The military services have a great number of asphalt pavements that are subject to fuel spillage, including fueling, parking, and maintenance areas. Coal-tar emulsion sealer mixtures are commonly used to protect these asphalt pavements. Since the performance of the coal-tar searlers has been disappointing in many cases, investigations into improving the perofmrance continue. Therefore, a field test section using various mixtures was built and evaluated for about a year. The same materials and mixtures were evaluated in the laboratory. The field performance of the coal-tar emulsion varied greatly between two different manufacturers. The measurement of performance was the amount and size of cracks that occurred within each section. One emulsion experienced a much greater amount of cracking, when compared to the other emulsion. For bot emulsions, higher amounts of aggregate provided improved field performance. With one emulsion, the addition of a polymer improved the field performance. Laboratory evaluations showed that increasing the amount of aggregate will make the mixture permeable and therefore not as fuel resistant. This evaluation also indicated that polymer additives provided decreased creep stiffness or increased sealer flexibility in both non-aged and aged mixture samples.
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