The Ontario Building Code | Aggregates
9.3.1.4. Aggregates
(1) Aggregates shall,
(a) consist of sand, gravel, crushed rock, crushed air-cooled blast furnace slag, expanded shale or expanded clay conforming to CSA A23.1, "Concrete Materials and Methods of Concrete Construction", and
(b) be clean, well-graded and free of injurious amounts of organic and other deleterious material.