Leaching of PCE-based Superplasticiser from Microfine Cement: a Chemical and Ecotoxicological Point of View

The construction materials industry faces major challenges since 2013 when the European Construction Products Regulation was implemented, especially in the sector of environmentally friendly construction products. This study determined concentrations of leachable inorganic and organic compounds from microfine cement paste with and without superplasticiser addition. Furthermore, the leached superplasticiser amounts were detected via LC-MS. The multi-method approach was supplemented by ecotoxicological assays. Phytotoxicity was tested with white mustard (Sinapis alba) and cress (Lepidium sativum). The mutagenic and genotoxic potential of the leachates was tested with the Ames fluctuation assay and the umuC assay. As leaching protocol, the European horizontal dynamic surface leaching test was used. The cement paste samples with superplasticiser followed the wash-off effect with a total organic carbon release up to 43 mmol/m², whereas the release of samples without superplasticiser was driven by diffusion. The ecotoxicological assays showed a clear time depending behaviour. No cytotoxicity and mutagenicity could be observed; anyhow some leachates show minor genotoxic potential. In all tests, a clear difference between the samples with and without superplasticiser could be detected.This study clearly demonstrates the importance of further studies in the field of leaching of construction products.