STRUCTURAL AND TECHNOLOGICAL PECULIARITIES OF ASPHALT PAVEMENT CRACK SEALING

Abstract

In Ukraine a significant part of motor roads with flexible pavement, especially local ones, serves with cracks in asphalt concrete layers during long period. Asphalt concrete spalling in the zone of open crack edges is a further stage of pavement layer deterioration during its long period of service. Costs for repair of these defects are much higher than for crack sealing. Monitoring of actual condition of flexible pavements in various regions of Ukraine indicates that cracks in asphalt concrete pavement appear in different locations, have different direction and pattern, width, depth and length. Number of cracks, their frequency of location on the pavement, length and width of opening at low temperatures depend on duration of the pavement exploitation. Today there are no exact regulations on structural and technological decisions in terms of crack preparation and sealing with regard to their width and activity in normative and technical documents. The topic of the paper is development of structural and technological decisions for crack preparation and sealing in asphalt concrete pavements with regard to their width and activity. It is noted that hot-applied bituminous sealing materials are the most popular in Ukraine for works on crack sealing in asphalt concrete road pavements. Based on the results of scientific and technical supervision of various crack sealing techniques in asphalt concrete road pavements it is shown that crack sealing can be performed with preliminary routing (rectangular rout) in zone of crack or without routing. It is noted that cracks with preliminary routing can be sealed with overband or without overband of sealing material on the surface of asphalt pavement. Technique of crack sealing by filling of the created rout with bitumen-polymer mastic or hot-applied sealant with overband on asphalt pavement surface provides the highest watertightness and durability of the sealed crack, in comparison with sealing by filling of the created rout flush with asphalt pavement, or without routing. Classification of cracks in asphalt concrete pavements is proposed and structural and technological decisions on crack preparation and sealing are described.