Aggregates for Concrete
2021-8-9 · Crushed stone is produced by crushing quarry rock, boul-ders, cobbles, or large-size gravel. Crushed air-cooled blast-furnace slag is also used as fine or coarse aggregate. The aggregates are usually washed and graded at the pit or plant. Some variation in the type, quality, cleanli-ness, grading, moisture content, and other properties is expected.