Laboratory Study on a Warm Bituminous Mixx

Abstract

About 80%of road network in India comprises of flexible pavement in which Hot Mix Asphalt (HMA) is used in the bituminous layer. Warm Mix Asphalt (WMA) is helpful in certain situations when the problems associated with HMA may be reduced. Warm mix asphalt lowers the mixing emperatures at which asphalt pavement materials are mixed and laid on road. The advantages of WMA are reduced emissions, improved workability and reduced energy consumption. In addition, it provides easier compaction in longer haul distances and extreme weather conditions. In this study, an experimental investigation has been carried out involving a warm mix chemical additive which can be easily available.To decide the optimal concentration of additive for DBM mix, Warm Mix has been prepared by using additive with VG 30 at varying mixing temperatures of 110°C, 120°C, 130°C and 140°C. As per the specifications of MORTH, Marshall samples are prepared using dense bituminous macadam (DBM) grading and afterward Marshall properties were studied with optimum mixing temperature and optimum binder additive composition. It was observed thatthe DBM warm mix with additive provided higher indirect tensile strength (ITS) and higherMarshall stability with other reasonable satisfactory Marshall parameters. The retained stability and tensile strength ratio are also found to be reasonably satisfactory in such warm mixes. The resulting warm mixes are also observed to be quite comparable to the Control HMA.