Abstract:
During the last decade, the rehabilitation and improvements of road networks in Sri Lanka exhibited a
rapid development. As a result many of roads were undergone for new asphalt surfacing with hot mix asphalt, at
least a wearing course, and the black top. However, with this rapid development, few premature failures were also
observed in many of these newly constructed asphalt roads covering all part of Sri Lanka. Pre-mature cracking,
removal of top thin film of wearing layer, bleeding and localized failures were among them. Bitumen played a very
important role in hot mix asphalt and improvement for bitumen can enhanced the improved properties of HMA
significantly. In this research, instead neat 60/70 grade of bitumen, it was used modified 60/70 grade, with Nano
silane, enhancing anti-stripping and bonding capabilities. Research was comprised three stages of testing, lab trials,
plant trials and filed trial in Colombo- Kandy road section. Results showed significant improvement for marshal
properties. The stability and flow increased by 24% and 35 %, respectively. The anti-stripping property was also
increased significantly, even after 6 hr, boiling test, it showed elevated no of coated aggregates. In addition, the mix
was very well after few weeks, and very sticky condition proved that the strong bonding ability. All enhanced
characteristics can be caused to exhibit improved performance and can be lead to extended life period of road
construction.
