STEEL SLAG IN HOT MIX ASPHALT CONCRETE

In September 1994, steel slag test and control sections were constructed in Oregon to evaluate the use of steel slag in hot mix asphalt concrete (HMAC). This report covers the construction and five-year performance of a pavement constructed with 30% steel slag. Asphalt concrete can be produced and the pavement constructed readily in Oregon when crushed steel slag is used as a portion of the aggregate. If the unit cost of steel slag modified mixes is the same as conventional dense graded mixes, overall project costs may increase because of the decrease in coverage by the heavier steel slag mix. For the test section HMAC constructed with 30% steel slag, the coverage was 15% less than a conventional "B" mix. Reported increased resistance to rutting and improved skid resistance was not measured during the five years the pavements have been monitored. The differences between the two sections may not be measurable because only 30% steel slag was used in the test mix and the slag was finer than the conventional 1/2 - 1/4 in. (12.7 to 6.3 mm) material it replaced. To date, both the control and test sections are performing satisfactorily.