Chief engineer, National Slag Association, Alexandria, Va.
Pages: 12 Published: Jan 1982
Use of iron and steel slags as construction materials is believed to be the oldest and best developed “resource recovery” operation in the world. Iron blast-furnace slag use in the United States began more than 100 years ago with current use about equal to production. Steelmaking slags were largely wasted prior to World War II but are now used extensively in flexible pavement construction and railroad ballast. The 1979 Bureau of Mines data show use of nearly 36 million tons (32.5 × 106 Mg) of slag in commercial applications, replacing a similar amount of virgin materials.
Supplies of blast-furnace and steel slags are expected to increase by only a small amount during the remainder of this century. Use patterns will undergo marked changes, greatly increasing energy conservation and continuing conservation of virgin materials. Large amounts of blast-furnace slag will be processed for use as a cementitious material, saving both the virgin raw materials that would be used to produce a similar tonnage of portland cement and the huge amounts of energy used in cement kiln operation. Increasing recognition of the skid resistant characteristics of steelmaking slags will result in greater usage in asphalt concrete surface courses.
These changes in use patterns will decrease the amounts of slag available for use in base course and embankment construction. In many areas, it will be possible to use lower quality natural aggregates, recycled construction materials, or suitably processed wastes in these applications, thus further extending the supply of high quality virgin aggregates.
aggregates, cement, construction materials, energy conservation, recycling, resource recovery, slag, waste materials, concrete
Paper ID: STP32455S