NEWLY DEVELOPED CRUMB RUBBER MODIFIED (CRI1) ASPHALT MIXTURES

Scrap tire usage in road construction started many years ago and modification of bitumen with crumb rubber in road paving applications has been growing rapidly over the last four decades. This paper examines the properties of base bitumen and crumb rubber modified with antioxidant (CRI1) using a Dynamic Shear Rheometer (DSR). The rheological properties of CRI1 and PMA-D modified bitumen are compared with unmodified 80/100 bitumen. Subsequently, these mixtures are compacted by the gyratory compactor and conditioned for short and long term ageing in accordance with the procedure outlined in AASHTO R30-02. The mixtures are then evaluated for stiffness modulus under standard conditions so as to judge the extent of ageing through the increase in stiffness. This approach enables the establishment of a relationship between comple