ISTRA 50 is a normal setting, rapid hardening Calcium Aluminate Cement with high early strength. It differs substantially from the usual calcium silicate cement (Portland cements) in its manufacturing process, chemical composition and rapid strength gain. ISTRA 50 is composed of calcium aluminates with high early strength, refractories, high abrasion resistance and resistance to biogenic sulphuric acid corrosion (BSAC).