Bitumen Modification with Polysulphide Polymer Prepared from Heavy End Waste

Heavy end waste is produced as a by-product in purification unit of vinyl chloridemonomer in petrochemical complexes. This waste should be recycled or reusedwith ensured safety. Preparation of polysulphide polymer from this waste is oneof the solutions to reuse this waste. This paper deals with the effects ofpolysulphide polymer (PSP) and waste residue from distillation of heavy ends waste(WR) on the morphology, engineering and rheological properties of bitumen. To achievethis goal, polysulphide polymer was prepared from the distillated heavy ends wastewhich consists of a mixture of various chlorinated organic hydrocarbons and alkalipolysulphide. Subsequently, bituminous blends were produced by mixing 60/70penetration grade bitumen and 1, 3 and 5 wt% of PSP or WR. An optical microscopywas employed to study the morphology of samples. The observed morphology wasattributed to physical interactions acting between the phases. The engineeringproperties of modified bitumen containing PSP and WR were also determined andcompared with those of blank bitumen. The experimental results showed that softeningpoint of the bitumen increased whereas its penetration decreased upon incorporationof PSP. In the case of WR, a reverse effect was observed. The experimental mastercurves of G and G obtained from the oscillatory rheological measurements usingtime-temperature superposition principle were reported. The shift factors used inconstructing master curves indicated an Arrhenius type temperature dependency. Thecalculated flow activation energy of the bituminous blends showed higher resistanceagainst their flow. It confirmed less rutting at high temperatures in comparison with thatof the base bitumen.