Fly ash cement is a type of compound cement with up to 30% fly ash content in Portland cement. KS recognized 3 types of fly ash cement. In comparison to Portland cement, fly ash cement has lower heat of hydration and water permeability and higher durability and chemical resistance. More recently, 2 types of cements with 20% fly ash contents were frequently used in highway pavement constructions. This is to prevent degrading durability due to alkali aggregate reactions.
HVFA cement is a type of compound cement with 30 to 60% fly ash contents. It has low heat of hydration and high fluidity. Mixed in ultra-low-heat and high fluidity concrete, it is used for large-scale constructions.