Fly Ash

Fly Ash is a by-product of coal-fired electric generating plants. The coal is pulverized and blown into burning chambers for immediate combustion. Heavier ash particles (bottom ash or slag) fall to the bottom of the burning chamber and the lighter ash particles (Fly Ash) fly out with the exhaust gas, thus the term Fly Ash. Before leaving the stack, these Fly Ash particles are removed and collected by electrostatic precipitators, bag houses or other methods. It is widely used to increase the strength of concrete, and to improve workability of fresh concrete. It reduces water demand, shrinkage and permeability of the finished product. Replacing cement with Fly Ash can significantly reduce the carbon footprint of concrete. Fly Ash is a pozzolan, meaning it is a siliceous and aluminous material that, in the presence of moisture, will combine with the lime liberated during the hydration of cement to form cementitious materials.