20110239570 | Concrete Masonry Hollow Block - A building block having a body with three sets of opposing outer sides defining a generally rectangular outer shape, the body having at least one passageway having an upper open end at a top of the block and an open lower end at a bottom of the block. An inner part of the block is comprises of a first material, and a second different material surrounds the inner part providing a substantially continuous outer surface of said second material. At least one side of one of the sets of opposing sides has at least one protrusion extending outwardly therefrom, and at least one cavity is provided in the opposed side in a position and of a size to receive and effect an alignment of a further block having the same shape and size of this first defined block, by receiving the at least one protrusion into the cavity or cavities. | 10-06-2011 |