Characterization of bakelite-modified bitumen

This study investigated the influence of Bakelite on the physical, performance, and mechanical properties of bitumen binder. Bakelite is the trade name of phenol formaldehyde—a thermosetting type of plastic. It is a polymer amorphous in nature having three-dimensional structure. This imparts hardness, strength, and rigidity. Bakelite was blended in the bitumen in variegated percentages from 1 to 5% with an increment of 1%. The blended bitumen was characterized by penetration, softening point, and dynamic viscosity using rotational viscometer and compared with unmodified bitumen of penetration grade 60/70. The rheological parameters were investigated using Dynamic Shear Rheometer (DSR) (AASHTO Provisional Standards: AASHTO T315-08, Standard test method for determining the Rheological properties of asphalt binder using a Dynamic Shear Rheometer (DSR) Washington, 2011), and mechanical properties were investigated using Marshall stability test. The results indicated an increase in softening point, dynamic viscosity, and decrease in binder penetration up to 2% modifier content and then follow the reverse trend. The blending of bitumen with bakelite increased complex modulus, decreased phase angle, and improved rutting resistance as well. There was a significant improvement in Marshall stability, rather a marginal improvement in flow value. The best improvement in the modified binder was obtained with 2% bakelite. This project demonstrates that the properties of bitumen can be improved by adding Bakelite in it. With negligible raise in initial cost of the construction, the life and performance of pavements can be increased for a long duration.