Effective Timing for Two Sequential Applications of Slurry Seal on Asphalt Pavement

Abstract

This study evaluated the field performance of asphalt pavements with two sequential slurry seal applications, developed per- formance models for asphalt pavements without slurry seals and asphalt pavements receiving slurry seals at various times following con- struction, and identified the optimum time for the application of two slurry seals on asphalt pavements within the Washoe County, Nevada, region. This is a continuation of a previous study in which a single application of slurry seal was investigated. The MicroPAVER system was used to evaluate the long-term pavement performance data collected for the last 15 years and the cost-effectiveness of slurry seals applied to new and existing flexible pavements at 0, 1, 3, 5, 7, and 9 years after construction. The data generated in this study clearly reveal an optimum time window for slurry seal application. The optimum times and highest relative benefit of application of slurry seals for both overlaid and newly constructed pavements were when the first slurry seal was applied at 3 years after construction, followed by a second slurry seal at year 7 or 9. Accordingly, it was recommended to apply the first slurry seal for newly constructed and overlaid pavements, respectively, when the pavement condition index (PCI) is 90 and 87, followed by a second slurry seal when the PCI reaches a value of 86 and 77. DOI: 10.1061/ (ASCE)TE.1943-5436.0000521. © 2013 American Society of Civil Engineers. CE Database subject headings: Slurries; Asphalt pavements; Maintenance; Benefit cost ratios. Author keywords: Slurry seal; Optimum time of application; Pavement preservation; Maintenance; Performance model; Pavement condition index; Cost-benefit ratio.