The oxidation and age-hardening propensities of eight widely varying petroleum asphalts used for paving were studied with and without hydrated lime, and with inert particulate matter in place of lime. The results show that oxidation of sulfides to sulfoxides and benzyl carbon to ketone is affected very little by the presence of lime. However, the addition of lime does inhibit age-hardening in asphalt whereas the inert particulate matter in the same amount and particle size has little effect other than the filler effect exhibited by the lime and the inert particulate.