A LABORATORY STUDY OF AN ORGANIC WARM MIX ASPHALT ADDITIVE ON AGING CHARACTERISTICS OF BITUMINOUS MIXTURES

In recent years, researchers have been conducting studies in order to discover new alternative technologies for hot mix asphalts. These new technologies are expected to be higher in performance, lower in costs, sustainable over natural resources, environmentally friendly and easy to apply. With utilization of warm mix asphalt technologies, it is possible to decrease mixing and compaction temperatures of asphalt applications. In warm mix asphalt pavements, it is expected that ageing induced failures be less than hot mix asphalt pavements due to lower application temperatures. Within the scope of this study, the effects of an organic warm mix asphalt additive over ageing characteristics of bituminous mixtures have been investigated. In order to estimate the proportion of hardening of warm mix asphalt specimens containing different contents of organic additive and control specimens with no additive content, all specimens have been subjected to short- and long-term ageing. Afterwards, ageing indices have been calculated considering the ratio of indirect tensile strength values of both short- and long-term aged specimens over un-aged specimens. The results show that the aging indices of specimens containing organic warm mix asphalt additive are rather less than the indices of hot mix asphalt specimens.