Abstract:
The growth in varies type of industries together with population growth has resulted in enormous
increase in production of varies type of waste plastic material and it is one of the major
environmental concerns. On the other side, the road traffic and the traffic intensity is increasing;
the load bearing capacities of the road should be improved. To deal with the problem, study on
use of plastic waste as partial replacement to bitumen is considered in the present work. This
paper will help to take care of both those aspects.
The main objective of this study was to evaluate laboratory performance of modified bitumen mix
using waste plastic for flexible pavement to enhance asphalt mix properties. This research has
determine the best method of adding polymer in asphalt mix. In this study four proportion (6,9,12
&15%) of waste plastic ( PET and HDPE) were introduced in the asphalt mixture with a selected
aggregate grading. Marshal mix design procedure was used, first to determine the Optimum
Bitumen Content (OBC) and the OBC was 5.1% by weight of asphalt mix. Number of laboratory
tests such as penetration, ductility, softening point, loss on heat and marshal stability test has
been carried out by replacing some parts of the bitumen with plastic waste. The results show that
there is an improvement on those properties when compared to normal bitumen.
The Marshal stability results reveals that the waste plastic (PET and HDPE) increases the
stability values of the compacted mixes with increasing the waste plastic content in the bitumen up
to 9% PET and 12% HDPE. The density of the compacted mixes slightly decreases with the
increase of waste plastic contents in the bitumen.
It is expected that using the output of this research, provide an economical solution and minimize
the frequency of rehabilitation work by improving the performance of asphalt. It is also expected
to substantially reduce volume of environmentally hazardous plastic and environmental pollution.
Study recommends contractors and local authorities to confirm using waste plastic in asphalt mix
with the proposed percentage (7% PET and 8% HDPE by OBC weight) to improved the
performance of asphalt mix. Moreover, further studies are needed in various topics related to
effective utilization and best incorporation techniques of waste materials.
