Study of the lixiviation behavior of mortars produced with recycled aggregates

Abstract

Construction and demolition waste is constituted, in great part, by construction materials; however, it may contain dangerous substances, such as heavy metals. In order to reduce the CDW volume to be disposed in landfills, there is a certain tendency to manufacture it as recycled aggregates to be used in materials. Thus, it is indispensable to investigate the recycled aggregates verifying the possible risk of environmental contamination and the contaminants interference in its characteristics. In this study, mortars were produced using fractioned recycled aggregates. The mortars were cured for 28 days and then taken to tank test, according to NEN 7345. The results show that heavy metals are leached from mortars produced with recycled aggregates in high concentrations. In the period of 24h, the concentrations obtained were lower than the recommended limits by NBR 10004 (2004), but much higher than the limits defined by the European