Studies on warm stone asphalt mixes using natural and synthetic fibres

Abstract

Studies were carried on conventional stone matrix asphalt (SMA) mix, Warm SMA mix and RAP Warm SMA mix using natural and synthetic fibres as stabilizers.PMB40 and zycotherm are used as a binder and warm mix additive respectively.RAP Warm SMA mixes was prepared by adding 30% RAP content using WMA. Marshall method of mix design was adopted and mixes properties were determined at lower working temperature by mixing at 130 °C,120 °C and compacting at 120,110, 100, 90 °C to check the influence of these temperatures on asphalt mix properties. The optimum binder content was determined for above combinations. The mixes were tested for moisture susceptibility, fatigue life and rutting resistance.It is observed that RAP Warm SMA prepared using Synthetic fibre exhibited increased stability at 130 °C mixing and 120 °C compaction temperature. Similarly RAP Warm SMA prepared using Sugar cane fibre showed higher Tensile strength (TSR) value at 130 °C mixing and 120 °C compaction temperature. It was observed that fatigue life and rutting resistance decreased with reduction in compaction temperature from 130 °C to 110 °C and 100 °C. The optimum mixing and compaction temperature was found to be 1300 and 120 °C respectively for sugar cane and synthetic fibres to exhibit better fatigue and rutting resistance.