Effects of warm mix asphalt additives on aging characteristics of bituminous mixtures

Abstract

In recent decades, the utilization of the warm mix technologies in pavement constructions is increasing rapidly with rise in public environmental awareness. The durability of a pavement highly depend on the behavior of the pavement against aging induced failures. Therefore this study encompasses the evaluation of short- and long-term aging characteristics of four kinds of Warm Mix Asphalt (WMA) additives. Additives distinctly assessed in this study, consist of two non-foaming (organic and chemical) and two foaming(synthetic and natural zeolite) additives. In order to appraise the proportion of hardening of mixtures containing different kinds of additives, indirect tensile strength (ITS) values of both short- and long-term aged specimens were determined. Based on relative aging indices derived from the ratio of ITS values of aged and unaged specimens, comparisons were made between the additives assessing the impact of their utilization on aging characteristics of WMA.