title: Use of weathered and fresh bottom ash mix layers as a subbase in road constructions: environmental behavior enhancement by means of a retaining barrier.
abstract: The presence of neoformed cement-like phases during the weathering of non-stabilized freshly quenched bottom ash favors the development of a bound pavement material with improved mechanical properties. Use of weathered and freshly quenched bottom ash mix layers placed one over the other allowed the retention of leached heavy metals and metalloids by means of a reactive percolation barrier. The addition of 50% of weathered bottom ash to the total subbase content diminished the release of toxic species to below environmental regulatory limits. The mechanisms of retention and the different processes and factors responsible of leaching strongly depended on the contaminant under concern as well as on the chemical and physical factors. Thus, the immediate reuse of freshly quenched bottom ash as a subbase material in road constructions is possible, as both the mechanical properties and long-term leachability are enhanced.
authors.affiliation: Departament de Ciència dels Materials i Enginyeria Metal·lúrgica, Universitat de Barcelona (UB), Martí i Franqués, 1, 08028 Barcelona, Spain.
authors.forename: R
authors.initials: R
authors.lastname: Del Valle-Zermeño
authors.affiliation: Departament de Ciència dels Materials i Enginyeria Metal·lúrgica, Universitat de Barcelona (UB), Martí i Franqués, 1, 08028 Barcelona, Spain. Electronic address: chimenos@ub.edu.
authors.forename: J M
authors.initials: JM
authors.lastname: Chimenos
authors.affiliation: Departament de Ciència dels Materials i Enginyeria Metal·lúrgica, Universitat de Barcelona (UB), Martí i Franqués, 1, 08028 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Giró-Paloma
authors.affiliation: Departament de Ciència dels Materials i Enginyeria Metal·lúrgica, Universitat de Barcelona (UB), Martí i Franqués, 1, 08028 Barcelona, Spain; Departament Construccions Arquitectòniques II, Universitat Politècnica de Catalunya (UPC), Av. Dr. Marañón 44, 08028 Barcelona, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Formosa
mesh_terms: D060729:Coal Ash / Q000737:chemistry*; D003252:Construction Materials / Q000032:analysis*; D004784:Environmental Monitoring; D055595:Mechanical Phenomena; D019216:Metals, Heavy / Q000032:analysis*; D012037:Refuse Disposal; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D060729:Coal Ash; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
keywords: Freshly bottom ash; Heavy metal retention; Retaining barrier; Road construction; Weathered bottom ash