Impact of lime on the mechanical properties of HMA mixtures in Nevada

Over 5000 miles of pavements throughout the state of Nevada are maintained and rehabilitated by the Nevada Department of Transportation (NDOT). The pavements in the northern part of the state are subjected to cold environment and medium traffic while the pavements in the southern part of the state are subjected to hot environment and heavy traffic. Moisture damage occurs in all types of climates including hot, dry, and desert climates. This research differs from previous studies in several respects. First, because lime is used in HMA primarily for anti-stripping benefits, previous studies rarely quantified lime’s other performance benefits. Second, because testing is typically performed on only the HMA mix being considered for a project, and only as necessary to satisfy specifications, typical studies do not capture the full range of failure modes and environmental stresses. Furthermore, once specifications are met, test results are rarely translated into pavement performance characteristics. This research, by contrast, evaluated four typical HMA mixtures used by NDOT with the most widely accepted laboratory tests.