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What are blended cements?

Q. What are blended cements and do they have standard specifications?

 

A.  Blended cements are defined by ACI CT-23 as a hydraulic cement consisting of portland cement uniformly mixed with slag cement or pozzolan, or both. These materials are combined to improve the performance of the cement in terms of durability, sustainability, and specific properties such as sulfate resistance. ASTM C595 provides prescriptive-based specifications for specific blended cements that consist of portland-cement clinker ground or blended with suitable proportions of limestone, granulated blast-furnace slag or natural or artificial pozzolans. These include portland-limestone cement (Type IL), portland blast-furnace slag cement (Type IS), portland pozzolan cement (Type IP), and ternary blended cement. ASTM also provides a performance-based specification with no prescriptive requirements (ASTM C1157).

 

References: SP-1(02); ACI 225R-23; ACI PRC-232.1-12; ACI PRC-233-17 ; CT-23;E3-13; ASTM C595; ASTM C1157

Topics in Concrete: Cementitious Material in Concrete; Materials in Concrete; Pozzolan