Thesis
Developing laboratory testing procedures for commercial cold mix pothole patching materials
University of Iowa
Master of Science (MS), University of Iowa
Spring 2026
Abstract
Potholes represent a significant structural failure in flexible pavements, particularly in cold climates where freeze-thaw cycles accelerate surface degradation. While Hot Mix Asphalt (HMA) is the preferred material for permanent repairs, its limited availability during winter months necessitates the use of cold patch asphalt materials (CPAM). Despite their widespread use, there is a lack of standardized laboratory procedures to evaluate the performance of commercially available CPAM products, leading to inconsistent field results and high maintenance costs. This research aims to develop a reliable laboratory evaluation framework for CPAM by comparing three commercially available products: Quality Pavement Repair (QPR), Unique Paving Materials (UPM), and Patch Pack. The study transitioned from manual compaction, which proved statistically unreliable, to the use of the Superpave Gyratory Compactor (SGC) for specimen preparation. Performance was quantified through the Indirect Tensile Asphalt Cracking Test (IDEAL-CT) to determine fracture resistance, CTIndex, and a laboratory raveling test to measure surface durability.
Results indicated that Patch Pack achieved significantly lower air void contents (4-8%) and superior raveling resistance compared to the QPR and UPM mixes which used a more uniform aggregate. Furthermore, SGC compaction was found to significantly reduce variability in CTIndex measurements. This study establishes a performance-based methodology that enables transportation agencies to make data-driven material selection decisions, ultimately improving the longevity of winter pothole repairs.
Details
- Title: Subtitle
- Developing laboratory testing procedures for commercial cold mix pothole patching materials
- Creators
- Cameron Czupek
- Contributors
- Hosin Lee (Advisor)Paul Hanley (Committee Member)Asghar Bhatti (Committee Member)
- Resource Type
- Thesis
- Degree Awarded
- Master of Science (MS), University of Iowa
- Degree in
- Civil and Environmental Engineering
- Date degree season
- Spring 2026
- Publisher
- University of Iowa
- Number of pages
- xi, 131 pages
- Copyright
- Copyright 2026 Cameron Czupek
- Language
- English
- Date submitted
- 04/28/2026
- Description illustrations
- color illustrations
- Description bibliographic
- Includes bibliographical references (page 77-80).
- Public Abstract (ETD)
Potholes are more than just a nuisance; they are a major safety hazard and a costly problem for road maintenance. In states with cold winters that have frequent freeze thaw cycles, like Iowa and Illinois, potholes form when water gets under the road, freezes, and pushes the pavement up. When it thaws, a hole is left behind that collapses under the weight of cars.
Fixing these potholes in the winter is difficult because "hot" asphalt-the durable materials used in the summer-cannot be made when it is freezing outside. Road crews must use "cold patch" materials instead. However, not all cold patches are created equal, and there is currently no standard way for engineers to test them in a lab to see which one will last the longest.
This study tested three popular types of cold patch materials to find a better way to predict their performance. Using a machine called a Gyratory Compactor to squeeze the asphalt mixtures in the lab provided much more consistent results than the old method of hitting it with a manual hammer. We also found that asphalt mixtures that were able to be squeezed more tightly (creating fewer air pockets) stayed in the pothole much longer and didn't fall apart as easily. The findings of this research will help city and state engineers choose the best materials to fix our roads, saving tax dollars, and making driving safer during the winter.
- Academic Unit
- Civil and Environmental Engineering
- Record Identifier
- 9985176870402771
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