Degree Type


Date of Award


Degree Name

Doctor of Philosophy


Civil, Construction, and Environmental Engineering


Civil Engineering

First Advisor

Ashley F. Buss


The research evaluates the effectiveness of chip seal treatments when rational design, good materials, good construction and good agency oversight work together. The work investigates the effectiveness of chip seal applications using short-term and long-term quantitative test results from various chip seal roadways located in Oregon. Laboratory testing is utilized to understand and reflect the importance of aggregate characterization to ensure the success of performance. Findings show that chip seal preserved Oregon’s roadways by improving their surface texture properties and protecting them from additional cracking and deterioration.

The study further evaluates the effect of various parameters on chip seal performance, such as: roadways’ pre-seal condition, traffic volume, material properties and design quantities. In addition, statistical analysis using split plot repeated measures design is introduced to better understand the significance of factors, such as type of seal and environmental aging, on the performance. The study identified that chip seal performance is mostly affected by three factors, which are: underlying road condition, pre-seal texture condition and seal type. Statistical analysis of macrotexture results showed that seal type (hot applied versus emulsified) and environmental-aging of pavements along with their interaction effect are the most significant factors that affected the roadways performance.

Finally, the study develops localized performance and survival prediction models for chip seals using two-years of 14 Oregon projects’ infield macro-texture data along with regression modelling. Findings reveal that chip seal treatments are estimated to extend the life of Oregon’s asphalt pavements by an average of 10 years.

Copyright Owner

Minas Guirguis



File Format


File Size

163 pages