EFFECT OF LDPE/CR ADMIXTURE ON THE PROPERTIES OF BITUMINOUS BINDER USED IN PAVING APPLICATIONS

A plastic-elastomer admixture was prepared by blending the recycled low density polyethylene (LDPE) and crumb rubber (CR) recycled from wasted tyres in the presence of tall oil. They are blended in two ratios 1:2 and 1:3, LDPE/CR respectively. In this study two wasted materials, LDPE and CR were taken to improve the properties of base bitumen binder. The CR in the form of powder having particle size less than 0.7 mm, was used blended with melted bitumen at 160-1700C with the help of high speed shear mixer for 1 hour. In the same manner the different compositions were made 3, 5, 8 and 12 percent by weight of LDPE, CR and LDPE/CR combination in both ratios 1:2 & 1:3. These modified blends are characterized in terms of penetration, softening point and viscosity, which found better as compared to base bitumen. The most suitable results are obtained when LDPE, CR and LDPE/CR were used below 8% by weight. The elastic recovery test of 8% by weight of LDPE/CR in the ratio 1:3 meets the requirement of specification and this composition is best suited to be for road constructions.