Fly ash is a by-product of coal burning thermal power plants. There are many utilization areas for fly ash in the industry. Because of high annual production volumes of fly ash, large volume applications like aggregate production seems to have a good potential to solve the disposal problem of fly ash. Composites and aggregates have been produced from high calcium fly ash of Soma Thermal Power Plant and their engineering properties have been measured. For high volume utilization of fly ash, aggregate production utilizing pelletization and pressing into specially designed molds have been realized successfully. Mechanical properties and durabililty tests were conducted on cured lightweight fly ash aggregates and five percent by weight lime added aggregates showed the best performance. It has been shown that different shapes of aggregates can be produced using the pressing technique. For the production of high performance composites, hydrated lime and metal powders with low melting point like bismuth, iron, aluminum and zinc have been mixed with fly ash. By pressing and sintering at various temperatures, composites have been produced and their mechanical properties have been measured. The composites which have been cured before sintering had the highest strength increase. The rate of increase of split tensile strengths of the sintered composites was higher than the rate of increase in their unconfmed compressive strengths.