Why is fly ash (slag, XPM, silica fume…) used in concrete?
Supplemental cementitious materials such as fly ash are commonly referred to as pozzolans. Pozzolans have limited cementitious properties as individual materials but when introduced to a concrete mix, will combine with calcium hydroxide to form additional CSH paste. The materials can provide a cost savings to the concrete producer, extend additional durability features to the owner, be designed for high strength concrete and low heat of hydration applications. They also aid the flat work finisher with better workability and finishing.
