Laboratory Investigations of Cold Mix Asphalt for Cold Region Applications

Abstract

Abstract Cold mix asphalt (CMA) can be a quick, environmentally friendly, and low-cost option for utility-cut backfilling on urban streets and most highway agencies prefer it as a pothole patching and pavement surface repairing material over hot mix asphalt (HMA) during winter and wet seasons. However, applying poor quality CMA may result in premature patching and backfilling failures, reduce pavement’s integrity and longevity, and impair drivers’ safety. Additionally, CMA’s lack of stability and durability while exposed to heavy traffic, moisture, and freeze-thaw conditions may accelerate further deterioration. This paper focused on evaluating and comparing twelve CMAs through laboratory tests to determine properties that may cause poor performance in cold climatic regions. Taking into consideration the identified CMA distresses, this study conducted Marshall Stability and flow, indirect tensile strength (ITS), cohesion, and adhesiveness tests on nine proprietary and three conventional cold mixes, including both open- and dense-graded materials. Most mixes had low adhesion properties and high sensitivity to freeze-thaw cycles. An analysis of variance showed that aggregate grain size distribution and bitumen content had a significant effect on CMA’s performance.