title: Leaching of hazardous substances from a composite construction product--an experimental and modelling approach for fibre-cement sheets.
abstract: The leaching behaviour of a commercial fibre-cement sheet (FCS) product has been investigated. A static pH dependency test and a dynamic surface leaching test have been performed at lab scale. These tests allowed the development of a chemical-transport model capable to predict the release of major and trace elements over the entire pH range, in function of time. FCS exhibits a cement-type leaching behaviour with respect to the mineral species. Potentially hazardous species are released in significant quantities when compared to their total content. These are mainly heavy metals commonly encountered in cement matrixes and boron (probably added as biocide). Organic compounds considered as global dissolved carbon are released in significant concentrations, originating probably from the partial degradation of the organic fibres. The pesticide terbutryn (probably added during the preservative treatment of the organic fibres) was systematically identified in the leachates. The simulation of an upscaled runoff scenario allowed the evaluation of the cumulative release over long periods and the distribution of the released quantities in time, in function of the local exposure conditions. After 10 years of exposure the release reaches significant fractions of the species' total content - going from 4% for Cu to near 100% for B.
authors.affiliation: University of Toulouse; INSA, UPS, INP; LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR 792, F-31400 Toulouse, France; CNRS, UMR 5504, F-31400 Toulouse, France; Paris-Est University; CSTB-Scientific and Technical Centre for the Building Industry, DEE/Environmentand Life Cycle Engineering Team, 24 rue Joseph Fourier, F-38400 Saint Martin d'Hères, France.
authors.forename: Maria
authors.initials: M
authors.lastname: Lupsea
authors.affiliation: University of Toulouse; INSA, UPS, INP; LISBP, 135 Avenue de Rangueil, F-31077 Toulouse, France; INRA, UMR 792, F-31400 Toulouse, France; CNRS, UMR 5504, F-31400 Toulouse, France. Electronic address: ligia.barna@insa-toulouse.fr.
authors.forename: Ligia
authors.initials: L
authors.lastname: Tiruta-Barna
authors.affiliation: Paris-Est University; CSTB-Scientific and Technical Centre for the Building Industry, DEE/Environmentand Life Cycle Engineering Team, 24 rue Joseph Fourier, F-38400 Saint Martin d'Hères, France.
authors.forename: Nicoleta
authors.initials: N
authors.lastname: Schiopu
mesh_terms: D003252:Construction Materials / Q000032:analysis*; D015386:Hazardous Substances / Q000032:analysis*; D008956:Models, Chemical
chemical_list: D015386:Hazardous Substances
keywords: Chemical-transport model; Environmental assessment; Fibre-cement sheets; Leaching tests; Long-term leaching