Gravel and sand: size, shape and engineering uses

Gravel and sand describe size, not one universal material

Gravel and sand are aggregate size groups, but a product name does not fully describe engineering behaviour. Source rock, particle shape, cleanliness, grading and moisture also matter. A sieve boundary must be read within the selected classification or test standard rather than assumed to be universal. Natural deposits and crushed rock can both supply aggregate products. Their suitability depends on the intended concrete, mortar, pavement or drainage application. Similar colour and nominal size do not establish interchangeability. This guide separates source-rock identity from finished-product properties, explains why moisture is different from water absorption, and uses a hypothetical weighted-blend example to illustrate grading. A result applies to an identified sample and method; it is not automatic approval for every shipment or use. For a real project, compare representative samples and the complete set of required properties against its approved specifications.