Characteristics of artificial coarse aggregate from High Density Polyethylene (HDPE) plastic waste for highway flexible pavement

Aggregates are a major component of hot mix asphalt and make up about 85% of the total mix volume. The increasing expansion of road infrastructure in Indonesia has led to a depletion of aggregate resources. Conversely, Indonesia is one of the largest producers of plastic waste in Southeast Asia. The aim of this study is to evaluate the potential of high density plastics (HDPE) for use as artificial aggregate material in flexible road pavements. The parameters investigated include softening and melting point, penetration and elongation index, gradation value, specific gravity, absorption and abrasion of the aggregates. The investigations into the physical properties of the artificial aggregates revealed a softening point of 265°C and a melting point of 272°C. The penetration index was 0.77% and the elongation index was 0.70%. The classification values passing through the 3/4" sieve were 100%, 66.88% for the 1/2" sieve and 25.96% for the 3/8" sieve. The specific gravity of the artificial coarse aggregate was 1.629. The absorption of the artificial coarse aggregate was 1.270% and the abrasion value was 0.15%. In summary, the artificial coarse aggregates produced from HDPE plastic waste can serve as a partial substitute for natural coarse aggregates.