Properties of Solid Waste Incinerator Fly Ash

Abstract

Since the late 1950s solid waste incinerators have become widely used in the United States. The incineration of solid waste produces large quantities of bottom and fly ash, which has been disposed of primarily by landfilling. However, as landfills become undesirable other disposal methods are being sought. An experimental research program is conducted to determine engineering properties of solid waste incinerator fly ash (SWIF) in order to evaluate the feasibility of using the material for compacted fill and road and subbase construction. Moisture‐density relationship, permeability, shear strength, and California bearing ratio (CBR) are investigated. The effects of densification on these engineering properties are also examined. In addition, the effectiveness of cement and lime stabilization is investigated using two common mix ratios. Test results of stabilized mixes are compared to the unstabilized material. Cement stabilization is found to be very effective in reducing permeability, and increasing shear strength and CBR values of the material. The results indicate that SWIF with cement stabilization may be used effectively for compacted fill and road subbase construction. Finally, some environmental aspects related to these applications are examined.