CEMENT EXPANSIVE COMPOSITION USING WASTE REFRACTORIES

摘要

PURPOSE: A cement expansive composition is provided to decrease cracking of cement mortar by using waste magnesia refractories of steel-making furnace as main materials. CONSTITUTION: The expansive composition for prevention of cracking due to shrinkage of cement mortar contains 75-85wt.% of waste magnesia refractories containing 50wt.% or more of magnesia generated from the melting furnace of iron mill and 15-25wt.% of calcined lime, wherein the magnesia(MgO) in waste refractories is expanded by formation of Mg(OH)2 from the reaction of water in hydration of cement. The resultant expansive materials are applied to flooring plaster, non-shrinkage grout mortar and self-compacting cement.