Polypropylene Modified Asphalt Mix to Improve Wearing Course of Flexible Pavement

摘要

Increasing traffic volume in Bangladesh demands a corresponding increment in the load-bearing capacities of the pavement. Bitumen modification could be an effective solution to minimize premature failure like rutting, cracking, potholes, etc. This research aims to investigate the effect of polypropylene on the physical properties of asphalt and asphalt mixes. Percentages of polypropylene used for the modification are 1%, 2%, and 3%. A series of laboratory tests were conducted to find the physical properties of the modified asphalt and mixes. It is found that the incorporation of polypropylene decreases the penetration by 19% and ductility by 40% of neat bitumen. However, it is found that the softening point of the bitumen slightly increases by 3% of neat bitumen. Though, a 21% increase in stability value is observed if asphalt is modified with 3% polypropylene. It can be concluded that polypropylene modified bituminous mixes may mitigate the premature failure problem of HMA pavement to some extent by increasing stability and softening point.