ENVIRONMENTAL COMPATIBILITY OF BUILDING MATERIALS IN CONTACT TO GROUNDWATER

摘要

This paper focuses on the evaluation of the environmental compatibility of concrete, which is used in contact with groundwater. The German regulations for hardened concrete that are used for technical approvals of new raw materials for concrete are explained. The leaching of fresh concrete was investigated in a field test and in laboratory tests. Based on the laboratory tests the groundwater concentrations were calculated using a numerical transport simulation program. A comparison of the real concentration and the calculated values showed that transport modelling is an adequate tool for the evaluation of the leaching of building materials. An evaluation concept should always include a realistic description of the source term, which is usually time-dependent, reasonable assumptions for the transport (e.g. adsorption or decay of organic compounds) and a practice-relevant exposure scenario, for which the concentrations in soil or groundwater are modelled. These concentrations can be compared to national limit values.