We Supply Building Construction & concrete Additive Materials GGBS (GROUND GRANULATED BLAST FURNACE SLAG) 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.

Concrete made with GGBS cement sets more slowly than concrete made with ordinary Portland cement, depending on the amount of GGBS in the cementitious material, but also continues to gain strength over a longer period in production conditions. This results in lower heat of hydration and lower temperature rises, and makes avoiding cold joints easier, but may also affect construction schedules where quick setting is required.

MICRO SILICA or SILICA FUME Microsilica is a mineral admixture composed of very fine solid glassy spheres of silicon dioxide. Most microsilica particles are less than 1 micron (0.00004 inch) in diameter, generally 50 to 100 times finer than average cement or fly ash particles. Frequently called condensed silica fume, microsilica is a by-product of the industrial manufacture of ferrosilicon and metallic silicon in high-temperature electric arc furnaces.

HOW MICROSILICA WORKS IN CONCRETE Microsilica in concrete contributes to strength and durability two ways: as a pozzolan, microsilica provides a more uniform distribution and a greater volume of hydration products; as a filler, microsilica decreases the average size of pores in the cement paste. Used as an admixture, microsilica can improve the properties of both fresh and hardened concrete. Used as a partial replacement for cement, microsilica can substitute for energy-consuming cement without sacrifice of quality.

Addition of microsilica to a concrete mix alters the cement paste structure. The resulting paste contains more of the strong calcium-silicate hydrates and less of the weak and easily soluble calcium hydroxides than do