Environmental impacts of steel slag reused in construction

Abstract

The paper presents an overview on regulations and standards related to environmental issues when using steel slag as construction materials and backfill materials. Accordingly, steel slag samples were determined hazardous compositions, natural radioactive properties, and total concentrations of potentially leachable heavy metals within the laboratory research. The results show that steel slags can be classified as non-hazardous waste in accordance with QCVN 07:2009/BTNMT – National technical regulation on hazardous waste thresholds. Furthermore, the radioactivity index of the steel slag samples used in the study also completely met the requirements specified in both Vietnamese standard named “TCXDVN 397:2007-Natural radioactivity of building materials- Safety level in use” and test methods and Finland standard named “STUK ST 12.2/2010-The Radioactivity of Building materials and ash”. Although heavy metals were found in steel slags, the low leaching ability of these metals was confirmed in practical uses. In order to give out a comprehensive conclusion on the environmental impacts of steel slag utilization, further environmental tests under actual conditions need to be performed. However, this initial results of laboratory research have demonstrated that steel slags have a great potential use as construction materials and backfill applications without the risk of environment surrounding the area of use.