Scrubbing

Raw aggregates must often be cleaned before they can be used in construction projects, as deleterious materials, such as clay, can be harmful to the final product. Construction aggregate specifications allow for minimal contaminants in the final gradation, so as much of the impurities must be removed as possible. Sometimes, washing is all that is required to clean the aggregate. Other times, a more aggressive scrubbing is required to remove tough, sticky clays and other contaminants that have adhered to the sound aggregate.

Scrubbing allows producers to create a higher-quality product by removing the deleterious material, which can cause cracking, popouts and discoloration in the end-use product. Scrubbing is achieved with equipment designed to facilitate particle-on-particle attrition to remove these tough contaminants.