Stackable building block, such as breeze block - has tenon and mortise joints and tongue and groove joints

摘要

Very liquid cement is used to bond the blocks so that the joints fit tightly together. Stop-pieces for the cement are positioned at each end of the block and in the middle. Apertures on each block open out onto its horizontal surfaces so that air circulates up through a wall built of the blocks. The top and bottom surfaces may have cooperating projections and grooves. Ducts leading from a central groove obliquely to the side edges of the block, distribute the cement along the sides of the blocks. The blocks are moulded from a mixture of concrete and expanded clay.