Use of Municipal Solid Waste Incinerator Bottom Ash as Coarse Aggregate in Concrete

The leaching of municipal solid waste incinerator (MSWI) bottom ash has been studied at different stages of natural weathering. Bottom ash samples, originating from a single incinerator, included grate siftings, unquenched, quenched, 6-week-old & 12-year-old bottom ash. The particles with diameter > 1mm present in the bottom ash of MSWI were characterized by identifying the main constituent materials. This characterization may be used to evaluate the potential applications of bottom ash & its environmental hazards, & to evaluate the possibilities of recycling its main components. The effectiveness of the voluntary recycling programs of bottom ash can also be assessed. The main components of the bottom ash are glass, magnetic metals, minerals, synthetic ceramics, paramagnetic metals & unburned organic matter. The 4-25mm size fraction accounts for approximately 50% of the bottom ash weight & comprises mainly glass (>50% of this fraction), synthetic ceramics (26%) & minerals (>8%), & thus appears to be suitable for reuse as secondary building materials or for glass recycling. Magnetic metals accumulate in the 1-6mm particle size fraction (6% of this fraction).