Steel slag aggregates have been used in premium surface course hot-mix asphalt for Ontario highways since the early 1970s. Asphalt pavement performance problems led to the Ontario Ministry of Transportation imposing a moratorium on the use on steel slag aggregates in late 1991. The problem has been investigated from the steelmakers producing the slag through to hot-mix design and production. Steel slag can make good aggregate for use in hot-mix asphalt if the volume expansion of the slag is controlled. Performance based testing of steel slag aggregates, particularly volume stability, is recommended as a measure of the aggregate quality. Practices at the steelmaker and the slag processor were examined. The production of acceptable quality steel slag aggregates requires a total quality management of all steps of aggregate production and processing, and hot mix production and placement. (A)
Samenvatting