MECHANICAL AND LEACHING PROPERTIES OF CEMENT SOLIDIFIED HOSPITAL SOLID-WASTE INCINERATOR FLY-ASH

A By ash coming from a hospital solid wastes incineration plant was so lidified/stabilized in cementitious matrices. Owing to the high chlori de, sulphate and alkali content and the low Si, Al and Fe values this By ash cannot be used in the formulation of blended cement. The object ives of solidification stabilization treatment were therefore to reduc e the leachability of the heavy metals present in this material so as to permit its disposal in a sanitary landfill requiring only a low deg ree of environmental protection. The mechanical properties and leachin g behaviour of solidified products were investigated. Fly ash and Port land Cement mixtures in ratios varying between 0.25 and 1.5 were teste d for unconfined compressive strength after curing in tap water at 20 degrees C. Leaching tests were performed both on By ash and solidified /stabilized products using an acetic acid standard leaching test and a modified version thereof (dynamic leaching test). (C) 1998 Elsevier S cience Ltd. All rights reserved.