Abstract
Modified belite cement clinker containing $\alpha$'-C2S and C4A3 were syntehsized form the mixture of raw materials. $\alpha$'-C2S was stabilized at room temperature by adding borax. Properties of the clinker were charaterized with a XRD, SEM, TEM The additive effects of slag on the hydration properties were also estimated by measurement of compressive strength fluidity and heat evolution. The experimental results exhibited that the addition of slag to the belite cement improves the fluidity and early compressive strength due to the formation of ettringite and C-S-H. The compressive strengths of the mortar with 20% slag after 7, 90 days hydration were 212, 355 kgf/cm2 respectively.