Durability of concrete using electric arc furnace oxidizing slag aggregates

This paper presents the possibility of utilization as concrete aggregate of electric arc furnace oxidizing slag (EF oxidizing slag), which has hardly been used as concrete aggregates because of deterioration caused by the hydration of f-CaO, f-MgO and unstable minerals included in the slag. Three types of slag aggregates made in different cooling processes i.e. air granulated EF oxidizing slag, water-granulated EF oxidizing slag and air-cooled EF oxidizing slag are used. The chemical and mineralogical test results show only a very small amount of f-CaO and f-MgO and do not detected unstable minerals. The durability of slag concrete is investigated by the measurement of length change, strength, etc., and the results are discussed in comparison with concrete using rock aggregates. It is shown that air granulated EF oxidizing slag aggregate is stable by the results of length change test, but water-granulated and air-cooled EF oxidizing slag aggregates are a little expansive behavior.