Abstract: A building block comprises a transverse groove (12) in each end face (10b, 10c), an opening (15) extending from the first (10e) to the second bearing face (10d) in which a longitudinal groove (13, 14) is also provided. The block is further provided with reference and positioning structure comprising a pair of longitudinal seats on the first bearing face and a pair of projections, each divided into three projection portions, on the second bearing face. When a building structure is constructed, the blocks 10 are superposed dry and in a staggered arrangement in superposed rows, such that the longitudinal seats of each block engage the projections on the blocks of the underlying row. The apertures and the grooves in the blocks constituting the building structure form a grid of intersecting vertical and horizontal channels which extend over the entire building structure, and in which a binder is poured and solidifies, ensuring that the building structure is stable and resistant over time.

Abstract: A construction block of generally rectangular form having parallel upper and lower faces between which extend, through the block, one or more wide apertures and a plurality of narrow holes; the end faces of the block have wide grooves which cooperate, in a wall structure constructed from a plurality of horizontal courses of such blocks, to provide chambers between adjacent blocks of a course, the wide apertures in the blocks of adjacent courses cooperating to form vertically extending channels, the narrow holes house locating pins for holding the blocks of adjacent courses together until they are joined by concrete cast into the said vertical channels; the said upper and lower parallel faces have central depressions which form, between adjacent courses of blocks, horizontal channels linking the vertical channels so that the concrete cast into the vertical channels can also flow into and fill the horizontal channels to form an interlinked network giving great strength to the wall.