Bitumen, also known as asphalt, is a gluey, black liquid or semi-solid material with considerably high viscosity. The primary utilization of bitumen is in road paving, where it is used as the binder mixed with sand, gravel and aggregate particles to produce road paving or coating concrete. Generally, bitumen is used became of its two distinct properties, i.e. adhesion and waterproofing. Bitumen is also used as bitumen water proofing material for sealing roofs and floors. The direct use of bitumen in its native form in road construction is not suitable, became it would lead into relatively rapid destruction and deformation of pavement due to heavy road motor vehicle traffic and temperature change over time. Hence, modification of bitumen for better performance properties attracted much attention in recent decades. Modification of bitumen properties can be performed by chemical and/or physical pretreatment. Use of polymers is nowadays a matter of common practice and use of used tire-rubber pyrolysis products has been reported in recent years. In this research project, pulverized truck-used tire was subject to pyrolysis, and the by products along with poly phosphoric acid was blended with a local refinery bitumen (type 85/100), and the properties of the final compound were evaluated. A pyrolysis reactor setup was designed, constructed and used for pyrolysis experiments. In each batch, 150 g of used tire powder (NR) was used and the final product distributions were analyzed. In pyrolysis experiments, effects of addition of such heavy solid paraffin and sodium hydroxide were studied. Results of pyrolysis indicate that the addition 5, 10, and 15 g of sodium hydroxide increase the pyrolysis residue from 33% (no additive) to 43% (15 g sodium hydroxide). On the other hand, addition of 1 g solid paraffin increased the pyrolysis oil from 37.5% to 42%, and addition of both additives leads to decreased pyrolysis oil, decreased residue and increased gas products. Pyrolysis oil products were subject to solvent extraction tests using acetone. Results show that when 1 g of solid paraffin is used the dissolution of pyrolysis oil in acetone is decreased from 64.7% to 51.3% and that the reduction of dissolution in acetone is inversely proportional to the amount of the solid paraffin used. Finally, addition of 3 wt% of pyrolysis oil to 85/100 bitumen results into increased penetration from 90 dmm to 119.5 dmm,and the softening point is increased from 46.1°C to 40.3 °C. Further, addition of 0.5 wt% solid nano-particles of the pyrolysis residue and 1.5 wt% PPA the penetration is decreased from 90 dmm to 41.5 dmm and softening point is increased from 46.1?C to 67.2?C and ductility is decreased from over 100 cm to 8.5 cm. Keywords: Bitumen; elastic powder; hydroxide sodium, solid paraffin; pyrolysis; p olyphosphoric acid; modification