Cost-Effectiveness of Crack Sealing Materials and Techniques for Asphalt Pavements

Sealing or filling cracked asphalt pavements to prevent the intrusion of water into the pavement structure has long been an accepted practice of the Montana Department of Transportation. Attempts were made to establish the most economical and effective method of sealing pavement cracks for Montana and to better determine crack sealing’s role within Montana’s pavement management system (PvMS). Four experimental test sites were constructed within crack-sealing projects. The test sites included combinations of nine sealant materials and six sealing techniques. Monitoring of the test sites includes visual inspections (for all of the sites) and nondestructive structural readings and surface distress identification under Montana’s PvMS (for one test location). One expectation of the inspections is an estimation of crack sealing’s useful life. Information on project history and project methodology, including the methods used for evaluating the performance of sealed cracks, is presented. Interim conclusions are presented, most of which have been obtained from the two test sites that have been in service for 3 years. Similar performance has been observed for all materials with ASTM D5329 cone penetrations in excess of 90. In general, routing of transverse cracks improved the performance of the sealants. Routing did not appear necessary for centerline longitudinal cracks. Observations from the first year of service for the most recent installation are noted. Notably, router operators appear to prefer the shallow reservoir configuration over square reservoirs. The highest failure rates occur during the coldest period of the year, and much of this distress “heals” after exposure to the summer heat.