Standards & Specifications

A0 - Aggregates

This Section covers the routine use of most types of aggregates.

There are topic pages for:

• Mortar sands
• Sand and gravel
• Crushed rock aggregates
• Unbound aggregates for road construction
• Recycled aggregates
• BS EN Standards for aggregates
• Test methods for aggregates
• Factory production control for aggregates.

The Other Products Section has details of specialist uses for aggregates in:

• Agricultural limestone
• Armourstone
• Limestone powders
• Quicklime and hydrated lime
• Rail ballast
• Silica sands.

Aggregate sizes

Standards for aggregates use a size designation based on:

d - Lower sieve size With some particles passing (undersize)
D - Upper sieve size With some particles retained (oversize)

The current Standards have also introduced some new sieve sizes. For example:

0 - Used as the lower (d) sieve size for ‘all-in’ aggregates
2mm - Replaced the 2.36mm and 3.35mm sieve size
4mm - Replaced the 5mm sieve size
8mm - Used as the lower (d) sieve size for some products
31.5mm - Replaced the 28mm and (37.5mm) sieve size
40mm - Replaced the 37.5mm sieve size for some products

The 2.8mm, 12.5mm and 16mm test sieves are also used in some specifications and test methods.

The changes mean that the traditional terminology for aggregate sizes becomes:

20mm all-in changes to: 0/20mm size all-in
20 to 5mm graded changes to: 4/20mm size graded
10mm single size changes to: 4/10mm single size
20mm single size change to: 10/20mm single size.