Compressive strength development of blended cement concretes containing portland cement, fly ash and metakaolin

This paper investigates the compressive strength development of binary and ternary cement concretes containing Portland cement, fly ash and metakaolin at various ages and water/cement ratios. The material costs and embodied carbon dioxide (e-CO₂) levels of these concretes at the strength of 45 N/mm² are also presented. The results suggest that metakaolin improves compressive strength at both early and later ages, while fly ash contributes to strength development at later ages. The concretes made with blended cements have lower e-CO₂ levels than those made with Portland cement. The cost data suggest that at 45 N/mm² strength, economic blended cement concretes are possible when the level of metakaolin blending is kept at 5%.