The use of reclaimed asphalt pavement (RAP) in manufacturing asphalt concrete has
become indispensable all over the world. This is due to the limited number of areas that are
required to stockpile scraped pavement, as well as a lack of natural aggregate, which is necessary in
manufacturing asphalt concrete. Thus, this research aims to evaluate the mechanical characteristics
and environmental impact of using RAP and waste polyethylene in hot mix asphalt (HMA). RAP
was added to hot mix asphalt in proportions of 25%, 50%, 75%, and 100% instead of the same amount
of coarse aggregate. Then, the optimum RAP hot mix asphalt was modified by adding polyethylene
in proportions of 1%, 2%, 3%, and 4% into the hot mix asphalt. The Marshall mix design was
used to define the optimum asphalt content. As a final point in this experimental work, tests on
the loss of stability, indirect tensile strength, and wheel loading tracking were performed to assess
the performance of asphalt mixes modified with RAP and polyethylene in different conditions. A
life cycle assessment (LCA) was applied using the ReCipe 2016 Endpoint method to evaluate the
environmental impacts of these mixtures using the SimaPro software, V9.1. The laboratory tests
showed that the mixture containing 50% RAP instead of the same amount of coarse aggregate and
2% polyethylene recorded better Marshall characteristics than the control mixture and the mixture
with RAP alone. Finally, the modified hot mix asphalt with added RAP and polyethylene not only
achieved superior performance in rutting, water damage resistance, and the stiffness modulus of
bituminous mixtures, but it has been verified that there is no serious risk to the environment. |
