Microstructural study of carbonated cement-solidified synthetic heavy metal waste

Synthetic wastes have been widely employed to help elucidate the complex in teractions between real wastes and hydraulic binders during solidification. In this work, a laboratory produced metal waste mixed with Portland cement and immediately carbonated it using an accelerated method. The microstruct ures of carbonated and non-carbonated control samples were distinct despite both being dominated by unusually large phenograins derived from the waste . In the carbonated sample waste phenograins remained unaltered, whereas ce ment grains were largely decalcified. As a consequence of decalcification, observable porosity was significantly reduced by the formation of precipita ted carbonates. (C) 1999 Elsevier Science Ltd. All rights reserved.