Under the cooperative agreement with DOE, the Research and Development Department of CONSOL Energy (CONSOL R&D), teamed with Universal Aggregates, LLC, to conduct a systematic study of the durability of aggregates manufactured using a variety of flue gas desulfurization (FGD), fluidized-bed combustion (FBC) and fly ash specimens with different chemical and physical properties and under different freeze/thaw, wet/dry and long-term natural weathering conditions. The objectives of the study are to establish the relationships among the durability and characteristics of FGD material, FBC ash and fly ash, and to identify the causes of durability problems, and, ultimately, to increase the utilization of FGD material, FBC ash and fly ash as a construction material. Manufactured aggregates made from FGD material, FBC ash and fly ash, and products made from those manufactured aggregates were used in the study. The project is divided into the following activities: sample collection and characterization; characterization and preparation of manufactured aggregates; determination of durability characteristics of manufactured aggregates; preparation and determination of durability characteristics of manufactured aggregate products; and data evaluation and reporting.