Rectangular concrete pavement slab - has concave recessed bottom, providing stable bedding into sandy surface

摘要

The slab is for the surfacing of pavements, being between 20 and 40 cm in both length and width, and 2 to 6 cm thick. It has a recess occupying a large part of one of its main surfaces, and which can be of concave section, occupying all but the slab corner areas. The recess can have wall sections at right angles to the main surface where it joins onto the latter. The design ensures that the slab keeps stable once laid, no water accumulating in spaces formed between it and the sand etc. underneath.