1 Jul 2026

Development of High-Performance Cold Mix Asphalt for Asphalt Patching

Abstract: Cold mix asphalt (CMA) is commonly used to perform small asphalt patching repairs. It is readily available even when hot mix asphalt (HMA) is not due to distance from a plant or cold weather; it is convenient and can be kept on hand; and it can be used at ambient temperatures. Unfortunately, these advantages are generally offset by marginal performance, especially under heavy loads and at quick return-to-traffic times. For military airfields in particular, both logistical factors and adequate performance are critically important; typical CMAs cannot deliver both, and HMA is not always readily available. Consequently, the objective of this project was to develop a new high-performance CMA that combines convenience and logistical advantages of conventional CMA with the performance expected from HMA. This objective was met using an asphalt-modified polyurethane binder to design cold mix that far outperforms conventional CMA and rivals (exceeds, in some cases) HMA performance, based on both laboratory and full-scale field testing. This two-part material can be field mixed without special mixing equipment; once cured, it is highly elastic, exhibits little temperature sensitivity, and can withstand up to 300 passes of F-15E aircraft traffic with a 3 hr return-to-traffic time (1 in. rutting threshold).