Patent ID: 8088217

Claim:
A composition useful for producing a fire door core comprising an aqueous mixture of (A) expanded perlite and (B) a fast setting, cementitious component consisting essentially of (1) a hydraulic cement and (2) a pozzolan additive selected from the group consisting of (i) metakaolin, (ii) vitreous calcium aluminosilicate and (iii) mixtures thereof, which composition can be molded and shaped into a fire door core, and wherein, on a water-free basis, the expanded perlite (A) comprises about 65 to about 85 weight percent of the aqueous mixture, the fast-setting cementitious component (B) comprises about 15 to about 40 weight percent of the aqueous mixture, the organic binder (C) comprises about 1 to about 5 weight percent of the aqueous mixture and the fibrous reinforcement (D) comprises about 0.2 to about 1 weight percent of the aqueous mixture.