Leaching behaviour of renderings and mortars

In this paper the results of two research projects concerning the leaching behaviour of renderings and mortars are presented. At the Institute of Building Materials Research of the RWTH Aachen University two renderings and a masonry mortar were leached in irrigation tests and long term tank tests. The results are compared to the results of outdoor experiments, which have been carried out by the Fraunhofer Institute for Building Physics of Holzkirchen. The results show that one type of experiment does not generally show the highest release rates. For some elements wet and dry cycles seem to have influence on the leaching behaviour. The comparison of the concentrations and the limit values for groundwater showed that most trace elements are not critical. But chromium and vanadium shall be further investigated.