When it comes to strength, 10mm concrete aggregate is expected to be stronger than 20mm concrete aggregate. This is because the 10mm size is easier to fill small spaces and easier to compact. It is used for high strength mixes along with 20mm and other specialized batch mixes. This study focuses on how different sizes of granite affect the strength and performance of concrete for various structural components, such as beams and columns.
Aggregates are a broad category of materials, such as sand, gravel, crushed stone, slag, and recycled concrete. Concrete aggregates are produced to Australian standards (AS 275) or to more specific customer requirements. Generally, smaller coarse-grated aggregates are used for stronger concrete, with 20mm aggregates meeting the threshold for strong concrete and 40mm aggregates for normal strength concrete. For medium strength concrete, 40mm aggregates should be used, while for high strength, 20mm is best.
It can be a single size material, typically 20 mm, 14 mm, 10 mm, or 7 mm, or a graded aggregate consisting of a single size aggregate mixture. The shape of the aggregates is important for the workability of the concrete, the quantity you want to place, and the strength of the concrete you want to make. However, for structural applications 40mm is usually the highest you'll want to go unless you're running a mass concreting project such as a dam.