Life-Cycle Cost Analysis of Mitigating Reflective Cracking

Abstract

Reflective cracking is a major and costly problem in many countries. It occurs in the top (overlay) layers above existing cracks in the lower (existing) pavement. This type of cracking can lead to premature deterioration of the pavement structure through the infiltration of moisture and debris. Although extensive research has been directed toward mitigation of the problem, work needs to be done, as it still appears to be a major problem. The problem is related in part to the fact that most of the work being done involves rehabilitation. One of the most common types of pavement rehabilitation is the use of an asphalt overlay. The focus of the present analysis is the economic benefits of reducing and treating reflective cracking before the placement of an asphalt overlay. A methodology for converting crack spacing to roughness is also presented. This information is used to examine how cracking is related to the measured international roughness index values. A model relating the amount of cracking to the loss of serviceability or a reduction in service life is presented. That model indicates that a reduction of transverse crack spacing from 5 to 20 m should result in a 5-year extension of service life, with a cost savings of $25,000 (2002 U.S. dollars) per two-lane kilometer. Measurement and treatment of cracking can also yield significant benefits. Benefit–cost ratios from the measurement of cracking can range from about 5 to 50, while proper and timely crack treatment (routing and sealing) can result in an extension of pavement life by 2 years and cost savings of $7,000 per lane kilometer.