The demand for good-quality highway materials continues to increase whereas economical sources are becoming more limited. This demand may become more critical, especially with the policy (adopted by some state highway departments) of banning some aggregate types that have been frequently used in the past for producing paving mixtures.Steel slag aggregates have not yet been used extensively in pavement layers, even though they have been used successfully in the past. Steel slag has performed well in a number of surface-course applications subject to high traffic volumes (when such mixtures have been properly designed and constructed). Research, development, and demonstration work are still required to ensure the full exploitation of steel slag. The suitability of steel slag aggregates in combination with natural sand was evaluated for use in bituminous pavement surface layers constructed to serve high-volume, high-speed, and heavy-load traffic. This evaluation was made through a literature search, a field investigation, and a laboratory characterization of bituminous mixtures prepared with various gradations and proportions of steel slag aggregate. Marshall-sized specimens were tested in the laboratory for tensile characteristics, expansive properties after freeze-thaw cycling, and marshall stability. The field investigation included a surface condition survey and skid resistance measurements. Use of steel slag in asphaltic mixes is still highly localized in steel production areas. Some highway agencies do not permit its use, althoughthe performance record of steel slag mixtures is reported to be excellent. Some inputs should be considered in further evaluation of steel slag asphaltic mixtures. This process may lead to the development of technical specifications and recommendations for more extensiveuse of steel slag aggregates in pavement layers. This paper appearsin transportation research record no. 1269, Asphalt mix materials and mixtures 1990.
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