Upgrading of Low-Quality Aggregates for PCC and Bituminous Pavements

摘要

As the availability of aggregates from proven sources diminishes and haul distances for quality aggregates increase, the feasibility of upgrading poor or marginal aggregates takes on increasing promise. This project investigated the potential for upgrading poor or marginal aggregates for portland cement concrete and bituminous paving mixtures. The primary methods studied used materials that were representative of classes of materials used in impregnations and coatings. Chemical treatments (admixtures) were also considered where applicable, representing current practice in the case of bituminous mixtures. Mechanical beneficiation techniques were specifically excluded, as was aggregate upgrading for the purpose of improving skid resistance. A preliminary guide is presented, detailing field evauation (pilot plant) studies of the upgrading methods/materials found in the research to be technically suitable.