Usage of fly ash as a aggregate in the production of lightweight concrete

Fly ash is industrial waste from the coal generating thermal power plant. The fly ash is produced more than 15 million tones for year in Turkey, but only a small amount is utilized. When investigating chemical, physical and mechanical properties of fly ashes, we can see the large scale utilization in the construction sector and so on one hand we can manufacture material and energy production with a lower price and in the other hand with preventing the environ pollution we can protect the ecology balance. This study aimed to pellet specimens are manufactured from different power plant fly ashes and bentonite (as additive), this pellet specimens are used as a aggregate in production of lightweight concrete, the effect on the mechanical properties of the lightweight concrete is evaluated and the effort of expending the area of using fly ashes in Turkey is contributed. Industrial solid waste fly ashes in the experimental study were used and came from power plant Çayırhan, Orhaneli, Seyitömer, Çatalağzı, Tunçbilek and İskenderun Sugözü. In the first stage of the experimental studies, the chemical and physical properties were determined and pellet specimens were manufactured. Fresh knock, fresh crush, dry crush, sintered crush, moisture content and size of pellet specimens were analyzed. In the second experimental studies unit weight, specific gravity, sieve analyze, water absorption and lose freezing in the magnesium sulfate solution were determined. Finally, unit weight, water absorption, compressive strength and tensile splitting strength of lightweight concretes were determined, which are produced from fly ash aggregate. Key Words: Fly ash, Pelletization, Fly ash aggregate, Lightweight concrete and Strength