Ask a quarry for stone and you will hear several different names. Names and exact sizes vary from one quarry and one country to another, but the main product groups are similar. Understanding them helps you order the right material and avoid paying for something you do not need.

How a crusher produces different sizes

A stone crusher breaks large rock into smaller pieces. The pieces then pass over screens (sieves) that separate them into size groups. Changing the crusher settings and the screens changes what you get. Operators can aim the output at different products depending on demand. For an example of a mobile diesel crusher used in quarries, see our article on the 7 to 30 ton per hour diesel stone crusher.

Common products

• Hardcore (large rubble): big, rough pieces used as fill and as a base under floors and foundations.
• Ballast (mixed aggregate): a blend of stone sizes, often used with sand and cement to make concrete for slabs, beams and columns.
• Chippings: smaller, graded pieces, such as around 10 to 20 mm. Used in concrete, drainage and as a surface layer.
• Fine chippings: very small stone, used in precast products such as paving blocks and in fine concrete.
• Quarry dust (crusher dust): the finest fraction. It can replace part of the sand in some applications, but quality and dust content matter, so ask your engineer.

Why shape and cleanliness matter

For concrete, aggregates should be hard, strong and clean. Dusty or clay-coated stone reduces the bond with cement. Angular, well-graded stone packs tightly and makes stronger, more economical concrete.

How to order sensibly

1. Tell the supplier what the stone is for (concrete, paving blocks, drainage, base layer).
2. Ask for the nominal size range, not just a local name.
3. Check a sample for cleanliness and shape.
4. Check how the supplier measures quantity, by tonne, tipper or cubic metre.

Where aggregates are used

Crushed stone goes into concrete blocks, paving blocks, the base layers described in paving block thickness and patterns, and structural concrete. Concrete products such as fence posts also depend on good aggregate.

• aggregates
• ballast
• stone crusher