Aggregates for Paving and Drainage | Pavingexpert
Being considerably less dense than sand or other quarry products, ash was a bedding material muchadmired by the laying gangs, as it is easy to cart and to spread, and compacted well. ... In some parts of the country, 'allin ballast' refers to a mixture of gravel and/or small stone (<60mm) with sand, often used to make concrete. Elsewhere, it ...