acquiring when is the proper time to fill cracks in comparison with some other time to fill them up. In order to ensure the density degree and the level degree of repaired potholes, this thesis presents loose pavement coefficient method and material capacity method to control the accurate feel amount of patching materials.This thesis for the first time bases its analysis on the maintenance characteristics and repair mechanisms for crack filling and pothole repair in asphalt roads. It analyzes the properties of the aggregate and the bituminous binder in patching materials, and further analyzes the compatibilities of the aggregate and the bituminous binder, patching materials and old pavement materials. Furthermore, it determines the grading types, the mineral aggregate gradations, the application rate of asphalt, the principle of selecting component materials and the air void.This thesis also first presents the most straightforward and the most effective evaluation indexes on the qualities of crack filling and pothole repair, compares and analyzes the properties, the applicable situations, the strong and the weak points of crack filling materials (such as hot asphalt cement, emulsified asphalt, modified asphalt, etc.) and pothole repair materials (such as hot-mix asphalt mixture and cold-mix asphalt mixture). On the basis of the permanent demands on repair, this thesis sums up and lists the maintenance steps in crack filling and pothole repair, and advances the procedure designs to be directly adopted by maintenance workers of asphalt roads.Finally, this thesis creatively presents the new repair procedure of the static hot-compacted method, and proves its feasibility and adaptability through theoretical analysis and experimental researches.