The manufacture of coated roadstone demands the combination of a number of aggregates, sand and a filler (such as stone dust), in the correct proportions, heated, and finally coated with a binder, usually bitumen based or, in some cases tar, although tar was removed from BS4987 in 2001 and is not referred to in BSEN 13108/1.
The production of coated roadstone requires a blend of aggregates, sand, and filler (such as stone dust), in precise proportions, heated, and finally coated with a binder, typically bitumen-based or tar, although tar was eliminated from BS4987 in 2001 and is not mentioned in BS EN 13108/1.