Crushed Slag. Provide material that: a. Is free of silt and clay, b. Meets the quality requirements in, c. Is reasonably uniform in density, and d. Has a dryrodded weight of at least 70 pounds per cubic foot. 3. Gravel and Chert. Screen gravel and chert. All oversize material may be crushed and fed uniformly back over the screen. The coarse aggregate portion shall conform to the ...