Class C fly ash results in which color concrete?

Class C fly ash is often used as a supplementary cementitious material, and it typically imparts a buff color to concrete. The reason for this coloration is due to the chemical composition and mineralogical characteristics of Class C fly ash, which is produced from the combustion of sub-bituminous coal and lignite.

In this context, the color of concrete can vary based on the type of fly ash used. Class C fly ash is known for its pozzolanic properties and can result in a lighter, more earthy tone, such as buff. This color is a direct result of its specific mineral content, which includes various oxides that lend the concrete its distinctive hue.

In contrast, other types of fly ash, such as Class F, often yield gray concrete due to their differing chemical compositions. Thus, understanding the source and characteristics of the fly ash is critical in predicting the final coloration of concrete.