Quarry dust is regarded as a waste, and is usually dumped in places where it causes environmental problems. Replacement of sand with rock dust for road construction can reduce costs, and prevent mining of river beds. Rock dust can also be used as a mineral filler along with larger metal, on asphalt roads. Tar roads are surfaced with fine dust to prevent tar from sticking to the tyres.
Recent importance has been given to concrete roads. Replacing 40% of fine aggregates in concrete mixture with rock dust gives better strength than concrete from river sand.
After laying large metal, rock dust can be used as a filler. The surface is watered, and then compacted with a road roller. Substantial amounts of filler are required, with extensive road building, this can increase off-take of waste quarry dust. Normally soil is used as filler, so requirement for soil is eliminated. After the road is asphalted, a final finish is given by topping the road with fine dust. This prevents the tyres from sticking to the road.