Analysis concept for the determination of trace elements in the eluate of cement-bound building materials (IGF No. 16989 N)

The significance of environmental compatibility in construction products has increased considerably over recent years. In terms of ground water and soil, evidence of environmental compatibility is provided in the form of leaching tests, e.g. as part of the long-term tank test, which determines the release of trace elements from building materials. As the very low insignificance threshold values of the Länderarbeitsgemeinschaft Wasser (Inter-state Working Group for Water, LAWA) are used as the basis for assessment, a reliable, reproducible trace element analysis system is extremely important.

Numerous investigations have proven that only very low quantities of trace elements leach out of cement-bound building materials. These low concentrations may lead to greater scattering in the analysis. The aim of the AiF research project was to identify the causes of the sometimes greater scatter rates in the analysis results in the case of comparison trials for the long-term tank test. Measures should be developed in order to improve reproducibility and comparability of the results. Another aim of the project was to record the possible influence of after-treatment of the test pieces on the leaching behaviour of trace elements from concrete using systematic investigations. The project was carried out in collaboration with the Institut für Bauforschung (Institute for Building Research, ibac) in Aachen.