Properties of asphaltic concrete mixed with marine debris

Abstract

Increasing amounts of marine debris including plastic bottles and glass cullet waste are negatively impacting coastal ecosystems. Applying asphalt concrete can reduce marine debris. Aggregate materials in the asphalt concrete job mix formula were combined with plastic flakes (P) and glass cullet (G) of sub-size less than 0.30 mm and retained on a #50 sieve. Mixing ratios at P25:G25, P25:G50, P50:G25 and P50:G50 were employed. The aggregate material was mixed in a hot bin at the mixing ratios of 40:33:15:12 by weight using asphalt cement grade AC 60-70 mixed with ratios 4.5, 5.0, 5.5, 6.0 and 6.5 by weight of the mass aggregate in a laboratory. Laboratory engineering properties of the asphalt concrete specimens were tested following the Marshall method by the Department of Highways (DOH). Replacement of 25% plastic flakes and 25% glass cullet (P25:G25) improved density, stability, flow, percentage of air voids (%AV), voids filled with asphalt (%VFA) and voids in mineral aggregate (%VMA) as optimal ratios of DOH standard testing requirements, followed by mixing ratio P25:G50. Mixing ratio P25:G25 showed promise as an alternative to reduce marine waste.