| 摘要 |
A building block 500 has a surface with a plurality of spacing projections 520 to space the block from an adjacent block and at least one alignment projection 530 to align the block with an adjacent block. The spacing projections contact an adjacent block at a point or along a line, advantageously spacing it therefrom and preventing mortar from being trapped. Each spacing projection 520 may have a curved portion and is preferably hemispherical. The alignment projection is preferably received by a recess in an adjacent block. The alignment projection may have a plurality of spaced apart raised curved portions 534, which preferably abut at a point or a line of a recess when the spacing projections abut against a surface of an adjacent block. The alignment projection permits the flow of mortar out of the recess when it is inserted therein. The projections are preferably formed on the upper surface of a block, with a corresponding recess on its lower face. The block is preferably moulded from crushed stone and cement. |
