2517 Pebbles, gravel, broken or crushed stone, for concrete aggregates, for road metalling or for railway ballast, shingle and flint, whether or not heat-treated, macadam of slag, dross or similar industrial waste, whether or not incorporating the materials cited in the first part of the heading, tarred macadam, granules, chippings and powder, of stones of heading 2515 and 2516, whether or not heat-treated
2517 Pebbles, gravel, broken or crushed stone, for concrete aggregates, for road metalling or for railway ballast, shingle and flint, whether or not heat-treated, macadam of slag, dross or similar industrial waste, whether or not incorporating the materials cited in the first part of the heading, tarred macadam, granules, chippings and powder, of stones of heading 2515 and 2516, whether or not heat-treated