Interlocking building block

An improved interlocking block for a mortarless wall assembly in which a plurality of such blocks are interlocked together to create a substantially continuous planar wall surface having a plurality of stacked linear courses of such blocks bonded together internally by cementitious bonding material, the blocks in each course being mechanically interlocked in end to end relation, with adjacent blocks on the same course, the blocks in a given one of said courses being mechanically interlocked in a staggered relation to the blocks in the abutting courses in said stack, said blocks comprising:

• (a) a pair of spaced, parallel, upright sidewalls having flat top and bottom surfaces, said sidewalls having block-interlocking means on opposed ends thereof;
• and
• (b) at least one transverse upright support web spanning said sidewalls and integral and defining a cavity therewith for receiving said cementitious material therein, said web having a concavity disposed at the upper end of one side thereof and a complimentary convexity disposed at the lower end of said one side, said convexity uniformly sloping upwardly into said concavity, the opposite side of said web sloping upwardly toward said one side, said web is shaped for facilitating release of said block from its forming mold for reducing mold wear thereby and to provide an increased surface area for improving adhesion of said cementitious bonding material thereto when poured into the cavities of said blocks when said blocks are stacked to form said continuous planar wall surface, the upper surface of said web is divided by parallel slits into three separate knockoff portions any one of which can be removed to permit the addition of reinforcing bars extending longitudinally through the block of each course while maintaining the block of abutting courses in their mechanically interlocked relationship.