Long-term leaching of toxic trace metals from Portland cement concrete

Over the past 30 years, environmental regulations in the United Kingdom have become increasingly stringent. Concerns recently were aired over cementitious materials coming into contact with water for human consumption. Some of these materials, by virtue of their origin, can contain toxic trace metals in their composition. Results of a study investigating the long-term leaching of toxic trace metals from various Portland cement mortars in an aqueous environment are presented. Test samples were subjected to a leaching procedure based on criteria detailed by the Netherlands "diffusion" method. The leachates generated were analysed for various toxic metals outlined in directive 80/778/EEC using atomic absorption spectroscopy. The analytical results revealed only vanadium leached in detectable quantities from poorly cured concrete, and its removal was restricted from the surface only. (C) 1999 Elsevier Science Ltd. All rights reserved.