Supplementary
cementitious materials such as fly ash, granule blast furnace slag
and silica fume enable the concrete industry to use hundreds of
millions of tons of by product materials that would otherwise be
used as land-filled as in the west. Furthermore, supplementary
cementitious materials reduce the consumption of Portland cement
per unit volume of concrete. Portland cement has high
energy quantities and emissions associated with its manufacture,
which is conserved or decreased when the amount used in concrete
is reduced.