EVALUATION OF DOMESTIC INCINERATOR ASH FOR USE AS AGGREGATE IN ASPHALT CONCRETE

The potential use of incinerator ash in asphalt concrete paving was evaluated. Laboratory tests were conducted on ash from a waste-to-energy incinerator. Tests were conducted to assess whether asphalt concrete mix with ash was suitable both in terms of physical performance and environmental safety. It was determined that a mix with acceptable parameters on the Marshall tests could be produced with an aggregate consisting of up to 32% incinerator ash. This mix requires a higher asphalt content than a normal mix and appears to be prone to stripping. The results of the toxicity tests on the leachate were inconclusive; however, they suggest that there might be a problem since a significant amount of lead was detected in the leachate. It was concluded that an asphalt concrete mix with ash might be suitable for use in base course or for low-quality surface applications. However, a significant quantity of undesirable material must first be removed to get an aggregate of acceptable quality. Only about one-third of the material in the bottom ash is suitable for use in an asphalt concrete mix.