US Patent 7770345 Floor tile with adhesively joined concrete sub-blocks

A floor tile for a raised floor. The floor tile is defined by a shallow upwardly-opening metal pan defining a shallow compartment in which a main preformed one-piece concrete block is secured. The main concrete block is preferably formed from a plurality of one-piece preformed concrete sub-blocks which are adhesively adhered in sideward abutting relationship to define a plan profile corresponding to the main concrete block. The main concrete block is then adhesively secured within the compartment of the metal pan.