MIX DESIGN PROPERTIES AND MOISTURE SENSITIVITY CHARACTERISTICS OF DENSE BITUMINOUS MACADAM MIXES MODIFIED WITH REDISET, A WARM MIX ADDITIVE

Arun S Bagi, Vijay Gomarshi, Shivaraj B S

Abstract: Warm mix asphalt is a developing technology which allows the mixing, lay down and compaction of asphalt mixes at lower temperatures. Warm mix asphalt mixes can be produced at temperature about 120º C or lower which helps in saving the fuels and proves Eco friendly. A number of researchers evaluated various WMA mixtures using selected testing procedure in the laboratory. But only few of them varied both the temperature and additive dosage rate. In this study, the main objective is to study the effect of WMA additive Rediset on the viscosity of bitumen at different temperatures and to evaluate the properties like Marshal Stability, Indirect Tensile Strength and Moisture Susceptibility of DBM mix along with the warm mix additive. The binder showed a decreasing trend in viscosity with increase in the temperature as well as additive dosage rate. The DBM mix with 2.5% WMA additive exhibits higher stability values even at 135° C or lower the temperatures. The specimens with additive showed the lowest value of air voids which were within the limit of 3-6%, which indicate WMA additives are effective in compacting mixtures at 120° C or lower. Indirect Tensile Strength and Tensile Strength Ratio values of the mixtures with WMA additive were found to be higher than the mixtures without additive Rediset. Based on the overall test results it can be concluded that WMA additive Rediset is effective in producing the mixtures with high strength at mixing temperatures of 135° C and 115° C.

Keywords: WMA, DBM, Additive

DOI: https://doi.org/10.15623/ijret.2014.0307027