The synergetic effect of SCMs, fly ash (F) and calcined clay(C) in ternary mixes at 20% replacement was evaluated. It was found that due to the complementary water demand of F and C, pastes made of ternary blends of FC-OPC showed similar or better rheology than OPC pastes. This was coupled with an increase in heat evolved during early age of hydration and a comparable 28 days compressive strength. The results indicate that ternary mix of FC-OPC can be future green cements, where C can be utilized even in the transition stage with existing SCM, such as F.publishedVersio