Potential for acid leachate formation from air-cooled blast-furnace slag used in road construction
2009 (English)Conference paper, Presentation (Other academic)
Air-cooled blast-furnace slag (ACBFS) has suitable physical properties for use as an unbound aggregate in road bases. Results of laboratory leaching tests have also indicated that ACBFS can be used without posing any risk of negative environmental impacts. However, monitoring of drainages from a full-scale road test section with ACBFS has indicated that acid leachates (pH<6) with associated increased releases of constituents can occur under field conditions. In this paper, the potential and responsible mechanisms for acid leachate formation from ACBFS used in road construction are discussed. Analysis of a 10-year time series of drainage samples and 12 year old ACBFS from the road section indicates that acidity might develop from the oxidation of reduced sulphides released from the ACBFS. Currently, the impact of intermittent wetting and drying conditions on the weathering of minerals and leaching over time from ACBFS is investigated under controlled laboratory conditions to verify the field observations. A combination of chemical and mineralogical analyses is used to analyse the results.
Place, publisher, year, edition, pages
Research subject Waste Science and Technology
IdentifiersURN: urn:nbn:se:ltu:diva-31951Local ID: 645c0280-b8b0-11de-b769-000ea68e967bOAI: oai:DiVA.org:ltu-31951DiVA: diva2:1005185
International Conference on the Environmental and Technical Implications of Construction with Alternative Materials : 03/06/2009 - 05/06/2009
Godkänd; 2009; Bibliografisk uppgift: Værtspublikationsredaktører: Jacques Mehu; 20091014 (ysko)2016-09-302016-09-30Bibliographically approved