Within the past two decades, various warm mix asphalt technologies (WMA) have been Introduced with the goal of mix production at lower temperature as compared to the traditional hot mix asphalt (HMA). Effect of the WMA additives on the rheology of binders and mechanical properties of the mixes have been well Investigated by several researchers. However, studying the effect of age hardening on the mechanical properties of the compacted WMA has not been adequately researched. This paper presents the results of an experimental study on changes in shear and Young's dynamic modulus of three popular WMA technologies in the United States as well as a control HMA over a period of four years. To this end, small scale cylindrical specimens were prepared and studied in the laboratory. A chemical additive, a wax-based additive, and water foaming process were utilized in preparation of the specimens. The specimens were tested for properties at various time intervals. Modulus was measured right after preparation and laboratory short term conditioning, then at subsequent intervals after production: two years, and four years. The results indicate different trend of hardening with respect to the modulus across the technologies within the range of this study. Impact resonance (IR) tests at three temperatures of 10, 25, and 40°C were conducted on the replicates to non-destructively measure the shear and Young's modulus values of the specimens. IR results indicate that the trend of changes in modulus with time is different among the mixes.