Characterization of Penetration Grade Bitumen Blended with Petroleum Products for Cutback Production

Cutback bitumen is a potential binder that can be used for producing cold mix asphalt. This study presents the characteristic of produced cutback bitumen according to different types of diluent used. The 60/70 penetration grade bitumen was mixed with different petroleum solvents (gasoline, kerosene, and diesel) to produce cutback bitumen for potential usage in asphalt pavement. The binder’s viscosity and evaporation rate (curing time of solvent) were investigated to select the appropriate percentage of solvent that provides lower mixing and compacting temperature range. The percentage of diluent was varied at 30, 35, 40, and 45%. The viscosity was measured at a temperature ranging from 30 to 70 °C with an increment of 10 °C, while the evaporation rate was measured at an ambient temperature. The results show that the viscosity of each blended bitumen decreases as the percentage of diluent in the mix increases. The evaporation rate of the solvent is higher for gasoline and kerosene than diesel due to the volatility and chemical compositions of the solvents. From the data obtained, the most effective percentage of solvent for the cutback production is 40–45% by weight of the penetration grade bitumen, which establishes the lowest potential mixing and compacting temperature range for the asphalt.