Ground-granulated blast-furnace slag (GGBS or GGBFS) is obtained by quenching molten iron slag (a by-product of iron and steel-making) from a blast furnace in water or steam, to produce a glassy, granular product that is then dried and ground into a fine powder.

The main components of blast furnace slag are CaO (30-50%), SiO2 (28-38%), Al2O3 (8-24%), and MgO (1-18%). In general increasing the CaO content of the slag results in raised slag basicity and an increase in compressive strength. The chemical composition shall consist of at least two-third by mass of the sum of calcium oxide (CaO), magnesium oxide ( MgO ) and silicon  dioxide (SiO2 ). The remainder shall be aluminum oxide (Al2O3) together with small amounts of other compounds. The ratio by mass (CaO + MgO )/  (SiO2) shall exceed 1,0.

Practical Applications:

GGBS is used to make durable concrete structures in combination with ordinary portland cement and/or other pozzolanic materials. GGBS has been widely used in Europe, and increasingly in the United States and in Asia for its superiority in concrete durability, extending the lifespan of buildings from fifty years to a hundred years. It is used for high performance concrete producing, all marine, sewage water works and where the massive concrete is poured.

Technical Benefits of Using Slag Powder in Concrete:

  • Lower permeability & high resistivity to alkalis attack.
  • Low heat of hydration & low internal cracks inside concrete.
  • Increase durability.
  • Lower concrete expansion & creep.
  • Improve the compressive strength either early & late age.
  • Lower the water to cement ratio.
  • Increase the resistivity against sulphates & alkalis reaction.


  • Packed in jumbo bags each of 1.5 ton.
  • Bulk in silo trucks.