New Project: Long-Term Field Performance Evaluation of Chip Seals

Chip seals are an economical road surface treatment that MnDOT and counties use to enhance existing pavement performance and service life. A thin layer of asphalt emulsion sprayed on the pavement surface and mixed with aggregate chips can address minor pavement distresses and seal the pavement surface to reduce the impacts of further wear.

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Applying a chip seal at the optimal time results in the greatest life-extending benefits for road surfaces. Additionally, the condition of the existing pavement impacts the protective effects and performance of the chip seal treatment.

Understanding the relationship between the long-term performance of a chip seal and the circumstances under which it was applied is critical to obtaining the maximum benefit of this treatment. Choosing appropriate projects for chip seal application and the right timing of the application will result in more cost-effective and sustainable pavements.

“This research will provide needed information regarding the ideal conditions for chip seal application to result in the best performance,” said Joel Ulring, pavement preservation engineer, MnDOT Office of Materials & Road Research. “Knowing the best time for chip seal treatment application supports our goals for better quality and longer-lasting pavement.”

Objectives

In a new project, researchers will analyze data on the long-term performance of multiple chip seal test sections applied by local transportation agencies to determine the treatment’s impacts on pavement aging and the optimal timing of an application.

The objectives are:

Compile and summarize pretreatment condition, construction and chip seal application information for pavement test sections
Analyze performance data collected since chip seal application
Collect asphalt cores from treated and untreated test sections, and investigate material properties
Determine the optimal time for chip seal application based on performance data and lab results