title: Size-dependent enrichment of waste slag aggregate fragments abraded from asphalt concrete.
abstract: Authors consider the environmental prospects of using melted waste slag as the aggregate for asphalt pavement. In particular, the enrichment of slag-derived fragments in fine abrasion dust particles originated from slag asphalt concrete and its size dependency were concerned. A series of surface abrasion tests for asphalt concrete specimens, containing only natural aggregates as reference or 30 wt% of substituted slag aggregates, were performed. Although two of three slag-asphalt concretes generated 1.5-3.0 times larger amount of abrasion dust than the reference asphalt concrete did, it could not be explained only by abrasion resistance of slag. The enrichment of slag-derived fragments in abrasion dust, estimated on the basis of the peak intensity of quartz and heavy metal concentrations, had size dependency for all slag-asphalt concretes. Slag-derived fragments were enriched in abrasion dust particles with diameters of 150-1000 μm. Enrichment factors were 1.4-2.1. In contrast, there was no enrichment in abrasion dust particles with diameter less than 75 μm. This suggests that prior airborne-size fragmentation of substituted slag aggregates does not need to be considered for tested slag aggregates when environmental risks of abrasion dust of slag-asphalt pavement are assessed.
authors.affiliation: Faculty of Urban and Environmental Engineering, Graduate School of Engineering, Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan. f-takahashi@doc.kyushu-u.ac.jp
authors.forename: Fumitake
authors.initials: F
authors.lastname: Takahashi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shimaoka
authors.forename: Kevin
authors.initials: K
authors.lastname: Gardner
authors.forename: Akiko
authors.initials: A
authors.lastname: Kida
mesh_terms: D003252:Construction Materials; D006838:Hydrocarbons; D007564:Japan; D013499:Surface Properties
chemical_list: D006838:Hydrocarbons; C006647:asphalt