Environmental Impact Assessment of the Concrete Composites in Terms of the Selected Toxic Metals Leaching

Abstract

The concrete materials have to fulfill a lot of technical criteria before being built and used in the building structures depending on their application. In general, concrete is considered to be very stable and harmless material. However, due to various atmospheric influences on concrete materials, such as acid rain, as well as due to massive utilization of wastes in concrete production in various forms, concrete materials testing for the toxic metals leaching is of great importance at present. The paper presents the results of the various concrete composites leaching analyses in various liquid media (distilled water, rain water and Britton-Robinson buffer). The exposition to the model liquid environment proceeded over a period of 30 to 240 days. The leachability and toxicity of heavy metals depends on a number of factors even some elements may have very different toxic profiles depending on their chemical form. Hexavalent chromium and barium have been selected to be analysed representing the most leachable metals in cements. The Cr (VI) and Ba ions concentrations leached have been measured using colorimetric analysis. The additional parameters such as pH and conductivity have been also investigated.