Use of aggregate screenings as a substitute for silica sand in portland cement concrete (PCC).

681603801Final report.PDFTech ReportBDL-13 977-01Portland cement concreteAggregatesSandGlassFloridaFlorida. Dept. of TransportationGurjar, Ashok H.Embry-Riddle Aeronautical University. Dept. of Civil EngineeringNTL-HIGHWAY/ROAD TRANSPORTATION-MaterialsUS Transportation CollectionThe State of Florida is the third largest consumer of crushed rock products in the United States and is the largestsingle contractor/user of crushed stone resources in the state. Crushed stone in Florida is produced fromlimestone, which is mined or extracted from naturally occurring deposits. This crushing for coarse aggregateresults in a fine byproduct called screenings. The stockpiling and disposal of fines produced as a result ofaggregate crushing and production operations are some of the major problems facing the aggregate industry.This project investigated the use of these screenings as a substitute for natural sand in PCC. Influence ofscreenings was tested in the mortar and in concrete specimens for fresh and hardened state properties, includingflow, strength and durability. It is concluded that the screenings can be used safely in blended form for projectswhere durability is not the main concern